Spreads to View - WRAP min technical.pdf · waste, PFA Specification of materials with low environmental impact (e.g. those that are ‘A’ rated in the Green Guide to Specification)

Practical solutions for sustainable construction

Delivering effective Waste MinimisationTechnical guidance for construction clients, design teams and contractors

WRAP works in partnership toencourage and enable businessesand consumers to be more efficientin their use of materials andrecycle more things more often.This helps to minimise landfill,reduce carbon emissions andimprove our environment.

Contents

Executive summary 01

Introduction 03

Good practice Waste Minimisation 04

Setting requirements for Waste Minimisation 05

Why is Waste Minimisation important? 06

Understanding Waste Minimisation 08

Waste Minimisation opportunities 10

Guidance Note 1 Communication 13

Guidance Note 2 Design 16

Guidance Note 3 Procurement 29

Guidance Note 4 Logistics 41

Conclusion 46

Executive summary

Delivering effective Waste Minimisation 01

Implementing good practice WasteMinimisation and Management (WMM) onconstruction projects will help reduce thesignificant quantities of construction wastesent to landfill andmake a substantialcontribution to sustainable development.

This guidance is part of a suite of threedocuments that focus specifically on wasteminimisation. The other guidance documentsprovide a high-level business case for clientdecision makers and a summary guidance toset out how clients and contractors can makewaste minimisation a contractual requirement.

The aim of this document is to providepractical guidance on how to deliver againstclient requirements for waste minimisationintroduced in WRAP, Achieving effectiveWaste Minimisation. It provides a morecomprehensive look at the opportunitiesthat exist to reduce waste on constructionprojects and provides a series of checklistsand proformas to aid design teams andcontractors in doing so.

The focus of this guidance is to assistmain construction clients, design teams,contractors and their supply chains toreduce waste on their construction projects.It provides detailed technical guidance onhow good practice waste minimisation canbe delivered both at site and strategic levels. Itsets out what is meant by waste minimisation,why it is important, who should implement itand how it can be effectively implemented atthe project level after beingmade an explicitrequirement of the procurement process.Model forms of words to be set in contractssuch that all parties have formal commitmentsto reduce waste are provided in the guidance,WRAP, Achieving effective Waste Minimisation.

This guidance builds upon the structure ofthe parallel WRAP guidance document onwaste management, Delivering good practiceWaste Managementwhich contains 10 guidancenotes – covering setting project requirementsthrough to reviewing performance. GuidanceNote 2: Design explores waste minimisationand this document builds upon this guidancenote, going into more detail.www.wrap.org.uk/construction

Unlike waste management, wasteminimisation does not follow a set ofprocesses (such as developing a Site WasteManagement Plan (SWMP)). Instead, effectivewaste minimisation requires a change inattitude towards waste. If all members of theproject team are committed to identifying andreducing waste then reductions can be madein a number of areas of opportunity includingdesign, procurement and logistics, as seenbelow. The guidance notes in this documentwill provide the technical ‘know-how’ of theseopportunities to reduce waste and support theproject team to consider and act upon thesethrough each stage of the construction processso to deliver against the client’s requirement.

The guidance notes are summarised below.

Guidance Note 1: CommunicationCentral to waste minimisation iscommunication. Project teams need to thinkabout waste differently. Waste needs to beraised up the agenda so that when designdecisions are made, or logistics strategiesdeveloped, the impact upon waste isconsidered and action is taken. Wastemust be discussed and targeted throughoutconstruction. Fundamental to this is opencommunication where innovative solutionsare actively encouraged to target waste. Thiscan be facilitated through allocating time inproject meetings to the waste agenda orthrough waste workshops where all partiesare engaged.

Opportunities to minimise waste arise throughout a project, whichfall into four key categories and form the basis of the guidance sheetsin this document

Delivery

Design

ProcurementPlanning

LogisticsPlanning Delivery

Communication

Project timeline

02 Delivering effective Waste Minimisation

Guidance Note 2: DesignDesign presents some the greatestopportunities to influence waste. The principleof waste minimisation in design includes‘designing out waste,’ the use of efficientdesign and planning to reduce the quantity ofwaste before it arises onsite and the useof MMC. Failure to think about waste duringdesign means that the contractor is oftenunable to reduce some of the wastefulelements which have been ‘locked in’ bythe designer. Therefore, getting the designright – i.e. ensuring that wasteful elementsare addressed – means that the contractor’srole is much simpler.

Checklists are provided to aid the Client team,Design team and Constructor team to addressconstruction waste in design.

Guidance Note 3: ProcurementThe principle of waste minimisation inprocurement involves producing accurateestimates of materials required and then usingthese materials more efficiently. The quantityof materials ordered is often inaccurate andunreliable and results in over ordering andmaterial wastage. This is an area where costscan be saved through buying better. There isscope for waste (and its associated cost) to beaccurately estimated, controlled and reducedduring procurement.

A series of checklists and proformas areprovided. These are aimed at subcontractorsfor improving the material ordering process interms of robust allowances for waste and datagathering on howmuch waste is generated soto improve the waste profile. Potential actionsby subcontractors are provided in four stages:

planning;implementation;review; andimprovement.

Guidance Note 4: LogisticsEfficient logistics can play a large part inreducing waste derived in transit to or onsite. The development of a robust logisticsplan is fundamental to effectively reducewaste. A logistics plan identifies howmaterialsare moved to, from and on site and how theyare stored. Efficient logistics is based on therigorous assessment of the need for materials,coordinating delivery, storage and distribution.WRAP are currently developing a logistics plantemplate guidance document.

1.0 Introduction


The construction industry is the UK’s largestconsumer of natural resources, using over400 million tonnes of material per annum.It generates more than one-third of the UK’swaste arisings, of which only half is reusedor recycled (primarily aggregates and metals).Over 60 million tonnes of construction sectorwaste is sent to landfill or similar disposalsites every year.

More efficient use of materials wouldmake a major contribution to reducingthe environmental impacts of constructionincluding reducing demand for landfill andthe depletion of finite, natural resources.This would also contribute to the economicefficiency of the sector and of the UK asa whole.

Major improvements in materials efficiencyare possible, without increasing cost by:

minimising the overall creation ofwaste resulting from, for example,over-ordering or inefficient design;reducing the quantity of material sent tolandfill during the construction processthrough effective waste management;recycling materials already on theconstruction site into the newconstruction project; andusingmore recycledmaterials andmainstream products with higherrecycled content.

Taking action in each of these areas in thesequential order outlined in figure 1.1 (right),would enable construction projects to achievegood or best practice waste minimisation andmanagement (WMM). Waste minimisation canbe seen in the context of overall materialsefficiency and wider sustainability goals infigure 1.2 (right).

Figure 1.1: Sequence of actions to achieve resource efficiency

Figure 1.2: Waste minimisation in the context of overall materialresource efficiency and wider sustainability goals

Utilising materialsrecovered onsite or

locally e.g. constructionand demolition

waste, PFA

Specification of materialswith low environmentalimpact (e.g. those that

are ‘A’ rated in the GreenGuide to Specification)

Materials in(produce &materialsselection)

Materialsout (goodpracticeWMM)

Energy

Efficient use offinite natural materials

Minimisingenvironmental damage

Waste avoidanceand minimisation,e.g. through offsitemanufacturing and

stock control

Procurement of productscontaining higher than

standard levels ofrecycled content

Returning packaging andsurplus materials (e.g. plasterboard off cuts)

for reuse/recycling

Reducing the total amount of materials

in a design

Collection, segregationand recycling of wastes

Materials Water

Key sustainability goals

Waste minimisationand management

Procurement ofrecycled content

Materials recycling

2.0 Good practice Waste Minimisation

Implementing strategies to minimise waste isthe first step towards materials efficiency andis one of the most effective ways to solve thewaste problem in the construction industry.Minimising waste eliminates the need forsubsequent handling.

After opportunities in waste minimisationare exhausted, waste that is produced can besubsequently managed. The primary focus ofthis document is on the range of opportunitiesfor waste minimisation in construction. Forfurther guidance on waste management andoverall good practice WMM please see WRAP,Achieving good practice Waste Minimisation andManagement, Guidance for construction clients,design teams and contractors on WRAP’swebsite: www.wrap.org/construction

Waste minimisation involves challengingdesign and construction decisions atregular intervals; at pre-design, design& procurement, pre-construction andconstruction stages. Reducing waste is nota one off process but must be continuallyrevisited throughout a project.

To effectively reduce waste one must addressdesign, procurement and logistics activitiestargeting waste generating activities in each.Best results are achieved when all membersof the design and construction team combinein looking for and reducing waste throughthe construction process. Continual andclear communication is necessary to achievethis outcome. Figure 2.2 (left) illustrates thekey areas of opportunity to target wastereduction efforts.

Below is an illustration of the waste hierarchy(figure 2.1). This follows the principle of‘reduce, reuse, and recycle’. At the top ofthis list, and therefore the top priority, iswaste reduction.

Figure 2.1: The waste hierarchy

Wastereduction

Reuse

Recycling andcomposting

Energy recoverywith heat and power

Landfill with energy

Landfill


Figure 2.2: Key areas of opportunity to minimise waste in design,procurement and logistics activities. Continual communication ofopportunities between project teams and the supply chain will keepwaste on the agenda

Delivery

Design opportunities

Procurement opportunitiesPlanning

Logistics opportunitiesPlanning Delivery

Communication opportunities

Project timeline

3.0 Setting requirements for Waste Minimisation


Clients can and are encouraged to providea mandate for action on all constructionprojects by setting a requirement for wasteminimisation (and waste management). Thissimple action will be the crucial first step inrealising the key benefits of becoming efficientwith materials usage.

The client’s core requirement can be setas follows:

‘…we require a Site Waste ManagementPlan (SWMP) to be developed from the pre-design stage to inform the adoption of goodpractice waste minimisation in design, andfor the SWMP to be implemented in allconstruction site activities in line with goodpractice published by WRAP. The SWMP isrequired to set targets for waste reductionand recovery based on an assessment ofthe likely composition and quantity of wastearisings and identification of the mostsignificant cost-effective options forimprovement (Quick Wins). This shouldbe supplemented by information on how thetargets will be achieved during constructionactivities and how the actual levels of wastereduction and recovery will be monitored forcomparison with the targets set.’

A high-level requirement will provide amandate for action so that waste minimisation(and management) is included in all aspectsof project procurement as seen in Figure 3.1.For example, emphasising waste in the projectbrief will ensure contractors invited to tenderare qualified and experienced in wasteminimisation. Furthermore, setting targetsand requirements in contract clauses willhold the contractor and their supply chainaccountable. In essence, waste minimisationcan cascade throughout all aspects of projectprocurement. This will ensure roles andresponsibilities for implementing wasteminimisation strategies are clear andactionable. For more information on settingrequirements and exemplar forms of words,please see WRAP, Achieving effective WasteMinimisation guidance.

Figure 3.1: A high-level policy client requirement for wasteminimisation (andmanagement) is readily cascaded to the projectlevel through the procurement process. WRAP, Achieving effectiveWaste Minimisation provides model wording for each of theseprocurement steps

Policy statement

Project information/briefs

Pre-qualification

Appointmentof designers

Contractclauses

Tenderspecifications/briefs

Employer’srequirements

Pre-project

Briefing

Design/pre-construction Traditionalprocurement

Design and buildprocurement

Appointmentof contractors

4.0 Why is Waste Minimisation important?

Waste minimisation delivers a compellingrange of benefits. In particular, reducing wastehas two principle benefits:

a reduction in the amount of materialentering the waste stream reduces theenvironmental impact of construction; anda reduction in waste can resultin significant cost savings – see‘The True Cost of Waste’ below.

In addition, there are some other considerablebenefits which, when combined provide astrong incentive to reduce waste.

minimising environmental damage –reduced waste means less quantityof landfill space used and reducedenvironmental impacts associatedwith extracting, transporting andmanufacturing/processing the rawmaterials of the construction process;

conserving natural resource – a reductionin the amount of materials actuallyrequired for a project and the specificationof reused and recycled materials andpackaging onsite results in less demandfor primary materials, thereby stimulatingthe market for recycled materialsamongst product manufacturers andencouraging higher levels of recyclingthroughout the economy;

increased competitive differentiation –benefits both developers and contractors,in terms of project efficiency througha reduction in construction costs andprogramme. This is particularly sowhere waste minimisation opportunitieswill help to meet prospective client’ssustainability objectives;

responding to and pre-empting publicpolicy – those organisations respondingto the thrust of public policy for increasedsustainability in construction and the builtenvironment will be in an advantageousposition in comparison with those thatwait until they are compelled to act bylegislation;

increased performance against CSRobjectives – real performance againstcorporate responsibility and sustainabilitypolicies can be quantified, therebymeeting the expectations of externalstakeholders and employees andenhancing corporate image; and

lower CO2 emissions – avoiding theneed to transport wasted materialsboth to and from site results in a dropin CO2 emissions.


