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IntroductionThe project’s aim is investigating 4 building types covering a range of structural timber product, they are:-

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Industrial Shed

Image: Timberbuilt

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Two Storey Aged Care Facility

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Seven Storey Office Building

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Eight Storey Apartment building

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Todays ProgramAll buildings findings will be discussed but to various extent◦ Portal Frame – very quickly◦ Aged Care – very quickly◦ Apartment building – some details◦ Office building – more details

So apologies in advance if the presentation is missing some details

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Outputs1. Cost Plan for each building type comparing timber versus non-wood system

2. Commentary to the building considered, decisions taken and in some instances discussion on alternative systems

3. Bill of Quantities for all buildings, i.e. so you can do your own Cost Plan

4. Final report (on FWPA website)

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Team of Experts Architect◦ Fitzpatrick and Partners ◦ Studio505

Structural Engineer ◦ Arup Ltd◦ TTW◦ AECOM◦ Timber: specific input via various organisations – Meyer Timber, Timber Development Association, Nelson Pine

Industry

Acoustic ◦ Arup Ltd, PKA

MEP◦ Arup Ltd

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Team of Experts Construction project management◦ RBE Contracting - A construction contracting company with expertise in many

forms of building construction and specific expertise in large scale timber construction.

Cost Planner◦ Building Cost Information Service – A subsidiary of the Royal Institute of

Chartered Surveyors who operate globally. BCIS specialise in building cost trends and indexing services for a wide variety building forms.

Coordination and Strategic Direction◦ University of Technology Sydney – co-developed the research method and

mediated the strategic direction of timber solutions where pertaining to detailed design, construction and site productivity issues.

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Portal Frame

Image: Timberbuilt

Building ParametersBuilding Location◦ Outer Sydney Suburbs

Building Height◦ One storey ◦ 5.0 m to underside of eaves

Building Area◦ 32.0 m span x 40.0 m length ◦ Gross Floor Area - 1,200 m2

Building Classification ◦ A Class 7b building i.e. wholesale distribution shed

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What was Considered Three Designs ◦ Timber Solution 1 - 6.7 m portal spacing◦ Timber Solution 2 - 10.0 m portal spacing◦ Steel Solution 1 - 8.0 m portal spacing

Why different spacing◦ Not to bias result in favour of one material◦ Two timber structures were tested to find best result

Design based on a Cost Plan undertaken by Structural Timber Innovation Company

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Cost Plan Outcomes

Timber portal solution 1

6.67 m Bay Spacing

Timber portal solution 2

10 m Bay Spacing

Steel portal solution

8.0 m Bay Spacing

Purlin $39,483.00 $67,965.00 $36,510.00

Girts and mullions $20,761.00 $28,247.00 $33,740.00

Portal Frame $147,310.00 $78,530.00 $165,040.00

Footings $19,480.00 $22,000.00 $33,540.00

Totals $227,034.00 $196,742.00 $268,830.00

Variance -$41,796 -$72,088 0

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Two Storey Aged Care

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Building ParametersBuilding Location◦ Outer Sydney Suburbs

Building Height◦ Two storey ◦ 6.0 m to underside of eaves

Building Area◦ Gross Floor Area - 1681 m2 ◦ Floor Space Ratio - 0.67:1

Building Classification ◦ A Class 9c building i.e. an aged care building

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What was considered?Two options◦ Lightweight timber frame◦ Lightweight steel frame

All other aspects of the building were identical ◦ Foundation◦ Concrete ground floor slab◦ Surface coverings to walls, floors, roof and exteriors identical◦ MEP, and so on

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Cost Plan OutcomesTimber Steel

Columns $2,646.00 $3,330.00

Upper Floors $63,138.00 $226,357.00

Roof $259,611.00 $300,635.00

Walls $371,625.00 $279,298.00

Total $697,020.00 $809,620.00

Variance -$112,600 0

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Cost Plan OutcomesTimber framed building was ◦ $112,600 cheaper

Saving for the timber building were found in;◦ Floor; $163,219 ◦ Roof; $41,024

Additional cost were found in ◦ Walls; $92,327

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Quotes from the marketplaceReal quotes were obtained from leading frame suppliers as a package delivered to site.

The quotes for frame material only, (note the outcome of the cost plan include coverings.) ◦ Steel price - $231,000 ◦ Timber price - $193,133

Timber had a $37,867 saving or 20 percent

A better saving than the Cost Plan

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Eight Storey Apartment building

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Building ParametersBuilding Location◦ Sydney Suburbs

Building use ◦ 7 storey apartments◦ 1 storey retail◦ 2 storey subgrade basement parking

Building Height◦ Eight storey ◦ Overall height 25.900 m, (Effective height 22.790 m)◦ Floor to floor

◦ Apartment 3.130 m, ◦ Retail 4.0 m

Building Area◦ Gross Floor Area - 6080 m2

◦ Retail 348 m2◦ Apartment 5320 m2

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What was consideredTwo options◦ Post Tension Concrete building – base model◦ Cross Laminated Timber building

Where aspects of the building were identical, they were not included in the Cost Plan, these include;◦ Foundations◦ Subgrade concrete car park◦ Retail and utility zone on ground level◦ Fit-out◦ MEP, and so

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Walls - Apartment

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Walls - ApartmentExternal Wall◦ Wall Type 1 – 125 mm thick 5 layer longitudinal faced CLT panel with 10

mm plasterboard internal coverings and aluminium composite commercial facade exterior coverings

Walls bounding Apartment ◦ Wall Type 2 - 95 mm thick 5 layer transverse face CLT panel with timber

stud and 13 mm plasterboard, refer to Figure 6. Fire resiting plasterboard is direct fixed to both sides of CLT dependent on the level within the building;◦ Level 1 and 2 – 2 x 13 mm fire resisting plasterboard◦ Level 3, 4 and 5 – 1 x 13 mm fire resisting plasterboard◦ Level 6 – no additional plasterboard

◦ Rw + Ctr; 54

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Walls - ApartmentInternal Loadbearing Wall◦ Wall Type 3 - 95 mm thick 5 layer transverse faced CLT panel, refer to

Figure 7. Fire resiting plasterboard is direct fixed to both sides of CLT dependent on the level within the building;◦ Level 1 and 2 – 2 x 13 mm fire resisting plasterboard◦ Level 3, 4 and 5 – 1 x 13 mm fire resisting plasterboard◦ Level 6 – no additional plasterboard

Internal non-loadbearing wall◦ 70 mm timber frames with 10 mm plasterboard or 6 mm f’c.

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Walls - ApartmentLift and Stair Shaft◦ Inner layer: Wall Type 5 –

◦ 125 mm thick 5 layer longitudinal face CLT panel no wall linings either side,

◦ Outer layer: Wall Type 6 –◦ 95 mm thick 5 layer transverse face CLT panel with 2 x 13 mm fire rated plasterboard on

exterior shaft side

◦ Acoustic◦ Rw + Ctr; 54◦ Resilient strip placed between CLT to maintain 20 mm gap◦ Discontinuous construction CLT’s acoustic performance are based on Tillings/KLH

assessments

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Floor - Apartment

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Facade

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Facade

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Lateral Resistance

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Concrete Solution

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Walls - ApartmentExternal Wall◦ 75 mm aerated lightweight concrete panel with aluminium composite

commercial facade cladding and 10 m plasterboard interior

Walls bounding Apartment ◦ 75 mm aerated lightweight concrete (Hebel) panel, with 64 mm steel

stud and 13 mm fire resisting plasterboard linings both side of wall. ◦ 20 mm air gap between aerated concrete and steel stud and 75 mm glass

wool in air gap29.◦ Rw + Ctr; 53

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Walls - ApartmentInternal non-loadbearing wall◦ 64 mm metal frames with 10 mm plasterboard or 6 mm f’c.

Lift and Stair Shaft◦ Inner layer - 200 mm concrete◦ Outer Layer - 64 mm metal stud with 13 mm plasterboard ◦ Acoustic

◦ Rw + Ctr; 54

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Floors – Apartment

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Floors – Apartment 200 mm concrete slab, with furring channel at 600 crs, supporting 10 mm plasterboard. 50 mm polyester insulation is placed between furring channel.