The True Cost of WasteThe true cost of waste disposal is not just the cost of paying a waste contractor to removea skip from site, as illustrated below.

There are also some additional costs not covered in the above, these are:� the time taken by on-site sorting, handling and managing waste; and� poor packing or overfilling of skips leading to double handling (this cost is very difficult to

quantify).

As an example, the true cost of filling and disposing of one skip with mixed constructionwaste in one study1 was found to be £1,343 although the skip hire was only £85.

The true cost of construction waste will continue to rise substantially each year due to:� Landfill Tax increasing each year;� higher disposal costs; and� taxes and levies on primary materials.

Purchase cost ofthe delivered

materials wasted

Cost of wastestorage, transport,

treatment anddisposal

Loss of not sellingwaste for salvageor not recycling

+ +


Key public policy driversThere is an increasing thrust of European,UK national and local policies and legislation toachieve greater resource efficiency and reducewaste sent to landfill from the constructionindustry. In addition tomandatory targets, manyorganisations are voluntarily applying targetsto their projects to demonstrate their corporatesocial responsibility. While there is currentlyno regulatory obligation to reduce andmanagewaste, there are some obvious shifts towardsgreater efficiency across the industry.

Landfill Tax was introduced to encourageorganisations to reduce the amount ofwaste disposed to landfill. There are tworates of tax: a standard rate of £24 pertonne for active waste (substances thateither decay or contaminate land) anda lower rate of £2 per tonne for inertmaterials (including rocks, soils, ceramicsand concrete). The standard rate is due toincrease by £8 per tonne until 2010/11 andthe lower rate will increase from £2 to£2.50 per tonne in 2008. The proposedincreases therefore provide a strongfinancial incentive to reduce waste withimmediate effect.

Site Waste Management Plans (SWMPs) –it is expected that the use of SWMPswill become a mandatory requirementfor many projects throughout the UK inthe near future. Although SWMPs relateprimarily to managing waste produced onsite, they should be developed during thedesign stage to act as an effective tool toinform the design process and addressthe waste problem at its source. TheSWMP will provide information, such aspotential waste streams and their likelyquantity, to enable strategic decisionsto be made regarding the design andsupply chain.

The Code for Sustainable Homes (CSH)is a voluntary scheme developed by theGovernment and Industry, and is expectedto become mandatory in 2008. The CSHfocuses on new build housing with theexpectation that it will be adapted toapply to all buildings in the longer term.A specific requirement within the CSHis for a SWMP to be developed. Furtherpoints are awarded where the SWMPincludes procedures and commitmentsthat minimise waste in accordancewith WRAP/Envirowise guidance.For further information, please referto WRAP guidance on the Code forSustainable Homes available fromwww.wrap.org.uk/construction

5.0 Understanding Waste Minimisation

How is waste generated?This guidance refers to the physical wastegenerated on site. It does not address wastedtime and or money, albeit these are closelylinked to the inefficient use of materials.

The main sources of waste found inconstruction projects1 include:

demolition material – site clearanceoften leads to disposal of large quantitiesof materials;damage – to materials either duringdelivery or during storage on site(handling errors, inadequate storage,poor coordination with other trades);off-cuts – of materials resulting frominefficient design and constructionpractices;design changes – leading to reworkingand wasted materials;temporary worksmaterials(e.g. formworks, hoarding, etc);contamination of ‘clean’ waste; andpackaging.

How tominimise wasteWaste minimisation involves taking actionto reduce these sources of waste.Opportunities to reduce waste are presentedin guidance sheets across four broad areas:

communication;design;procurement; andlogistics.

Each of these areas contains severalopportunities that can help reduce wasteon your project. Not every opportunity isapplicable in all cases but this guide shouldgive sufficient information to begin to makereal changes on a project. Figure 5.1 providesa ‘snapshot’ of where the key opportunitiesare to reduce waste – divided across theabove categories addressing each of thewaste source identified above.

Table 5.1 puts key opportunities into thecontext of the guidance notes provided inthis document.

Unlike waste management there is nota simple process that can be followed onall projects (like developing a Site WasteManagement Plan) but instead, project teamsshould make themselves aware of wastereduction opportunities within this guidanceand target improvements wherever possible.


1 WRAP, ‘Reducing material wastage in construction, Guidance for clients, contractors and subcontractors on how to deliver good practice in material call-off, buying and usage’.

To reduce waste one must address briefing, design, procurement,logistics and site activities, targeting waste generating activities ineach. Best results are achieved when all members of the designand construction team work together to reduce waste throughthe construction process.

Figure 5.1: Opportunity curve of waste minimisation opportunities during the project life cycle

• Pre-design • Masterplanning• Outline design• Specifications

• Detailed design• Specifications

• Procurement • Construction • Postconstruction

Projecttimeline

Opp

ortu

nity

toin

flue

nce

was

tere

duct

ion


Table 5.1: Areas of waste minimisation opportunities: communication, design, procurementand logistics, with an example of a solution to reduce a specific waste

Areas where you canWaste make a change Possible solution to reduce waste

Communication Design Procure Logistics

Demolition � � � � Opportunity for reuse of existing structure

Materials from � � � � Opportunities for reuse and/or recycling ofdemolition/ demolition/site clearance materialssite clearance

Temporary works � � � � Choice of appropriate constructionmethod

Excavated material � � � � Ground enabling options: cut and fill balance, correctfoundation depths etc

Design change � � Have a flexible approach to design

� � � Use design freezes to avoid change

Design decisions � � Use off site manufacture to avoid site waste

� � Standardise designs to increase repetition

Off-cuts � � � Simplify building form to reduce site cutting

� � Dimensional requirements coordinated with specifiedmaterial/product

� � Appropriate tolerance allowance

� � Materials setting out correctly

� � � Accurate workmanship

Over-ordering � � Produce accurate estimates of material requirements

� � � Avoidance of over-ordering of materials

� � � Appropriate allowance for waste

Damaged materials � � � Adequate protection

� � � Appropriate storage

� � � � Appropriate handling/logistics

� � � Just in time delivery

Packaging � � � Encourage take back or elimination

Contamination of � � Efficient site waste management‘clean’ waste

There are a wide range of waste reducingopportunities starting at the earliest part ofdesign and project briefing, right through tothe construction and site activities. Of theseopportunities, those with the largest impacton waste are in the early stages of design –when the design is most flexible and canaccommodate solutions to reduce waste.

The opportunity curve (Figure 5.1) on page 8illustrates this point. At these early masterplanning stages there is greater flexibility tochange the design and specification to improvethe waste likely to be generated. Fundamentaldecisions about building shape and form aretaken, each having a significant (if not alwaysapparent) impact upon waste.

As the design develops, constraints areintroduced. This means that there isincreasingly less scope to modify the designto reduce waste – albeit there are almostalways minor improvements which can bemade with minimal impact on the end use.

Opportunities to influence waste then increasethrough the procurement stage, and thenagain through construction. Procurementpresents an opportunity to eliminate wasteat source, by working with subcontractors.Failing to get their input could result inproblems being designed in rather thanout. In addition, the construction phase iswhen site management arrangements mustbe sufficiently robust to minimise andmonitor waste.

Some opportunities to reduce waste mayrequire more effort than others. Someopportunities simply involve minor changes or‘tweaks’ to the design or construction process.Some of the larger opportunities may require alittle more effort to achieve as they may involvemore fundamental changes, either to the wayin which the design is produced, or to thedesign itself.

For example, a discreet change to a designwhich results in reduced off-cuts could berelatively easy to achieve. Conversely,establishing a robust process of wastereviews by the design team on an ongoingbasis may require more effort. These requireearlier consideration and a more holisticapproach, but with a potentially larger andmore lasting impact.

Roles and ResponsibilitiesEffective waste minimisation requires a teamapproach. All members of the design andconstruction team can contribute to wasteminimisation either directly or indirectly bysupporting others in the supply chain. Ofparticular importance in this team is theclient who sets the agenda for the project.

Virtually all organisations involved in theconstruction process have an influence on theway waste is generated and handled. Table 6.1highlights how each of the key stakeholderscan influence waste.

6.0 Waste Minimisation opportunities


By elevating wasteup the agenda, realreductions in wastecan be achieved.

Figure 6.1: All stakeholders can influencewaste

Client

Sub-contractors

Wastereduction

Contractors Designers


ClientSetting a waste minimisation agenda earlyin the project provides a clear mandateto all parties that good practice is to beimplemented at every stage of the project.In particular, using the following form ofwords in the project brief will ensure thatwaste (including waste management) isaddressed throughout. The client is alsoresponsible for ensuring all parties arefulfilling their roles in the effort toreduce waste.

‘In respect of the efficient use of materials,our aim is to minimise the consumption offinite natural resources and to minimise thequantity of waste being sent to landfill sites.Therefore, as general design principles,we seek the following where commerciallyviable (in accordance with the wastehierarchy):� efficient design and stock control

to minimise the use and waste ofmaterials;

� reuse and refurbishment of existinginfrastructure;

� use of reclaimed products andmaterials;

� use of renewable materials from legaland sustainable sources (such as timberwith appropriate certification);

� waste minimisation on site;� recycling of construction, demolition

and excavation waste; and� procurement of products and materials

with good practice levels of recycledcontent (relative to other productsmeeting the same specification).

These objectives should be pursued whileavoiding adverse impact on cost, qualityor other requirements in this brief, andminimising transport (especially roadtransport of heavy materials) wherefeasible.’

DesignersFundamental design decisions about buildingform and shape can have dramatic effects onthe waste likely to be generated. At outlinedesign stage, the designer has a significantopportunity to influence the waste likely to begenerated – this includes the re-utilisationof existing building stock or materials. Inaddition, consideration of the constructionprocess at outline design stage can identifysubstantial opportunities to minimise waste(and associated costs) during construction.

As the design develops, opportunities toeliminate design waste must be identifiedand pursued. In addition, good designcoordination is required to ensure thatunnecessary changes and site modificationsare required. The designer should not workin isolation on this and should be robustlysupported by the client and contractor.

Table 6.1: Stakeholder and waste reduction opportunity matrix

Main Sub-Source of waste Client Designer contractor contractor Supplier

Demolition � �

Material from demolition/site clearance � � �

Temporary works � � �

Excavated materials � � �

Design changes � � �

Design decisions � �

Off-cuts � � �

Over ordering � � �

Damaged materials � � � �

Packaging � � �

Contaminationof ‘clean’ waste � � �

ContractorThe contractor’s main role is to develop theSite Waste Management Plan (SWMP). Thisfocuses upon site and should address bothwaste reduction and waste management.It is the contractor who sees where wasteis generated on site, in what quantity andwho should be able to support the designerduring the planning stages in looking forwaste within the design. Key to this is earlycontractor involvement.

Rather than just focusing upon a wastemanagement strategy, the contractorshould also identify a waste reductionstrategy by which the total quantity of wastewill be reduced. In particular, this strategyshould reflect the considerations and designdecisions taken earlier in response to wastereduction. The main contractor should alsolearn lessons for continuous improvementby gathering site waste data and comparingthese against benchmarks and targets. It isgood practice for a contractor to name anindividual who is responsible for thedevelopment of the SWMP.

SubcontractorThe subcontractor is the party that actuallyorders, and handles the materials. For thisreason the subcontractor has a large partto play in delivering the clients objectivesand should be engaged early in the wasteplanning process. In particular, the earliertheir involvement, the greater the impacttheir input may have. They must beencouraged and supported to do so.

Some trades are able to provide very focusedadvice. For example, dry-liners and flooringcontractors will be able to produce accurateestimates of materials required, and shouldbe able to identify exactly what waste willbe generated – in turn they will be able torecommend ways to reduce this waste.This information should be fed to the maincontractor so that it can be incorporated inthe SWMP.

On completion, the subcontractor shouldprovide accurate data on the actual level ofwastage and useful feedback on why wastewas generated and how it could be reduced.


Guidance Note 1: Communication


OverviewCentral to waste minimisation iscommunication. Effective communicationduring design and construction has a directimpact on the type and quantity of waste thatis produced on site.

Reducing waste should not be difficult on mostprojects – what is more challenging is that toachieve these reductions project teams needto think about waste differently. Waste needsto be raised up the agenda so that whendesign decisions are made, or logisticsstrategies developed, the impact upon wasteis considered and action is taken. All teammembers need to understand and share acommon goal – that of waste minimisation.Only by working together will this be possible.

On a wider scale, there is a need forinformation dissemination between projectsand industry including lessons learnt andnew or alternative approaches to wasteminimisation.

Below are some of the key opportunitiesfor reducing waste though communication.

1.1 Project requirementsSetting project requirements is a ‘hard’communication mechanism to ensure wasteminimisation is considered throughout theprocurement process.

1.1.1 Client policyThe client can set an overarchingenvironmental or procurement policyrequirement to signal intention and providea mandate for action in materials efficiency.The following statement is a model clientpolicy:

1.1.2 Project briefThe catalyst to waste reduction is the client.As part of the pre-project brief and outlineconcept, the client needs to establish thatwaste is an important issue and challengethe project team to deliver a project thatuses materials efficiently. This can beachieved through:

requiring the design team to identify andreduce waste wherever possible; andrequiring the main contractor to developand implement a SWMP which includeswaste minimisation measures.

Model forms of words for project briefingcan be found in WRAP, Achieving effectiveWaste Minimisation.

1.1.3 AppointmentsThe involvement of stakeholders with theknowledge, capabilities and willingnessto reduce construction waste is essential.Second to client buy-in, appointment ofappropriate designers and contractorsis a key requirement to fulfil the wasteminimisation agenda. Both project briefingand setting robust contractual requirementsare ‘hard’ communication mechanisms whichensure the appropriate approach to wasteminimisation is taken.

For example, reviewing temporary worksthrough an independent buildability reviewas part of the tender assessment stage canensure that waste minimisation is consideredbefore the contract award.

‘As part of its commitment to sustainableconstruction, [Organisation name] aims toimprove its efficiency in the use of materialresources. One targeted outcome is tocontinuously reduce the quantity of wastearising and increase the recovery ofmaterials for reuse and recycling on allconstruction projects. Therefore, in itsprocurement, [Organisation name] will setrequirements for its projects to incorporategood practice Waste Minimisationtechniques and to plan and implement goodpractice waste management and recoveryin accordance with WRAP guidance.’

The key to wastereduction is achange in mindset,rather than off theshelf solutions.


Procurement opportunities

Logistics opportunities


Project timeline

• Project requirements • Ways of working

Model forms of words which may be used inboth the appointment of a designer and of acontractor can be found in WRAP, Achievingeffective Waste Minimisation. Specific wordingis included to address the design and buildprocurement route.

1.2 Waste minimisation targets,clauses andmonitoringWaste minimisation can be encouraged bysetting contract requirements for wastereduction linked to specific targets. Given adefined means of monitoring performance thiscan be a very powerful method of stimulatingchange. This ensures that the Contractor isaware of what is expected by the Client andprovides a benchmark for comparison.

Setting targets for waste reduction can be aneffective incentive to improve. However, thisrequires careful consideration. For example,if the contractor has an incentive to reducewaste, is a realistic benchmark available fromwhich an improvement can be measured?Also, does the contractor have absolutecontrol over the waste quantities – recognisingthe design is a major contributing factor?

Data on waste minimisation is limited andevidence to show that incentive clauses workis scarce. For this reason, it is recommendedthat targets are only set for defined elementsof work where good data exists. To obtain thisdata it may be necessary to begin recordinga baseline of performance from whichimprovement targets can be agreed, vianegotiation, with contractors and/orsubcontractors.

1.3 Soft communication and waysof workingImproving the ‘soft’ communication betweendesign teams and the contracting teamsis essential to reduce waste. Below aresome specific actions that can be takento improve this.

1.3.1 EngagementThere are some simple steps that the projectteam can take to ensure that waste is elevatedup the agenda and is addressed robustly. Onesolution involves adding a waste item to teammeeting agendas. If waste is discussed as partof the general project development (whetherduring design, procurement, or in sitemeetings) then it cannot be ignored. Just fiveminutes at each meeting would ensure that itstays within the scope of the project, and doesnot become a ‘sustainability bolt-on’.

Another aspect is partnering across thedesign and construction team. Contractorsand subcontractors have first hand knowledgeof what causes waste and how this could bereduced. Sharing the information withdesigners is essential. In addition, thinkingabout logistical and procurement issues earlyon ensures that decisions are not made whichlater compromise waste reduction initiatives.A key part of this is therefore earlyengagement of contractors so that theymay contribute to early waste identificationand decision making.

One specific solution that could be used is tohold discreet waste workshops. These wouldbe an effective method of sharing ideas in anopen and neutral forum. Again, giving wastesuch a platform and encouraging participationis likely to generate useful ideas. It alsoreinforces the message that waste is not justan issue for contractors, but for everyone.



1.3.2 WorkshopsHolding structured waste minimisationworkshops can provide a useful forum to focuson and target waste. Bringing together eitherthe design teammembers or if possible thedesign and contracting teams (depending uponthe stage of the project), opportunities toreduce waste can be explored. The benefit ofthis workshop approach is that ideas can betabled in an open and neutral environmentwhereby, even if they are not pursued thencan at least be considered. Effective wasteminimisation can require some creativethinking whereby more is achieved with less.Trade contractors in particular should be ableto provide specific and practical solutions.

1.3.3 Stakeholder awareness and knowledgeTeammembers should have an awarenessof waste reduction opportunities. Thereare few ‘expert waste minimisers’; instead,all members of the design team shouldunderstand that waste is an importantissue and recognise that they do have theability to influence the amount of wastegenerated. For example, the Designer shouldask, ‘is there a better system’ and look foralternatives that better meet the project aims.Similarly, contractors should evaluate wherewaste is occurring and commit to findingwaste reducing solutions.

1.4 ConclusionUnderpinning all of the ‘hard’ wasteminimisation solutions is a need for a generalcultural change within the industry, wherebywaste is discussed and actively targetedthroughout construction. Fundamental tothis is open communication where innovativesolutions are actively encouraged totarget waste.

Things to consider:The project brief should have clear requirementsto minimise (and manage) waste effectively.Ensure consultants and contractors havecontractual obligations to participate in wastereduction.Waste minimisation targets must be realisticwhilst still providing a foundation forimprovement.

Encourage project teams to think about anddiscuss waste minimisation options – eitheras part of regular meetings or within definedwaste minimisation workshops.Use contractors and subcontractor knowledgeearly in projects to maximise their input.A thorough review of options may require higherdesigner time input at early project stages.These additional time costs are likely to berecouped during later stages of the project.

Guidance Note 2:Design

OverviewDesign presents some the greatestopportunities to influence waste. The designof a building determines the size, shape andmaterials required. The principle of wasteminimisation in design involves ‘designingout waste’ or the use of efficient design andplanning to reduce the quantity of wastebefore it arises on site.

Getting the design right – i.e. ensuring thatwasteful elements are addressed – means thatthe contractor’s role is much simpler. Failureto think about waste in design means that thecontractor is often unable to reduce some ofthe wasteful elements which have been‘locked in’ by the designer.

There are a wide range of opportunitiesto reduce waste in design. This sectionintroduces the key opportunities splitbetween the design process and thedesign solution, outlined in Figure 2.1 below.


What is Design?This guide draws a distinction between the design process and the designsolution. Opportunities to reduce waste can be found in both.

The design process is the process by which the design is produced. Thisincludes briefings, communication, teammeetings and design freezes.Waste reduction opportunities involve changing the designers (and thewider project teams) approach to waste throughout this process.The design as it is drawn and the specific design decisions that are taken.Opportunities to reduce waste come from changing the drawn solutionfrom one option to another.

Figure 2.1: Opportunities to reduce waste can be found in both the design process and the design itself





Project timeline

• The design process• The design

Milestone reviews

Design process

Design solutions

Checklists

Early design Detailed designPre-design

Design decisions• Demolition options• On-site use of materials• Ground and enabling works• Design for deconstruction

and adaptability

• Standardisation of building form, layout and materials

• Design for material dimensions• MMC

Waste minimisation strategy• Engagement/waste on the agenda• Preventing design change• Design for change

• Design for site conditions• Site Waste Management Plan (SWMP)

Appointment


2.1 The design processThis section outlines practical steps thatcan be taken during the development of thedesign. By thinking about waste throughoutthe design process, it is likely thatopportunities to reduce waste will beidentified. Whilst this may seem like commonsense, waste is rarely high on the agenda(if at all) during design. The result is thatdesign decisions are made which can ‘lock’a quantity of waste into a project. Followingare some suggestions which will help ‘unlock’this waste.

2.1.1 AppointmentsEffective waste minimisation requires ateam of consultants and contractors whoare committed to waste reduction. It willbe almost impossible to make changes ifconsultants are entrenched in their usualmethod of working.

An open approach to design is required,whereby designers are willing to challengetheir own designs (and have them challengedby others) to try to improve the overallsustainability of the scheme – in thisinstance by challenging design decisionswhich contribute to waste.

Underpinning this is a need for contractualappointments which have obligations toreduce waste. Sample wording which canbe used in the appointment of designerscan be found in WRAP, Achieving effectiveWaste Minimisation.

2.1.2 Waste minimisation strategyHaving committed to reducing waste andhaving identified ways to do it, it is importantthat these discussions and actions arerecorded. What is needed is a wasteminimisation strategy. It is likely that this willbe linked into the Site Waste ManagementPlan (SWMP). However, often the developmentof the SWMP begins with the appointment ofa contractor. If decisions on waste are beingmade before this point then they should becaptured and then bolted into the SWMPon appointment of a contractor. A wasteminimisation strategy can be a useful toolto capture decisions taken to reduce waste.

A waste minimisation strategy shouldcapture decisions relating specifically tothe minimisation of waste. Because manyopportunities exist during design this maybe developed initially by the Architect. Onappointment of a contractor the responsibilityto own and maintain this strategy could bepassed over, enabling it to be linked intothe SWMP.

A waste minimisation strategy should identifythe following:

where waste arises in design,procurement and logistics;waste reduction opportunities andtargets;an approach to communicate wasteminimisation solutions to projectstakeholders;an approach to monitor theirimplementation throughout the projectlifecycle; andmechanisms to feedback lessons learntto the design team.

The role of the SWMP in designA Site Waste Management Plan should be developed from the pre-design stage by an appointed memberof the design team and passed on to the contractor. SWMPs often focus exclusively upon site activitiesand how waste streams can be recycled. To get the most out of a SWMP it should also address wasteminimisation issues.If developed by a contractor, it is important that the SWMP looks back to design and is used to captureall actions and decisions made by the design team which affect waste. It is crucial that these arecarried through and maximised by the contractor on site.At the end of a project, the SWMP should be used as a mechanism for feeding back lessons learntto the design team.

2.1.3 Communication throughoutthe design processThose opportunities to reduce waste identifiedin the communication section are of particularimportance during the development of thedesign. In particular, designers should beencouraged to:

engage with contractors and theirsubcontractors;commit to the development of a wasteminimisation strategy (where the SWMPis not being developed);put waste on the agenda at design teammeetings so that it can be discussedopenly; andhold waste minimisation workshopsto specifically target areas of waste.

2.1.4 ChangemanagementChanges to design and construction can occurat any stage of a project and regularly result inincreased waste due to completed work havingto be modified. Avoiding change, or at leastmanaging the change process effectively, isan important aspect of waste minimisation.

Below are some recommendations which willhelp reduce the impact or likelihood of designchanges.

Design Freezes – Freezing designs atcritical milestones can help to ensure thatprevious decisions are not revisited andgood work is not undone unnecessarily.Designers do face difficulties in limitingdesign changes due to client or sitepressures. However, the issue of wasteand sustainability should add strengthto the design freeze logic.

Design for change – Successful wasteminimisation can be achieved by usingdesigns that accommodate flexibility ofmaterials’ usage. Consider materials thatcan be used for more than one purpose

and minimising the range of materialsused to accommodate change in materialusage. For example – to provide flexibilityon site, consider limiting the range ofmaterials used so that there is flexibilityto use materials in different areas.

2.1.5 Preventing the need for changeClearly defined objectives from the client onwhat the design is required to achieve canhelp prevent changes being required due tomisunderstandings. A lack of awareness mayresult in changes to the design having to bemade later on in the contract. If changes areabsolutely necessary then the consequencesof these changes upon other aspects of thework should be carefully considered. Earlycontractor involvement can help identify whereconflict may arise, and if change is necessary,the best way of performing such alterations.Regular monitoring during construction toensure that work undertaken is to the requiredstandard can prevent changes being neededonce the construction is finished.