Acoustic◦ Rw + Ctr: 53◦ Ln,w +Ci: 35 to 40 with carpet and underlay

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Cost Item Not consideredMany of the items in the cost plan have not been included as they are cost neutral between each model building, some of these include;◦ Mechanical, Electrical and Plumbing: both building use the same layout and assumptions. ◦ Façade cost: both model buildings are the same height and use identical cladding that is fixed in a

similar manner. ◦ Floor finishes: both model building don’t include a floor finish.◦ Crane cost: both model buildings assume the same crane has been used.◦ Scaffold: both model buildings assume the same scaffold has been used.

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Comparison

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Cost Plan OutcomesOverall the Timber building was $110,478.00 cheaper or 2 percent

Saving for the timber building were found in;◦ Transfer slab Level 1 - $277,825◦ Apartment floors - $102,800◦ Roof - $50,115◦ Preliminary - $292,000

Additional cost were found in ◦ Walls covers; $92,327 or 33% increase

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Seven Storey Office Building

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A Model Office Building◦ The model aims for realism, not (timber oriented) idealismThe office model building has a:◦ Floor plate area – 1,944 m2

◦ Width 27m ◦ Length 72m◦ 7 storey timber construction (structural frame only) above ground◦ 9m column grid (occupant and parking needs)◦ Direct load paths, no transfer slab◦ Glass façade (non-combustible in terms of meeting NCC requirements)◦ Only lift/stair shaft load bearing walls

Structural, Fire and Acoustic parameters were applied to the model to better inform design requirements

Both timber and concrete solutions were then created to suit◦ The timber design only applies to the structure of the 7 above ground levels◦ Non-timber below ground with 2 storey of car parking ◦ Other aspects are the same for both solutions

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The Timber Solution utilises high levels of prefabrication

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Design Options30 separate design (mainly floors) were investigated before the solution was used in the comparison

Other designs options may work in different situation and should not be discounted – worth a look

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Issues that drove the design (in order of consideration)

Floor cavity depth

MEP (Mechanical, Electrical and plumbing) – HVAC affect on floor cavity depth

Floor Dynamics – floor system

Acoustic solution

Fire resistance solutions – mass timber versus fire rated plasterboard

Availability of systems – who can supply and assemble it nearby

Program time = $$$$ (especially in prelims)

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Fire Resistance Fire resistance was provided by increasing the thickness of timber and using its capacity to char

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Primary Beam – Paired 800 x 180 mm LVL13

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Primary BeamPaired 800 x 180 mm LVL13 straddles either side of column

Timber blocks act as beam spacers and reduce fire exposure between the paired beams

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CNC Fabrication LVL beams and columns are fabricated in a CNC machine for accuracy and to allow direct digital transfer from the digital design to the cutting room

TimberLab New Zealand 57

Primary Beam Propped Cantilever was used to create a zone to run HVAC

Paired 400 x 180 LVL11 was used between propped ends of primary beams

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Other Beam OptionsOther beam options were considered such as ◦ Box LVL beam◦ Glulam

However, in this model building the paired LVL primary beam worked well as it reduced the floor cassette span

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ColumnsColumns three levels high◦ Ground to Level 3 – 600 x 311 LVL13◦ Level 3 to Level 6 – 400 x 311 LVL13◦ Level 6 to roof – 300 x 311 LVL11

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FloorMassive LVL Cassette◦ Bottom LVL layer designed to achieve fire resistance

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Floor

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Secondary BeamNo secondary beams used to support the floor.

A 400 x 180 LVL13 beam was used at the building perimeter to support façade

The beam was included in the floor cassette to reduce crane movements (discussed later)

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Core and Shafts185 mm CLT

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Core and Shafts

Also provides lateral resistance to building 65

How does the Timber Model come together?