2.1.6 Design with existing resourcesWhere the site has a stock of materials thatcan be used (aggregates, reclaimed materials,existing buildings, services or roads) thedesigner should employ forward thinking andconsider how these may be accommodatedinto the new design. Often creative reuse ofexisting elements can positively contributeto the finished building, whether as anarchitectural statement or simply asengineering fill. For more information pleasesee WRAP, The efficient use of materials inregeneration projects.

2.1.7 Designing for site conditionsSite conditions should be adequatelyconsidered during the design phase. Whereit is known that the site will face particularconstraints which may impact on waste, thenthe design should accommodate strategiesto manage this.

For example, if the site is extremelytight and the chance of materials damagesubsequently increased then the potentialfor offsite manufacture could be considered.Also, if the site is known to suffer poorweather, designing the works so thatmaterials will be protected makes sense.For more information, please see WRAP,Achieving good practice Waste Minimisationand Management.


Figure 2.2: Comparison of a simple building (i.e. cube) witha complex building

For example, a squarebox structure shouldhave less waste thana complex structure.Almost all interfacesrequire materials tobe cut, and every cutresults in waste.


2.2 Design SolutionsThis section contains practical designsolutions that can help reduce waste. Itfollows a value engineering logic wherebythe intention will always be to deliver thesame (or more) for less – in this instance,less waste. Reducing waste is an effectiveway to add value because it is so stronglylinked to cost savings. Thus, the adoptionof a value engineering approach to designcan result in a range of project benefitsincluding waste reduction.

2.2.1 FundamentalsFundamental design decisions, such aswhether to demolish an existing facility ornot, will have the greatest impact on waste.The industry is already seeing designs beingradically adapted to address issues such asenergy efficiency and water consumption.It is at concept stage where the greatestopportunities lie and if clients are seriousabout avoiding waste then the whole approachto development can be modified to reducewaste (and cost).

The shape and layout of a building thereforehave large impacts on waste. This does notmean that all buildings should be designedas cubes but that designers should recognisewhere they are adding both cost and wasteinto a project. Complex interfaces can oftenbe simplified with low impact on form andfunction. For example, a bespoke design canstill design for standard material dimensionsor simplify material choice. This thinking willbe elaborated upon in the following sections.

Case study 2.1

Recycling and reuse of trench arisings – Clyde Street, GlasgowWater and gas capital and maintenance trench works generate around4.8 million tonnes of arisings across the UK, equivalent to 4.5% of the nationalconstruction, demolition and excavation wastes. Specific provision is givenfor the use of recycled aggregates and hydraulically bound materials, andreuse of trench arisings, within the second edition of the specification forthe reinstatement of openings in highways (SROH), Highway Authoritiesand Utilities Committee (HAUC, 2002).

Around 3,900 tonnes of trench arisings were excavated during thereplacement of a gas main at Clyde Street, Glasgow. 50% of the trencharisings were recovered and recycled for use as sub-base and pipe bedding.The benefits of this recycling operation were direct cost savings associatedwith recycling versus landfill and material purchase costs and reducedhaulage (due to proximity of the recycling centre). Reduced transportationalso had other indirect benefits including reduced air emissions, noise andtraffic on roads. Transporting to a local site also resulted in few delays dueto faster truck turnaround.

Increasing the amounts of recycled materials within their reinstatementworks was beneficial to the contractor achieving and maintaining theirISO 14001 accreditation.

For more information please see WRAP, Recycled and stabilised materialsin trench reinstatement and www.aggregain.org.uk

Case study 2.2

Recycling demolition waste at Barts and The London HospitalThe Barts and the London NHS Trust commissioned Skanska Innisfreeto manage and redevelop the St Bartholomew’s Hospital and The RoyalHospital. Keltbray was appointed as the demolition and recycling contractorfor the works. This is the largest PFI healthcare scheme in the UK estimatedat a value of £1 billion to include the design, demolition, construction andsome refurbishment of the two sites covering a total area of 270,000 m2.

A recycling rate of 93% for the works surpassed both the client’s original60% target and the extended 85% demolition target.

The attainment of this high recycling rate was attributed to good workingrelationships, partnership and trust, early contractor involvement to developcommon goals between project partners, contractual agreements, agreedsustainability objectives and technical experience.

Things to consider:Ensure designers’ appointments makereference to waste minimisation.Work with contractors and subcontractorsto identify solutions.Develop a waste minimisation strategy.Put waste on the agenda.Ensure that designs are frozen and thatchanges are subsequently avoided whereverpossible.Incorporate existing ‘waste’ materials on siteinto the design.Consider the impacts of the site on the wastegenerated.

2.2.2 On-site reuse of materialsThe reuse and recycling of materials on site,which would otherwise need to be disposedof, will reduce the amount of waste going tolandfill and help lower costs.

Not only can demolition materials beprocessed for aggregates and fill materials;designers should also seek to incorporateother materials such as reclaimed bricks,steel sections, salvageable timbers, etc.Incorporating these into design will againhelp to reduce cost and reduce waste. Wherethese can’t be used they can often be sold forreuse elsewhere.

Wherematerials are reused, it is importantthat they are reused at their highest value.For example, recycled concrete aggregates(RCA) can be used as low grade fill materials,but this material also has excellentperformance qualities whichmake it an idealaggregate substitute. It may therefore be betterpractice to use RCA as a high grade aggregateand import lower grade fill where this isrequired. (For additional information on thereuse of aggregates, visit theWRAP aggregatesweb-portal at www.AggRegain.co.uk).

Designers should note that recycledmaterials are not inferior and can meet thesame specifications as primary materials.Every opportunity should be sought touse these in the project, whether they beprocessed aggregates or reused elementssuch as steels, timbers, bricks or blocks.Early contractor input and clear lines ofcommunication from site to the designtable will ensure all possibilities arediscussed and made a reality where feasible.

Many of these decisions regarding the reuseof materials are recurrent in regenerationprojects. For information please see WRAP,The efficient use of materials in regenerationprojects.

2.2.3 Ground works and enabling worksGround works and enabling works offer majoropportunities to eliminate waste being sentoff site and achieve cost savings. This canbe achieved through innovative constructionsolutions that reduce the need to excavate,positively utilise site won materials andreduce temporary works. See Table 2.1.

2.2.4 Design for deconstructionand adaptabilityWhen developing the design, it is importantto consider the end of life potential of thebuilding. If it can be designed to be adaptablefor a variety of purposes, the life span of thebuilding may increase. Conversely, if thedesign considers future deconstruction,this can facilitate the reuse and recoveryof building materials. For further guidance,please see CIRIA, Design for deconstruction,principles of design to facilitate reuse andrecycling and the SEDA website onwww.seda2.org/dfd/index.htm

2.2.5 Standardisation of building formand layoutRepetition of design, either within a buildingor across a range of buildings reduces wasteby reducing the number of variables in theconstruction. Standardising layouts introducescommon elements which are repeated, sooperatives are able to refine their processes,such as reusing formwork. Thus, a designshould be selected that incorporatesstandardisation of design details, withrepeatability of the construction processand reduced bespoke detail.


Cut and fill optimisation Careful cut and fill analysis can ensure groundexcavated from cuttings can be used as fill materialelsewhere in the project (e.g. within embankments),no waste is sent to landfill and there is no need toimport fill. This can avoid the need for major truckmovements to and from site with a positive impacton the carbon footprint.An optimum cut and fill balance can be achieved byincluding a degree of flexibility in the design to allowfor site issues.It is also possible to use excess fill material in otherprojects and import materials from other sites.

Ground improvement Reinforced earth techniques can be used as antechniques alternative to reinforced concrete retaining walls and

can help to make use of site won materials, asopposed to creating a need for imported materials.The need to excavate and remove unsuitable groundcan be reduced by stabilisation techniques such aspreloading, soil nailing and piling.

Table 2.1: Ground and enabling works


Again, standardisation should not equateto ‘plain’ architecture, but instead shouldbe used to get more, for less (less wasteand less cost).

2.2.6 Standardisation of buildingmaterialsNot only can the building form be standardised,but so can the use of materials. For example,limiting the number of cladding solutionsshould mean that this limited range ofmaterials can be usedmore efficiently(i.e. less off-cuts).

The simplification of material choice canincrease opportunities for the use of off-cutsand surplus materials therefore reduce theneed for its disposal as waste. For example,rationalising the number of concrete mixescan reduce the need for expensive part-loadsor wastage due to over-ordering andassociated disposal costs. Concrete which issurplus to requirements for a particular pourcan be used in other parts of the concreteworks having the same specified mix. Thus,it is necessary from the outline design stage toidentify areas where common material typescan be applied and incorporated within thedesign and specification. In the programmingof construction, works should be planned sothat elements with the same material typeare either constructed at the same time ora provision is made for storage and later useof the surplus material.

2.2.7 Designing to material dimensionsDesigners have the ability to design buildings tofit the dimensions of thematerials that will beused. Wall dimensions can be designed aroundstandardmanufactured plasterboard sizes orflooring layouts may be rearranged to fit themodular size of carpet tiles. For example, ifplasterboard is to be used and the standardwidth is 1,200mm, and the room in which it isto be fitted is 4,500mm x 4,500mm, then at least300mmwastage of material due to offcuts oneach wall will ensue. This also applies toceiling heights.

This is a difficult area to get right as alteringone dimension will probably impact on severalothers. For this reason this is an opportunityto be aware of and, when in doubt, it is worthchecking with manufacturers about thestandard dimensions of their materials.

Conversely, a standard unit requirementof the design can be clearly defined andstandardised so to design in repetition oftasks. It may be possible for the supplier ormanufacturer to then provide products thatmeet the dimensions and fittings required.For example, plasterboards may be orderedpre-cut to negate the need for site cutting.

Again, this is a cost issue as reducing theneed for site cutting significantly speedsconstruction and reduces the waste. Accuratedesign information and drawings in electronicformat can also reduce over-ordering, off-cutwaste and reworking. More information onopportunities for waste minimisation inprocurement can be found in Guidance Note 3:Procurement or in WRAP, Reducing materialwastage in construction onwww.wrap.org.uk/construction

2.2.8 Modern Methods of Construction (MMC)The method of construction used has adirect impact on the type and quantity of wasteproduced onsite. Site cutting of materials isinefficient and is the primary source of wastein construction. Waste is also produced whenmaterials get damaged or become un-useable.

Selecting MMCs that eliminate or reduce therequirement for site cutting and handling ofmaterials can have dramatic effects on waste2.Offsite manufacture has been shown to reducewaste by up to 90% (volumetric buildingsystems versus traditional). The decisionto use offsite construction is often cost led,determined by a critical number of units.Rarely is the cost of waste considered in thisequation, however if waste costs were reducedby 90%, the threshold for using offsiteconstruction could drop dramatically.

Plasterboard in residential developmentPlasterboard is a key waste material which, onhigh-rise apartment schemes, can account foras much as 35% of total waste arisings. Themain causes of plasterboard waste are damageon site and excessive cut offs from whole boards.A project manager from a leading house buildernoted:‘Plasterboard off-cuts are a significant wastestream. It seems to be industry practice to usea new board to cut a small piece and then tothrow the remainder of the perfectly good boardin the skip. Offsite fabrication or room sizestandardisation would reduce or eliminate this.’

2 The termmodern methods of construction is used in preference to offsite manufacturing (OSM) as the former also includes several important new types of constructionmethods that involve some element of fabrication onsite.

Figure 2.3: Levels of site waste reduced usingMMC compared to equivalent traditionalconstruction methods

Figures are not indications of the levels ofcontribution to total waste reduction.

For example, the use of precast concreteunits in favour of in situ concrete will reduceconcrete wastage and have the added benefitsof faster construction time, less weatherdependence and assured material quality.Furthermore, any waste that is generatedoff site is often used in closed loop recyclingactivities due to its clean and consistentquality.

Thus, designing for the preferential use ofoffsite modular units also allows for thereduction in onsite waste. Off-cuts areeliminated at the construction site and ifhandled correctly, onsite breakages arereduced as modular units are often moreresistant to damage. Manufacturers canalso produce modular construction setsthat are made to measure with the piecesnumbered for assembly, so that there is noover-ordering and wasting of materials.

Another example includes plasterboard.Traditional plasterboard can create abortivework and reworking due to the need forcutting and onsite damage. Plasterboardalso generates more waste from the on-siteapplication of plaster finishing coats. Otherprefabricated boards such as Fermacell arewaste reducing alternatives to plasterboardwhich require no wet plaster finish and canbe more impact resistant.

2.2.9 Modernmethods of constructionproduct groupsPrevious WRAP research has identified thefollowing MMC product groups as offeringpossible solutions to reducing waste levelson construction sites over the short tomedium term:

Volumetric modularVolumetric building systems are the ultimatein offsite manufacturing technology and theirsubstitution for traditional building methodstypically leads to a virtual elimination of allwastage bar excavation spoil for groundpreparation. Wastage streams that arereduced or eliminated include roof andexternal wall insulation, roof tiling, brick andblockwork, drylining, onsite cladding and allassociated packaging. The technology is wellestablished and there are new developmentsin high-volume production, notably at Corus’Deeside factory.

Pre-assembled volumetric modular buildingsare defined as including offsite manufacturedfully assembled three-dimensional units, ormodules, which are either used as ‘standalone’units or are combined, by linking on site toform a complex of units, or alternatively toform amodular building, consisting of severallinked and stacked units or modules withappropriate cladding features. Volumetricmodules may be stacked several storeys highdependent upon module construction and theneed for additional structural elements, etc.

The UK volumetric prefabricated buildingsmarket has experienced a period of significantexpansion with the total market in 2005estimated at over £500m at manufacturerssales prices. The market for volumetricmodular buildings has tended to be projectdriven. The majority of installations have beenbespoke, undertaken on a design & build basisby the manufacturer themselves.

The overall market is forecast to continueto grow reflecting further growth in arange of end-use sectors including singleliving/cellular accommodation, health,education, MoD, hotel/leisure, etc.

Waste reduction potential of MMC

Volumetric building system 70–90%Framing systems 40–70%Pods 40–50%Panel Systems 20–60%Other MMC 30–60%

Up to 90%!



Panellised modular building systemsKey features of panellised modular buildingsystems include:

External wall and roofing frames/panelsare factory assembled although thedegree to which other components(e.g. internal wall plastering, insulation,cladding) are factory fitted vary.

They form part of the building’s structure,i.e. are load bearing, although they dooften also form part of the envelope.However, many products are flexible tothe extent that they can be used as nonload-bearing applications.

These frames and panels are typicallydelivered to site in ‘flat-pack’ format,where they are subsequently liftedstraight into position onto the foundations.

Under this heading there three main types:

Timber frame and steel frame systemsThese MMC technologies are mainly used inhousing and to a lesser extent on high-riseapartment blocks and low-rise commercialapplications. They are displacing the use ofconcrete blockwork used for the constructionof external wall inner leafs and party walls andthe waste associated with this, i.e. broken anddiscarded blocks, unused mortar and theassociated packaging. Where pre-fitted withplasterboard there are also apparent wastesavings compared to the in-situ installationof plasterboard. The demand for thesetechnologies is growing fast, underpinnedby housing shortages, with public sectorspecification an important influence ondemand.

Wood based structural insulated panelsystems (SIPS) and structural insulatedroofing panels (SIRPS)SIPS are typically made from oriented strandboard (OSB) and differ from composite panelsin that they are load bearing. While the use ofSIPS has been well established in the USA,their use in the UK has to date largely beenrestricted to social housing. SIPS are mainlyused for external walls, roofs, floors, partywalls and roofing, the key end-useapplications to date being social and privatehousing, and to a lesser extent commercialbuildings and apartments, generally up tofour storeys high. SIPS can also be used onnon-structural applications such as infillpanels and as overcladding on existing

buildings. Their increased use woulddisplace traditional construction methodsand associated waste, notably insulationmaterials, brick and blockwork. A key barrierto a substantial increase in use over a shortperiod is the low UKmanufacturing capacity.

Where substituted for traditional construction,SIPS can contribute towards waste reductionas they do not require blockwork, either for thefoundations or for the inner leaf and thereforeno waste in the form of off-cuts, discardedor damaged blocks and there is no need forpallets and shrink-wrap packaging usedfor their transportation and on-site storage.Furthermore, no insulation needs to beinstalled on site and therefore there areneither off-cuts nor packaging in the formof pallets and plastic wrapping.

Currently the use of SIRPs has largely beenlimited to the Unipur Structural InsulationRoofing System, which is manufactured byUnilin in Belgium and supplied by MilbankRoofs. There is a wide arrange of roofcovering options.

Confidence in SIPS and SIRPS among clientsand specifiers has been bolstered by therecent award of BBA, BRE or British Standardcertification to several products on themarket.

Pre-cast structural panels and panellisedbuilding systemsPre-cast panel systems is the term usedto cover a range of structural pre-castconcrete panel systems, which are nowincreasingly being supplied as panellisedbuilding systems, the key areas of applicationbeing the external walls, party walls andsometimes the basement walls. There are anumber of proprietary systems now available.Some of these are centred on insulated panelswhile others are largely based on cross-walltechnology.

Structural wall panels on their own andpre-cast panellised building systems areused as fast-track substitutes for brick andblock, and blockwork & cladding/renderbuilding methods. The more basic optionsreplace the need for inner-leaf blockwork,mortar and more often than not internalwall plastering. Insulated panels negatethe need for insulation to be fitted onsiteand this eliminates insulation waste andthe associated packaging waste.

Prefabricated kitchen and bathroom podsThe growingmarket for prefabricated kitchenand bathroom pods is underpinned by demandin fast growing sectors of the single livingaccommodation (SLA) market which includesMoD garrisons, student residences, Key WorkerLiving and high-rise apartment blocks. Keywaste streams that are likely to be reducedusing pods include those generated throughthe interior fit-out of kitchens and bathrooms,plumbing off-cuts and cement and plaster.

Pods are discrete volumetric units that arefactory fitted with building services equipment,e.g. electrical circuitry, lighting and plumbing,etc, but which do not form part of the buildingenvelope. Bathroom and kitchen pods aretypically available in frames made eitherfrom concrete, steel or GRP. Concrete podsare typically load bearing structures that areoften installed into a building’s structuralconcrete framework. GRP and steel podsare either similarly installed onsite throughbeing lowered by crane into steel structuralframework or they are supplied direct tomodular building manufacturers to be fittedinside larger volumetric modules. As such, itis difficult to make a clear distinction betweenpods and volumetric modules.

Because pods are a well-established formof MMC, architects and contractors arenow comfortable with specifying pods overtraditional construction methods for cellularaccommodation.

Substitution of pods for traditional methodsfor constructing bathrooms and kitchens hasled to a reduction in several product wastestreams, notably:

pallets, cardboard packaging,shrink-wrap and banding used forsanitary ware, tiles, fittings, mirrorsand taps, ‘white goods’ for the kitchenand fitted kitchen components;damaged ceramic ware, floor and walltiles;damaged fitted kitchen units andincorrectly installed kitchen unitsrequiring reworking;less worktop off-cuts;plastic bags for plumbing componentsand lighting components;paper bags for tile grouting mixes;tins and plastic pots for paint andadhesives; andunused grouting and mastics.

The only waste generated from the installationof pods themselves is the shrink-wrap and thecardboard packaging for door units as thepackaging.

Building Envelope ComponentsIncluded in this section are prefabricatedcomponents that form part of the buildingenvelope, i.e. the external façade and theroofing. Three major product groups include:

Composite panelsComposite panels or insulated or ‘sandwich’panels typically comprise of two sheets with acore material sandwiched between the sheetinner surfaces. These panels used for wallsand roofing are mostly profiled steel productsused on commercial and industrialapplications, although there are newerproducts made from other materials such asconcrete and GRP suitable for residential use.Although current uptake levels of steel profiledcomposite panels are quite high, marketpenetration is still way below the maximum.It is likely that they will further displacesite-assembled twin wall systems, whileenergy saving regulations will lead to aphasing out of single steel cladding on manyapplications. The main waste generated formonsite assembly of twin-wall systems is wasteinsulation material. Roof panel systems thatarrive on site with simulated tile effects couldlead to a reduction in time offcuts andpackaging waste.

Composite panels are an alternative forsite-assembled twin-skin systems and singlesheet products. Waste savings include that forthe insulation core of twin wall systems whichare typically supplied in standard sizes andthus produce off-cuts. Composite panels arealso generally more robust and reduce wastethrough damage.

Pre-cast concrete claddingThis product covers both load-bearing andnon-loading bearing panels made frompre-cast concrete and used for externalwall cladding. This is typically manufactured,supplied and installed under bespoke supplyand fix contracts. They are high-value productsdesigned for prestigious buildings such asacute hospitals, corporate headquarters,government buildings and large-scaleshopping malls.



Pre-cast panels are preferable to in-situcladding where site space and time is limitedas in-situ cladding requires a large area tostore materials, lay down the formworkand mix concrete and fit the insulation.Factory-made cladding saves waste oversite-assembled cladding as there is not needfor plywood formwork, scaffolding or for ‘wet’trades, all of which typically generatesignificant levels of waste.

Light steel framing (LSF) systemsThese are one of the more recentdevelopments of MMC, used for buildingfaçade construction compromising insulation,drylining and external wall cladding, largelyas an alternative to traditional brick andblock construction for apartment blocksand non-residential buildings of usuallyup to six storeys.

LSF systems are broadly split between ‘stick’systems that are site-assembled and framesystems manufactured offsite. Frames arefurther split between open and closed types.They are typically either supplied direct tovolumetric building manufacturers or to sitewhere they can be used as infill panels or forcontinuous façade construction.

Closed frame systems are the new productson the market currently only supplied byKingspan Offsite. Although uptake levelsare currently low, there is considerablepotential to displace onsite cladding/façadeinstallation. A high level of uptake could, intheory, lead to lower levels of site-generatedwaste from insulation, drylining and claddingmaterial off-cuts.

Where substituting open frame systems fortraditional methods of façade construction i.e.brick and blockwork or blockwork and in-situcladding or render – the main material wastesavings are the elimination of block wasteand associated packaging and the reduction/elimination of brick waste, unused render andcladding off-cuts. Closed panel systems cancontribute towards waste reduction typicallyarising from delivery, site storage andinstallation of separate insulation, dryliningand cladding or render elements.

MMC structural pre-cast concretebuilding componentsThis section includes structural pre-castcomponents that are not used in theconstruction of the building envelopeincluding both standard products andproprietary systems.

Pre-cast hollow-core flooringThere are indications of an increase in thespecification of hollow-core flooring on groundfloors and second floors on residential andcommercial applications, in substitutionfor in-situ concrete flooring and timberflooring. In-situ concrete flooring typicallyrequires a large amount of formwork, whilein-situ timber flooring generates packagingwaste and offcuts material.

Hollow-core slabs require no packagingand thus produce no packaging waste.

Beam and block flooringThis is typically used for ground floorconstruction as an alternative to in-situready mix concrete used with formwork.Some systems such as Jetfloor fromHanson Building Products are used inpreference to solid concrete floors onclay soil.

Tunnel form constructionTunnel form construction is a new formof MMC in the UK but is well established inseveral other Western European countries.It is specifically used for the constructionof large-scale cellular buildings with keyend-use applications including studentaccommodation, standardised apartmentblocks and terraced housing, prisons, hotelsand barracks. It is essentially a formworksystem that allows constructors to mouldonsite the external wall, floor and party wallelements simultaneously and is commonlyused in conjunction with other types ofprefabricated elements such as pods andpre-cast cladding. Although it is not an MMCproduct it is recognised as one of the mostsignificant of the new MMC. The substitutionof TFC for traditional building products haseliminated the need for plywood formworkand shuttering.

Insulating concrete formworkInsulating concrete formwork has beendeveloped as an alternative to the traditionalmethod of setting ready mix concrete orconcrete slabs and mortar inside a plywoodframe. This is a factory made formworksystem comprising twin wall expandedpolystyrene (EPS) blocks and panels, whichare assembled to create the walls of abuilding. Ready mix concrete is subsequentlypoured into the cavity gap. The EPS remainsin place to act as the external wall insulation.This is a relatively new system to the UKmarket but it has been used on housing.The substitution of ICF for traditional buildingproducts has eliminated the need for plywoodformwork and shuttering. ICF also eliminatesthe need for the in-situ installation ofinsulation and associated packaging.