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Concrete ModelColumns ◦ L0 to L3

◦ Edge: 400 x 400◦ Centre: 450 x 450

◦ L3 to Roof◦ Edge: 350 x 350◦ Centre: 400 x 400

Post Tension Band beam◦ Slab 170 mm (some 200 mm areas)◦ Band beam

◦ Primary 1800 x 350 mm◦ Edge 900 x 350 mm

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HVACSolution the same between models

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Workflow & Speed Onsite for the Timber Solution

Labour force◦ A crew of 6 (excluding crane driver, dogman, traffic control, etc.).◦ The small crew size is due the limits of people that can work around the

movements (& cycle time) of a single crane◦ The small crew was possible because of the high levels of panelised

prefabrication◦ Panel connection/joining methods used simple hand held power drilling

technology and self driven screws

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Program TimeThe Concrete and Timber solutions both had a programme developed for the 7 storey above ground structure (columns, floors, roof, core shaft)

The Timber solution was estimated to take 78 days

The concrete solution was estimated at 117 days including formwork, stripping, curing and back propping

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Workflow and Speed Onsite for the Timber Solution

Timber Solution saved 39 days

Time savings were also possible in terms of faster commencement of the interior work (e.g. ductwork, ceilings, plumbing, etc.)◦ Concrete model interior work could commence on Day 51◦ Timber Model interior work could commence on Day 16

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Many Neutral Cost ItemsMany of the items in the cost plan are cost neutral between the timber and concrete solutions:◦ Mechanical, Electrical and Plumbing: both building use the same layout and assumptions. ◦ Façade cost: both model buildings are the same height and use identical cladding that is fixed in a

similar manner. ◦ Floor finishes: both model building don’t include a floor finish.◦ Basement construction is identical◦ Flat roof membrane and ballast are identical

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Cost Plan ResultsTimber

with ceilingTimber

without ceilingConcrete

Columns 444,825.00 444,825.00 234,424.00Floor

Beams 1,481,982.00 1,481,982.00Floor Cassettes 2,772,518.00 2,772,518.00

4,254,500.00 4,254,500.00 4,422,810.00Roof

Beam 207,387.00 207,387.00Roof Cassettes 352,569.00 352,569.00

559,956.00 559,956.00 689,720.00

Lift, Stair and Air shafts 793,698.00 793,698.00 1,177,620.00

Suspended Ceiling 764,934.00 0.0 764,934.00Connectors 59,769.00 59,769.00 0

Termite & Fire Eng 50,000.00 50,000.00 0.00

Preliminary Adjustments -460,000.00 -460,000.00 Nil

Total $6,387,913.00 $5,889,018.00 $7,289,508.00

Variance -$901,595.00 -$1,400,490.00 0 79

Main Areas of Saving Using TimberMain savings offered by the timber solution in rank order include:◦ Cheaper floor construction (via prefab cassette floor panels)◦ Ext/Int cores walls (CLT vs concrete)◦ Preliminaries◦ Roof construction cheaper (framed timber vs concrete slab)

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Cost Savings in PreliminariesThe cost plan assumes the same crane, scaffold, supervision, site sheds were used for both concrete and timber but?

The Timber solution saved 8 weeks in construction and assumed a subsequent saving of $57,500 per week (mainly assigned to reduced crane hire) being a total saving of $460,000

Preliminary saving represent the major difference in cost between the timber and concrete models

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Preliminary costs still need further investigation?

Savings associated with faster internal construction◦ The current cost plan ignores potential cost savings associated with the potentially faster internal construction

associated with the timber solution.

Scaffolding ◦ Timber structure can be constructed with hand rails already attached to floor panels. This removes the need

for scaffolding to the outside of the building, only required for façade system. This potential large saving has not been included at this point in time.

Screens◦ Timber structure can also be constructed without the need of temporary screens to the outside face of the

scaffold. This potential saving has also not been included at this point in time.

Site Accommodation◦ Potential for shorter hire period due to compressed schedule for timber.

Crane size and type◦ It is conceivable that a light electrical and remote crane could be used.

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Timber Model - Additional CostsThere are a few additional cost for the timber solution that do not apply the concrete solution:

Fire Engineering ◦ The timber model requires an Alternative Solutions for the (CLT) core walls enveloping the stairs, lift and

mechanical air shafts. ◦ Fees were estimated to be $20,000, based on quotes from Sydney fire engineers.