Thin joint masonry (TJM)Accurately-dimensioned aircrete blocks withspecially developed Thin-Joint mortar whichenables walls to be built rapidly without havingto wait the conventional 24 hours for mortar toset before loading can be applied. The use ofTJM has mostly replaced beam and blockworkat ground level on housing developments. A keybenefit of TJM blocks is that they can be easilyand accurately cut, sawn and worked on site.The precision cutting of blocks for use with thinlayer mortar allows greater utilisation of theblocks, which can substantially reduce sitewastage. On average, off-cuts waste from theinstallation of standard aircrete blocks is ashigh as 10% but with TJM blocks, off-cutswaste is generally less than 3%. The otherkey waste reduction is the mortar. Thin layermortar is a pre-mixed cement based productthat only requires adding water to make aneasily applied mortar. The depth of the mortarcan be reduced from at least 10mm to 3mmor less. The substitution of TJM for traditionalblock construction reduces mortar usage bysome 70%.

2.3 Checklists for addressingconstruction waste in designThe following checklists can be used toaddress construction waste during thedesign process and in formulating the designsolution. Specific checklists are provided forthe client team, design team and contractorteam specifying potential issues to beaddressed, the actions required and arecord of whether/when these took place.

2.3.1 Client team checklistIn table 2.2 on the next page, the text in italicsprovides an example of the type of actionrequired by the client team. These actionsshould be considered by the stakeholders andappropriate action recorded for each specificelement of the construction project. Additionallines, issues and actions can be added whereappropriate.

2.3.2 Design team checklist for addressingconstruction waste in designThe text in italics provides an example of thetype of action required by the design team.These actions should be considered by thestakeholders and appropriate action recordedfor each specific element of the constructionproject. Additional lines, issues and actionscan be added where appropriate.

2.3.3 Constructor team checklist foraddressing construction waste in designThe text in italics provides an example ofthe type of action required by the constructorteam. These actions should be consideredby the stakeholders and appropriate actionrecorded for each specific element of theconstruction project. Additional lines, issuesand actions can be added where appropriate.



Table 2.2: Client team checklist addressing construction waste in design

Table 2.3: Design team checklist addressing construction waste in design

To download anyof the templates

on this page, click onthe adjacent page icon.

http://www.wrap.org.uk/document.rm?id=4960



Table 2.4: Constructor team checklist addressing construction waste in design

Things to consider:At the earliest stages of the project, thinkabout waste when concepts are considered.How complex does the building need to be?What materials are there available for reuseon site? How can these add to the architecturalstatement?What options are there to reduce soils andaggregate movements?

Consider the potential to standardisethe building form and/or materials.To what extent can the design accommodatethe standard dimensions of building materials?What are the opportunities to use off siteconstruction?

To downloadthe template



Guidance Note 3: Procurement


OverviewFar too often materials are brought to siteonly to then be wasted. The principle ofwaste minimisation in procurement involvesproducing accurate estimates of materialsrequired and then using these materialsmore efficiently.

The quantity of materials ordered is ofteninaccurate and unreliable and results inover ordering and material wastage. This isan area where costs can be saved throughbuying better. There is scope for waste (andits associated cost) to be accurately estimated,controlled and reduced during procurement.

This is primarily a subcontract issue as it isthe subcontractors who usually place ordersfor materials with suppliers. Subcontractorsshould use their expert onsite knowledge toproduce accurate and realistic estimates ofmaterial requirements and their associatedwaste. This highlights the importance of earlycontractor involvement and communicationstreams throughout the supply chain.

Subcontractors play an integral and essentialpart in the drive to reduce waste on projectsbut they must also be supported by clientsand main contractors.

3.1 Procurement solutionsSubcontractors can follow a procedureoutlined below to improve their materialsordering process. This process encouragessubcontractors to make robust and realisticallowances for their waste, gather data on howmuch waste they do generate, and then usethis information to improve their waste profile.

Figure 3.1 sets out how subcontractors canreduce waste by taking action in four stages.At each stage subcontractors can dosomething to reduce the waste they generate.The stages are:

planning;implementation;review; andimprovement.

Within each stage, subcontractors canmonitor material use and wastage rates withthe aid of a series of supporting checklists andproformas. Areas where the client and maincontractor can support the subcontractor indoing so are also included.

Case study 3.1

Retail developmentA retail development employed a subcontractor to carry out 2D and 3Dmodelling using PC software to compare drawings and eliminate clashesin the different drawings of the architects, engineers, and highways,building services, structural and sub-structural versions. Many errorsand inconsistencies were found. Although the clash detection exercisecost £100k to the client and designer, the overall savings were suggestedto be £2.5m

Planning

Client setstargets for waste

Main contractorprepares

Site WasteManagement Plan

Subcontractorestimates waste

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Implementation

Main contractorsand

subcontractorsreview waste

and take actionto minimise

andmanage waste

Review

Main contractorrequests final

waste informationfrom

subcontractors

Subcontractorscomplete

waste informationquestionnaires

Main contractorcoordinates dataand feeds back

to client

Improvement

Share lessonslearned

Promoteinnovation

Raiseawareness

Demonstratebetter financial

andenvironmental

results

1 2 3 4

Figure 3.1: Outline of how subcontractors can reduce waste by takingaction to in four stages

• Planning• Implementation• Review• Improvement





Project timeline

Users are encouraged to select, adapt anddevelop the most useful check-lists andproformas as ‘pull-out’ documents so thatthey can be integrated into the client’s/maincontractor’s/subcontractor’s own standardprocedures, thus supporting a drive forgreater materials efficiency. They should notbe followed rigidly but rather seen as simpletools that help to highlight the importantareas where effort should be directed.

3.1.1 PlanningThis stage involves the development of theSite Waste Management Plan (SWMP) by themain contractor, and also the developmentof waste estimates by subcontractors. Bybringing the subcontractors into the sitewaste management planning exercise, realreductions in waste can be realised, ratherthan merely planning to manage the wastestreams that will arise.

The main contractor should further developwaste management plan which contains thefollowing key features:

The DTI Site Waste Management Plan,Guidance for Construction Contractors andClients and subsequent guidance fromWRAPcontains proformas and checklists to supportthis. Linking procurement of subcontractpackages to the SWMP ensures that specialisttrade input is obtained and accurate figuresare used in the waste estimates for the project.Main contractors must therefore ensure that,where possible, subcontractors are engagedand challenged on the waste they are likely togenerate (see quantitative estimates overleaf).

By producing accurate estimates of thequantities of materials required and thewaste likely to be generated, contractorsand subcontractors will be able to managea process of waste reduction that willenable them to meet the waste targetsset for the project.

Accuracy of materials estimatesTo avoid over-ordering, subcontractors needto produce accurate estimates of the materialsthey require. To do this they need accurateinformation from which they can produce theirown take-off, converting project requirementsinto material allowances (i.e. converting m2 ofbrick wall into X number bricks).

For many trades the ‘take-off’ process canbe very accurate, especially where specialistestimating software is available. The mainproblem usually arises in subcontractorsbeing given insufficient or inadequateinformation. Design teams and maincontractors should therefore ensure thatsubcontractors receive the information theyneed. If it is not received then subcontractorsshould be encouraged to ask for it. Again, acollaborative approach is required. Materialestimates can be further improved throughusing more precise measuring tools such asbespoke digital estimating software based onCAD drawings.

The accuracy of material quantity estimatescan therefore be improved by:

ensuring when subcontractors are pricingprojects or placing orders for materialsthat the information used is up to date,accurate and in the correct format;undertaking site measurements wheredrawn information is not available, ornot sufficiently accurate; andusing specialist ‘take-off’ software.

The following checklist could help assessthe quality of the information available:

Accuracy of waste forecastBecause materials are cheap and labour isexpensive, a percentage ‘waste allowance’or contingency is added by subcontractorsto each package. Too often subcontractors

� Are the design and specificationscomplete and up to date?

� Are the drawings provided the latestissue?

� Is there any further informationrequired?

� Are the drawings available in a formatthat enables accurate scaling andprinting?

� waste targets as set by client;� an estimate of the waste to be generated

on site;� actions to reduce waste; and� actions to avoid waste going to landfill.


Planning

Client setstargets for waste

Main contractorprepares

Site WasteManagement Plan

Subcontractorestimates waste

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use arbitrary wastage allowances with littleconsideration of the project. They are oftengeneric approximations based on ‘historicaldata’ and are not project specific. This canlead to either the order of a surplus ofmaterials (usually entering the waste stream)or a materials shortfall (resulting in additionalcosts to purchase more materials).

Subcontractors should be encouraged todevelop amore accurate wastage allowancethat recognises two sources of waste. Whenthe design is fixed, some waste is then ‘locked’into the project. Materials off-cuts are in manycases unavoidable without revisiting thedesign. This therefore determines a fixedamount of waste. In addition to this, there isthen a quantity of accidental waste, comingfrom site damage, inefficient use of materials,installation errors or rework. This latter sourceof waste can be controlled whilst on site.

Therefore, waste allowances should recogniseboth these sources of waste and accuratelyreflect the characteristics of the project. Forexample, if the design teams have workedhard to reduce the off-cuts required, thensubcontractors should reflect this in theirwaste allowance (and in their tender price).

To achieve this streamlined approach tomaterials ordering, subcontractors needto collect data on their own performance.For example, asking questions like “Whatquantities of materials were required andhowmany have I ordered?” begins to focusthe mind on opportunities to improve. Thereis a weak understanding of wastage rates ata subcontractor level, suggesting that theindustry could be much more efficient bothwith its use of materials, but also leaner interms of project costs.

An accurate wastage allowance can thereforebe developed if:

better information is provided tosubcontractors;subcontractors understand the need foraccurate wastage allowances, drawinga distinction between design waste andaccidental damage;specialist ‘take-off’ software is used asappropriate; andsubcontractors record their own efficiencylevels on projects and use this data toinform their own tendering and orderingoperations.

The following actions can help thesubcontractor reduce waste by producingmore accurate estimates of the waste thatwill be generated:

Use CAD drawings – When measuringthe quantities of materials required(taking off), ensure that the drawingsare available in digital format so that theinformation extracted is accurate andto scale. By doing so, contractors,subcontractors and suppliers can haveaccess to the same information anderrors are avoided. This also allowssubcontractors to use electronic takeoff software (see below).

Use digital estimating software – Whencarrying out measurements, use softwaredesigned specifically for each particulartrade (if available). By doing so, accuratewaste estimates and more economicalsolutions can be achieved (i.e. it cansuggest how to lay carpet in the leastwasteful way, how much plasterboard isneed for a particular type of space etc).

Carry out site measurements – Moreaccurate estimates can sometimes beproduced if site measurements can becarried out. These are particularly usefulwhen drawn information is limited.

Identify causes of waste – Ensure thatall the causes of waste are identifiedat tender stage and develop mitigatingactions.

The following checklist could help assesswhat the causes of waste are. If the answeris ‘No’ to any of these questions, an actionfor improvement should be set:

� Is the tender documentation complete?� Is the design fixed and agreed?� Is the information provided clear?� Is adequate and safe storage available

onsite?� Is the workforce trained in waste

reduction and management?� Does the programme allow for the work

to be carried out with no interferencewith other trades?

The Quantitative estimate 1 and theQualitative checklist 1 on the following pageare designed to feed directly into the SWMPsuch that there is a visible cause and effectrelationship between subcontractors’estimates and main contractors’ actions.

Quantitative estimate 1When each subcontract trade develops aprice and/or orders materials, an allowancefor waste is made. Often this allowance isinaccurate or based upon qualitative notquantitative data. By accurately estimating thewaste likely to be generated from each of thekey trades, subcontractors can take measuresto reduce waste.

A simple proforma, see following page, shouldbe completed by all trades on the project thatgenerate waste. This should be compiled whenpreparing a firm price for the project so thatcost savings (or increases) can be reflected inthe package tender/negotiated sum.

Completing this table requires thesubcontractor to think in more detail aboutwhat and why wastes will be generated.To support this, an additional qualitativequestionnaire is included, embedded withguidance. Both the quantitative and thequalitative checklist should be completedin parallel as one should be used to informthe other.

Qualitative checklist 1A qualitative checklist should be completedby the subcontractor in conjunction with thequantitative estimate above. This checklistcontains questions on:

� How estimates have been generated.� Why they are the level stated

(i.e. reasons for the waste arising).� What could be done to reduce waste?

To reduce waste the subcontractor shouldconsider the following:

� develop a logistics strategy thatminimises waste;

� use suitable, safe and secure storage;� Consider mechanical systems and

machinery for moving materials;� consider off site manufacture

/construction;� programme and monitor construction

activities;� use packaging in an efficient way; and� train/educate people on how to

reduce waste.

The checklist overleaf encouragessubcontractors to think in detail about whywaste is generated and what they can do toreduce it and it enables the main contractorto respond to feedback from subcontractors –resulting in reduced project waste.



Table 3.1: Quantitative estimate 1

Table 3.2: Qualitative checklist 1This checklist is to be completed in conjunction with the Quantitative estimate. It encouragesthe subcontractor to think about what the waste rates are and how they may be reduced. Itis important to spend some extra time thinking about where waste will occur, how you willaccount for this waste, and importantly, what can be done to reduce this waste.

To download anyof the templates




3.1.2 ImplementationThe implementation of the waste reductionsstrategy relates directly to the constructionphase of the project. At this stage the practicalmeasures to reduce waste on site agreed atplanning stage can be implemented.

During construction, waste reduction andwaste management measures must beimplemented. Contractors and subcontractorsmust ensure that the waste managementsolutions proposed are put into action andtheir effect monitored regularly throughproject reviews.

At each project review, reports on wasteshould be produced to enable the team tocheck performance and look for opportunitiesto reduce waste. As the project progresses,when each trade package is complete, reviewsof their individual performance should becarried out and feedback provided so that:

Construction activities play a very importantrole in the way waste is generated on site atconstruction stage. By working together at thisstage of the project, subcontractors and maincontractors can remove obstacles to materialsefficiency. This can be achieved by taking thefollowing actions:

Implement a Waste Minimisation strategyfor the project as part of the SWMP.SWMPs will become a mandatoryrequirement for many projects throughoutthe UK very soon. As a minimum, theSWMP should contain detailed measuresto comply with relevant waste legislationbut should also include good practiceguidance and objectives in order tomaximise the reduction, reuse andrecovery of construction waste, withdisposal to landfill as the least preferred

option. For further guidance on site wastemanagement, please refer to DTI’s SiteWaste Management Plans, Guidance forConstruction Contractors and Clientsdocument and supplementary guidanceavailable fromWRAPwww.wrap.org.uk/construction.

Develop a logistics strategy thatminimises waste – Poor logistics is amajor contributor to waste. Solutionssuch as a just in time delivery help reducedamage to materials and products byminimising the amount of time they arestored on site. This can be achieved byusing a centralised site materialsdatabase that provides informationon overall project requirements formaterials. In this way, excess call offs canbe eliminated. Planning and coordinatingthe materials ordering processes on siteprevents cumulative over-ordering.

Use suitable, safe and secure storage –For trades or materials where ‘just intime’ deliveries cannot be set up,suitable, safe and secure storageshould be provided so that damageduring storage and moves is avoided.

Consider mechanical systems andmachinery for movingmaterials – Thisis particular useful for trades wherematerials are delivered in large quantities(drylining, brickwork, blockwork). Byusing mechanical handling of materialsdamage and loss during materialsmovement on site is minimised.

Consider offsite manufacture/construction – Offsite manufacture ofelements is becoming a popular methodto improve efficiency and quality. Forexample, the offsite manufacture of wiringlooms for domestic housing enablesexpensive electrical cabling to be usedwith minimal waste. Offsite manufactureminimises the amount of work requiredon site and in particular off-cuts.

Programme andmonitor constructionactivities – This can be achievedby creating metrics which allowmonitoring of performance andcontrol of the construction process.Project management activities shouldalso include regular reviews of thematerials management process. Planning

� subcontractors have a chance to identifyexactly how efficient they were on theproject – in turn enabling them tounderstand how wasteful they were;

� main contractors can see which of thetrades contributed what quantity ofmaterials to the waste stream and why –enabling them to prepare better wasteestimates in the future; and

� lessons can be learned both bysubcontractors and main contractors,enabling both to improve on reducingwaste on subsequent projects.


Implementation

Main contractorsand

subcontractorsreview waste

and take actionto minimise

andmanage waste

2


work in a way that avoids the overlap ofincompatible trades working in the samearea (wet and dry trades) helps reducedamage and rework.

Use packaging in an efficient way –Packaging is one of the largest wastestreams in construction. There aresituations where too much packaging(and sometimes too little packaging) isprovided. Contractors and subcontractorsshould investigate ways of eliminating orreducing packaging. Where possible, takeback schemes for packaging and unusedmaterials with suppliers or alternativelyrecycling the materials at a central depotshould be put in place. The selection ofsuppliers should take into accountwhether they have measures in placeeither to reduce or reuse packaging.

Train/educate people on how to reducewaste – This can be achieved by:

The process of monitoring performanceduring construction should also incorporatethe following best practice activities:

� main contractors should appoint a SiteWaste Manager responsible for reducingwaste on site (at project level). Thedesignation of a Site Waste Managerdoes not need to be a full time task.However it is vital that a designatedindividual has clearly definedresponsibilities in this role and sufficienttime to fulfil the role;

� the Site Waste Manager shouldcoordinate with subcontractors to ensurethat appropriate storage conditions areavailable;

� the Site Waste Manager should keepa record of all materials brought to siteto enable a reconciliation against whatwas used;

� subcontractors should appoint a TradeWaste Manager (at trade package level);

� subcontractors should liaise with theSite Waste Manager to ensure materialsare supplied in an appropriate manner,and in the correct quantity (where notsupplied direct by subcontractor);

� site Waste Manager should monitorcosts/volumes of disposal; and

� the Site Waste Manager to determineKPI’s on this basis.

� raising awareness of therelationship between design, wasteand impact on the environment;

� allocating personal responsibility onsite for waste reduction (e.g. appointa Waste Manager);

� incentivising people to reducewaste;

� sharing experience of good practice;� using training/tool box talks on

waste minimisation andmanagement; and

� enabling more interaction betweenestimators, buyers, site managersand operatives.

Table 3.3 shows a useful checklist for the typeof activities required at implementation stage.


Table 3.3: Construction activities checklist





3.1.3 ReviewA review of waste performance should takeplace when each work package is completed(particularly for long term projects) and also atthe end of projects, as part of the final accountand post project review.

When each subcontractor completes theirwork, a review of its waste performanceshould be carried out. Just a small amountof time reviewing data and providing feedbackcan have real benefits, such as:

Specific actions that can be taken at the endof projects are:

Post completion reconciliation –Comparing the net quantity of materialsused with the quantity ordered and thequantity of materials un-used provides asimple measure of how efficient materialsusage has been. The reasons behind anywaste should be investigated andrecorded.

Carryout reviews of performance againsttargets – ‘All party’ workshops shouldbe carried out at regular intervals as partof project reviews to assess performanceon waste minimisation and management.Good practice requires the clients andcontractor to establish and agree targetsusing Key Performance Indicators(KPIs) for maximising material resourceefficiency. Meeting these targets and KPIsshould become a contractual obligationfor the main contractor and subcontractorand will enable the performance of theproject to be monitored during theconstruction phase. For furtherinformation please refer to WRAP’sAchieving good practice WasteMinimisation and Management document.

Record data – Continuously capturingwaste data across different projecttypes will allow clients, contractors andsubcontractors to build up a clear pictureof how efficient their materials usage isand what effect this had on profit and onoverall project cost. Recording data ona material by material basis will enablemore robust information to be collectedon wastage in different material types/groups. This can then be used to identifyareas where improvements can be made.

To support this process, a quantitative anda qualitative proforma have been developed.

� assess whether the waste minimisationand management strategy was effective;

� learn what works and doesn’t work inreducing waste;

� identify exactly how efficient maincontractors and subcontractors wereon the project – in turn enabling themto understand how wasteful they were;

� main contractors can see which of thetrades contributed what quantity ofmaterials to the waste stream and why –enabling them to prepare better wasteestimates in the future;

� capture any relevant data for futurereference and use; and

� subcontractors and main contractorscan learn lessons, thus enabling bothto improve the waste performance onsubsequent projects.

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Review

Main contractorrequests final

waste informationfrom

subcontractors

Subcontractorscomplete

waste informationquestionnaires

Main contractorcoordinates dataand feeds back

to client

3

Quantitative record 2This is the same form as the Quantitativeestimate 1 used at the planning stage butwith the opportunity to record the actualperformance of the project. This requires thesubcontractor to provide information on theactual quantities of materials used for theproject and compare this against originalestimates. Completing this form effectivelyis likely to require a good degree of datamanagement during the project to ensurethat records are sufficiently robust to identifyactual material usage. Additional guidanceon completing the form is included.

Qualitative checklist 2This is a very simple checklist that exploreswhy the wastage rate is above or below theestimate. It therefore questions what the maincauses of waste were on the project and also,what could have been done to reduce these.This is important information that enablesthe main contractor to build a picture of howto reduce waste on subsequent projects. Inaddition, it also enables the subcontractor tounderstand and document what their wastagerates are, with the intention that they can bereduced. The checklist and guidance oncompleting this can be seen overleaf.


Table 3.4: Quantitative record 2





Table 3.5: Qualitative checklist 2This checklist is to be completed at package final account stage. The benefit of this post projectreview is that it captures the real reasons waste was generated. This helps both contractors andsubcontractors continuously improve their waste performance.




3.1.4 ImprovementBy improving performance, a company candemonstrate best practice and a company-wide commitment to waste minimisationand management for an improved reputationwith clients. The main benefit of improvingperformance in waste minimisation is theability to deliver projects for a lower cost.

Specific actions that can be taken are:

Share lessons learned – One of the bestways to improve performance is to learnfrom experience. The issues relating tominimising and managing waste inconstruction are relatively new and anyexperiences (good or bad) should beshared across the industry. Sharinglessons learned via publications can actas powerful promotion for organisationsand should not be perceived as concedingan advantage to competitors.

Promote innovation – By championingnew ideas in the field of wastemanagement and minimisation, clients,contractors and subcontractors can beat the forefront of the industry andcontribute to increasing government ledrequirements for reducing constructionenvironmental impact.

Raise awareness – By raising awarenesswithin their own organisations and acrossthe industry, all participants to theconstruction process can improve theirperformance on reducing waste, increaseprofits and promote a more sustainableimage of the industry.

Demonstrate better financial andenvironmental results – Contractors andsubcontractors can demonstrate throughexample for future tenders and this canprovide competitive advantage.


Improvement

Share lessonslearned

Promoteinnovation

Raiseawareness

Demonstratebetter financial

andenvironmental

results

Things to consider:Subcontractors should be encouragedto produce informed waste allowances.Designers to provide subcontractors withrobust drawn information.

Subcontractors to identify where the wastearises.Subcontractor to record howmuch waste theygenerate and use this information to informfuture allowances and look for opportunitiesto reduce waste.


Guidance Note 4: Logistics

OverviewAround 15% (by value) of materials deliveredto construction sites is wasted, i.e. it is notincorporated in the construction. Efficientlogistics can play a large part in reducing thisfigure. The development of a robust logisticsplan is fundamental to effectively reduce waste.

Most construction projects involve complexmaterials supply arrangements. A logisticsplan identifies howmaterials are moved to,from and on site and how they are stored.Efficient logistics is based on the rigorousassessment of the need for materials,coordinating delivery, storage and distribution.

4.1 Logistics methodsThere are three traditional logistic methods:

the business takes orders on a jobbingbasis and then visits the supplier toprocure materials piecemeal;the business has materials delivered tosite, typically for larger projects with abulk delivery requirement supplied bytrade outlets; andthe business uses portfolio analysis tosegment ordering processes and call offarrangements. Materials will be deliveredto site and waste is reduced by improvedprocesses.

A fourth and alternative logistics methodinvolves:

the business coordinating a start-to-endprocess and tags information, people andmaterials flows.

Whichever method the subcontractor uses,they will need to get their materials to andfrom site, and move their materials aroundthe site. By not coordinating these materialmovements effectively there is considerablepotential for damage. Materials can be lost,damaged by weather, inappropriately stored,and damaged due to handling errors.A logistics plan will ensure that thisdamage is reduced as far as possible.

The waste reduction solutions identified belowall sit within the envelope of a logistics planand must be considered on a project by projectbasis.

4.2 Logistics solutions4.2.1 Logistics planA logistics plan should be formulated at thestart of a project to enable the Client to planthe delivery of all processes in a project andto assess the supply chains maturity and itsability to align its performance with the client’sobjectives. As the supply chain’s maturitygrows, so will its ability to communicateeffectively throughout the process, leadingto better forecasting. The logistics strategyshould address how waste can be mitigated,and how cost, time and quality can beimproved, detailing information, materialsand people flows.

By adoptingmore efficient logistics, many construction projects couldreduce waste by one-third within a year. Furthermore, in terms ofenvironmental gain, if loads were consolidated then CO2 emissionsfrom deliveries to site would fall by up to 70%.WRAP, Efficient Construction Logistics



Logistics opportunitiesPlanning


Project timeline

• Logistics plan• Materials to site• Materials on site

Logistics planning should be the top priorityas the need for other logistics techniques(described below) such as a consolidationcentres; a logistic specialist onsite and just-in-time delivery will emerge from this action.