Termite Protection◦ Both models sit over a two level concrete basement garage. ◦ The timber structure has considered termite protection ◦ Preservative treatment to columns only (Ground to Level 3) – included in Costs Plan under materials ◦ Slab edge exposure at ground level to facilitate regular inspection – included in Costs Plan under materials ◦ Stainless steel mesh to all hidden entry points - $30,000

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Other Potential Cost SavingsConsider that the Timber Model doesn't need a ceiling◦ Deduced ceiling savings $764,934◦ 19 % better than concrete solution◦ Applied finish occurs at factory◦ Minor additional cost may occurred because of improved appearance of ducts and other services

Footing Costs ◦ As timber is 1/5 weight of concrete this allows smaller footings for the timber model.

Columns◦ The timber columns come with a weather protection sealer. No additional surface treatment is required,

whilst concrete columns require furring and plasterboard installation.

Fit-out time◦ The time to carry out fit-out activities in timber structures are generally less as there is less time to fix brackets

and supports onto the superstructure. Timber structures use cordless screw guns which are light, quick and easy to use. Concrete structures require drilling into concrete, which is slow, noisy and dirty work.

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Key Value/cost messagesThe floor system is the most cost sensitive part of the timber solution

Timber columns are more expensive than concrete due to added fire (charring) requirements.

Best to use an engineer to seek the best FRL rating and solution for expensive items i.e. $100,000 saved on reducing column x-section and related FRL

Preliminary costs and the construction schedule must be taken into account to realise savings

Timber Model - Key Design Considerations

1. Use standard stock sizes LVL panels/billets; Use intelligent structural design to reduce billet wastage.

◦ Like steel there is a cost factor of 2 to 2.5 difference between stock elements and fabricated elements.

2. Timber char is cost effective fire resistance when the least amount of surface area is exposed

3. Consider crane movements on the project. Large elements result in shorter program time

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Carbon MeasuringDOUBLE LINE ACCOUNTING

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Carbon MeasureUTS undertook a measure of carbon emissions on the apartment and office building for both concrete and timber solutions

The boundary conditions was set as cradle to factory gate

Ignored operational and disposal issues, the later being a negative for timber

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Carbon Measure ResultsOffice Building◦ Concrete office building was found to have 4.4 times greater greenhouse gas potential

Apartment Building◦ Concrete apartment building was found to have 2.1 times greater greenhouse gas potential

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Carbon Measure

Note:CL - ColumnsUF - Superstructure floors & beams

RF - RoofsEW - External walls

NW - Internal wallsWF - Wall finishes

FF - Floor finishesCF - Ceiling finishes

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GWP fro each building element

Note:CL - ColumnsUF - Superstructure floors & beams

RF - RoofsEW - External walls

NW - Internal wallsWF - Wall finishes

FF - Floor finishesCF - Ceiling finishes

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ConclusionsFloor Vibration Assumptions (dynamics): ◦ Guidance is required on the assumptions and calculation methods for long span timber floors. Current

FWPA project (UTS)

Floor Diaphragm: ◦ Improved guidance on design of diaphragm action of large spaning timber floors. Some information in

EXPAN guides but not enough.

Timber shear wall design: ◦ Guidance on the design of timber based shear walls.

Connectors Design and Standards: ◦ Updating the Australian Standard AS1720 to remove over conservatism and include proven innovative

European connector systems. Planned but many years away

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ConclusionsBetter Acoustics Systems for Floors: ◦ Development of acoustic systems for timber floors that don’t rely on ceiling or building up layers on the

top surface for increased acoustic performance.

Fire Resistance of Timber Panels: ◦ Provide information on maintaining fire resistance in the joining of massive timber panels as well as

provide certification for fire protection to systems that may penetrate timber elements such as doors, pipes, cables, service shafts, etc. Joining of massive timber barriers is current FWPA project.

Preliminary Costs: ◦ Provision of empirical evidence that timber buildings are quicker to erect. Current FWPA project with

UTS

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Is there real potential out there or is it just a nice exercise?

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Barangaroo C2

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Thank YouParticularly the Design Professionals and Industry who helped out with the project

Questions

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