WRAP is currently developing a modelapproach to logistics planning consistingof a Material Logistics Plan Template whichwill include aspects of site mobilisation,procurement, traffic management, materialdelivery and distribution and how these linkto the site waste management plan.

4.2.2 Materials to siteLogistics techniques that can improve theefficiency of materials delivered to siteinclude:

Just-in-time deliveryJust-in-time (JIT) delivery is a logisticstechnique when materials are delivered to siteonly at the point when they are required forinstallation. The benefit of this approach is thatit avoids unused materials sitting on site andgetting damaged. When rigorously applied, JITdelivery is one of the most effective techniquesto minimise waste. A logistics specialist (seebelow) can also coordinate the delivery ofmaterials to site.

Consolidation centresConsolidation centres are usually largedistribution facilities that receive, store anddeliver materials, equipment and plant. Theyusually operate a JIT service (see above) andensure that sites receive a reliable flow ofmaterials when and where they are required.

The benefit of consolidation centres isthat they provide a secure environment formaterials storage with efficient handlingprocedures, particularly when materialsmust be pre-ordered due to long lead times.

Take back schemesEncouraging suppliers to ‘take-back’ theirown waste and unused product is a usefulway of diverting waste away from the wastestream. Often suppliers can return un-usedor waste materials to the manufacturer sothat they can be restocked or re-processedinto newmaterial. For example, majorplasterboard manufacturers have committedto taking back clean, waste plasterboard onsites for reprocessing.


Case study 4.1

Mid City Place, Central London, 2004Stanhope, the developer of Mid City Place, quickly recognised that distributionof materials on site would be a critical issue for the construction manager,Bovis Lend Lease, and encouraged a fresh approach to logistics. WilsonJames developed a strategy to reduce multi-handling and repeated movingof materials. Although Wilson James’s brief was confined to the site, itinfluenced, but did not control, deliveries to the gate. However, from that pointonwards, it took the distribution out of the hands of trade contractors.

The twin-track solution:

distributed materials to the workplace just in time for each task; and

created the Market Place, a single onsite distribution point for bulkmaterials and consumables.

At Mid City Place, improve logistics achieved:

some 35% less material waste than benchmark sites;

dry lining waste reduction from 10% to 3%;

distribution with on less pair of hoists than originally expected;

almost 100% performance in materials being distributed in the righttime and place; and

significant savings in contractors’ time related to handling materials.

Bovis Lend Lease and its trade contractors used 4Dmodelling (threedimensions plus time) to produce daily build plans. The 4Dmodel predictswhat will happen each day and the build planning tool sets out the tasks to becompleted and schedules all the components. Wilson James interpreted whateach activity was pulling day by day to create a dynamic schedule of packagingand palletising activities with loading and delivery timings. This ensured JITdelivery and optimal utilisation of the movement team.

The construction of Mid City Place shows that the use of a consolidation orlogistics team on site has a significant impact on JIT delivery. And when usedtogether they have a compounding effect on JIT and therefore on waste. Thisis because consolidation and the onsite logistics team both employ systems topull materials when required and therefore enforce discipline and planning ona somewhat chaotic process.


Fourth party logisticsWhen there is more than one supply chain itis important to ensure there is some kind ofstrategy or centralised coordination of themany logistics providers.

Site demand smoothingConstruction workloads are quite irregular,with the flow of materials reflecting this.This peak and trough supply profile cancreate materials ‘bottle-necks’ wherebyextra pressure on logistics is felt at peaktimes, with a resultant impact on theamount of damage generated.

Demand smoothing is an activity that reducesthese peaks and troughs. By analysing theprogramme, work packages can be balanced(smoothed). This involves starting workspackages either earlier or later, or sequencingthe works so that there is less pressure inspecific areas of a building.

Integrated ICTAn integrated Information CommunicationTechnology (ICT) system across the full supplychain is an interoperable information systemthat tags and tracks materials through takeoff, manufacture, distribution, assembly andinstallation. It tracks the entire process ofmaterials movement from start to end andprovides a matrix for continuous improvement.

Integrated ICT is a powerful logistics solutionas it opens communication along and betweensupply chains. Experience in the retail andautomotive industries have highlighted theimportance of ICT in supply chain integration,JIT delivery and traceability of componentsfrom design through manufacture,distribution, assembly, installation,commissioning, operation, refurbishmentand eventual demolition. Particularly usefulfor large, complex projects, this techniqueprovides a highly transparent picture of whatmaterials are required when.

The construction industry needs to makesubstantial, long-term investment in ICT thatfunctions across the whole supply chain inorder to optimise supply chains. This is alonger term solution but the principles of alean approach to supply chain managementare relevant and applicable in the short termat a local level.

PackagingAs much as 25% of construction project wastederives frommaterials used to package theproducts and materials delivered to sites3.Wherever possible, packaging should beeliminated, reduced or returned to themanufacturer for reuse and recycling.

Packaging waste will require separatethought as it is unlikely that the cost ofpackaging waste will not be divorced fromthe material cost itself. However, there arereal opportunities to reduce the impact ofpackaging. Envirowise have produced specificguidance on minimising packaging wastein construction, accessible fromwww.envirowise.gov.uk/packaging

Below are some of the main opportunities:

Suppliers should be encouraged tore-assess their packaging of materials. Inmany cases this packaging is unnecessaryand expensive, resulting in increasedcosts to manufacturers and to contractorsfor disposal. By working together betterpackaging solutions may be available thatactually reduce damage. It is worthconsidering that an abundance ofpackaging can have the effect of devolvinga duty of care for the material inside asit becomes the job of the packaging toprotect it, and not the individual. Reducedpackaging would require more care to beapplied, not necessarily more waste.

Effective logistics solutions can alsohelp to reduce accidental damage. Ifthis damage is reduced then the need forpackaging (or protection) can be reduced.

Packaging waste can be reduced throughminimising the use of void-space fillersand specifying lightweight, down-sizedpackaging.

Where minimising packaging wasteis not an option, there is a need toencourage the supply chain to takeresponsibility for reusing and recyclingpackaging. There have been someadvances in making packaging reusable(such as in structural packaging: pallets,crates, sturdy plastic/cardboard boxes,and stillages for delivering windows).Where possible such reuse should takeplace or a take back scheme arranged.

3 Envirowise, ‘Managing packaging waste on your construction site’.

Where none of the above solutions areavailable, packaging should be segregatedfor recyling. For more information onminimising andmanaging packagingwaste, please see Envirowise,Managingpackaging waste on your construction site.

4.2.3 Materials onsiteOnce materials have arrived onsite there area number of logistics techniques that can beapplied to ensure materials are handled andstored effectively to minimise damage andresulting waste.

Materials handling strategySimply moving materials around site results indamage and thus, waste. Insulation boards getcrushed and plasterboard edges get damaged.Using small, moveable trolleys that aredesigned to carry the appropriate materialsensures that materials can be moved aroundsite with ease. In addition, if these are kept to amanual handling size then there is less changeof accidents (both to the materials and theworkforce). Furthermore, a total reduction inmaterial handling through for exampledelivering materials direct to point of use orthe use of appropriate mechanical plant willalso reduce waste.

Logistics specialist on siteUsing a specialist logistics team onsitethat receives deliveries, coordinates anddistributes materials, on a JIT basis can helpreduce waste by taking the materials handlingissue away from subcontractors. Logisticsspecialists can also coordinate and control thedelivery to site. By giving the task of materialsmovement to a specialist team, they can focuson this alone and put in place solutions toreduce damage. Relatively straightforwardsolutions such as sufficient storage ofmaterials onsite can be coordinated by thelogistics specialist. This ensures that materialwaste from damage and programming andplanning is minimal.


Case study 4.2

Everest LtdEverest Ltd, a manufacturer of double-glazed windows and conservatoriesrealised that it could reduce packaging without increasing damage to itsproducts during transit. The company stopped using stretch-wrap aroundthe glass frames and used a new delivery system. The packaging supplierproduced redesigned packaging made out of foam protectors at less costwhile still providing the required protection.

Case study 4.3

Wolseley Distribution System, 2006Wolseley, one of the world’s largest suppliers of building products, madea £100m capital investment in a distribution system under which its 10,000suppliers deliver (in full loads) to just three regional construction centres.From there, a fleet of purpose-designed vehicles deliver (also in full loads)to its 1,800 outlets. The result is 50% reduction in the number of vehiclesdeployed, 35% less material waste and knock-on productivity improvements.Wolseley claims it can save 18% in the cost of materials by using this betterlogistics method.

Pallet wastePackaging accounts for around 11% of total timber use in the UK,predominantly for pallets – 87% of all wood packaging. Pallets are used fordelivery of a broad range of products. WRAP research has shown that many ofthe medium to larger housebuilders and construction companies, particularlythose active in social housing have sufficient influence over their supplychains to demand that suppliers recover their pallets. Furthermore, largedevelopments and refurbishment projects make it economically viable forsuppliers to take back their used pallets.


Materials storageToo often materials are seen on site sittingin the mud, or out in the rain. If materials arekept on site it is important that they are storedin an ordered and protected environment.Materials like plasterboard requireweatherproof environments whilst blocksand aggregates ideally require an area ofclean, hard-standing.

Programme planningBy ensuring there is not overlap of trades onsite, material damage can be reduced. Thesequencing of works is important to avoid onetrade damaging the work of others. This is acommon problem in construction whenprogrammes get squeezed and there is a rushof activity at the finishing stages of a project.The result is often significant snagging withan associated waste stream.

Culture and trainingTo ensure that sites operate efficiently, aprogramme of education and awarenessraising can help reduce waste. By briefingsite operatives that waste minimisation isan important objective and that accidentaldamage should be reduced, hopefullyoperatives will take greater care whenhandling and installing materials.

Things to consider:Subcontractors should be encouragedto produce informed waste allowances.Designers to provide subcontractors withrobust drawn information.Subcontractors to identify where the wastearises off-cuts or damage).Subcontractor to record howmuch waste theygenerate and use this information to informfuture allowances and look for opportunitiesto reduce waste.

7.0 Conclusion

This guidance provides comprehensiveinformation for construction clients, designteams and main contractors for achievinggood practice waste minimisation on theirconstruction projects. This will help reducethe amount of construction waste sent tolandfill, thus demonstrating a contributionto sustainable development and reducingproject costs.

Good practice Waste Minimisation can beachieved on all forms of project without afundamental change in working practice.In summary, key aspects of achieving goodpractice waste minimisation include:

early project implementation by the clientto maximise potential benefits;setting requirements for its delivery by theentire supply chain;ensuring that waste minimisationbecomes part of the agenda of the project;andadopting a SWMP in accordance with goodpractice to inform design and managewaste on site.

WRAP have produced two further guidancedocuments for achieving good practice wasteminimisation: a high-level business case forclient decision makers and an introductoryguidance document outlining the opportunitiesfor waste minimisation by the client, designteam, contractor and supply chain. Inaddition, WRAP’s construction portalwww.wrap.org.uk/construction containsextensive related information covering allaspects of materials use in construction,including case studies, reference guidesand managing specific waste streams.


WRAP and Davis Langdon believe the content of this report to be correct as at the date of writing. However, factors such as prices, levels of recycled content and regulatoryrequirements are subject to change and users of the report should check with their suppliers to confirm the current situation. In addition, care should be taken in using anyof the cost information provided as it is based upon numerous project-specific assumptions (such as scale, location, tender context, etc.).

The report does not claim to be exhaustive, nor does it claim to cover all relevant products and specifications available on the market. While steps have been taken toensure accuracy, WRAP cannot accept responsibility or be held liable to any person for any loss or damage arising out of or in connection with this information beinginaccurate, incomplete or misleading. It is the responsibility of the potential user of a material or product to consult with the supplier or manufacturer and ascertainwhether a particular product will satisfy their specific requirements.

The listing or featuring of a particular product or company does not constitute an endorsement by WRAP and WRAP cannot guarantee the performance of individualproducts or materials. This material is copyrighted. It may be reproduced free of charge subject to the material being accurate and not used in a misleading context.The source of the material must be identified and the copyright status acknowledged. This material must not be used to endorse or used to suggest WRAP’s endorsementof a commercial product or service. For more detail, please refer to WRAP’s Terms & Conditions on its web site: www.wrap.org.uk.

Waste & ResourcesAction Programme

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Tel: 01295 819 900Fax: 01295 819 911E-mail: [email protected]

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www.wrap.org.uk/construction

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