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Interlocking Stabilised Soil BlocksAppropriate earth technologies in Uganda

Appropriate technology that doesn’t cost the earth



Please send your feedback and suggestions(including further case studies for consideration) to:

Dan LewisDisaster Management ProgrammeUN-HABITATEmail: [email protected]

© UN-HABITAT/Adrian Perez



Copyright © United Nations Human Settlements Programme(UN-HABITAT) 2009

All rights reservedUnited Nations Human Settlements Programme (UN-HABITAT)P. O. Box 30030, 00100 Nairobi GPO KENYATel: 254-20-7623120 (Central Office)Fax: [email protected]

www.unhabitat.org

HS/1184/09EISBN: 978-92-1-132150-0

DISCLAIMER

The designations employed and the presentation of the materialin this publication do not imply the expression of any opinionwhatsoever on the part of the Secretariat of the United Nationsconcerning the legal status of any country, territory, city or areaor of its authorities, or concerning the delimitation of its fron-tiers of boundaries. Views expressed in this publication do notnecessarily reflect those of the United Nations Human SettlementsProgramme, the United Nations, or its Member States. Excerptsmay be reproduced without authorization, on condition that thesource is indicated.

ACKNOWLEDGEMENTS

Editorial Team: Mohamed El Soufi, Dan Lewis, Filiep Decorte, Mo-nique Iglebaek, Tom Osanjo, Christophe Lalande, Caylee Hong, LisaBaumgartner, Dan Andabati, Adrián Mauricio Pérez-Peña

Principal Editor and Manager: Filiep Decorte and Monique IglebaekPrincipal Author: Adrián Mauricio Pérez-PeñaDesign and Layout: Adrián Mauricio Pérez-Peña

Photography by Lisa Baumgartner, Peter Donde, Caylee Hong,Adrián Mauricio Pérez-Peña, Manuel Scrima, James Morris, Univer-sity of Utah, Vetsch Architects

Participating Individuals and Organizations (in alphabetical order):Arup Consultants: Mathew Bloodworth, Hugh Gray, George Irwin,Ewan Smith, David WilliamsBULA Inc: Melissa Fricke and Andrea ProcopioCARITAS: Rev. Fr. Vincent Kisenyi-Byansi and Bro. Kayondo MathiasCentre for Research in Energy and Energy Conservation in UgandaConnect Africa Resource Centers: Trevor TychonGood Earth Trust: Sophie Mills, Bobby LembertHaileybury Youth Trust: Helen GoddardJoy Center: Rev. Canon Benoni Mugarura-Mutana

Kampala Hospital: Kawalya KanyerezeLords Meade Vocational School: Godfrey KigangaMakiga Engineering: Ken ShivachiMalewa Trust in KenyaMount Meru Millers Ltd.: R.K. BharhavaNotre Dame High SchoolOyani Women’s Group (Kenya): George TitoPresidential Initiative to Support Appropriate TechnologySt. Matia Mulumba PolytechnicTechnology for TomorrowThe Jane Goodall InstituteUN-HABITAT: Robert Adupa, Peter Donde, David Kithakye, PeterWegulo


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U N - H A B I T A T / A d r i a n P e r e z


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foreword

I am pleased to share with you this publication, which is based on acollaboration between UN-HABITAT and Good Earth Trust (GET). GETis an organisation that promotes the adoption of high quality andenvironmentally friendly construction technologies in East Africa. Bydeveloping and promoting low-cost and sustainable building materi-als and construction technologies it is therefore contributing to theattainment of the Habitat Agenda and the overall goal of “adequateshelter for all”.

The civil war in Northern Uganda left thousands without homes andstripped the landscape of a good part of its trees and foliage. Inspiredby UN-HABITAT’s Strategic Policy on Human Settlements and Crisis,

our response has focused on helping to speed up the return of dis-placed persons and the process of reconstruction and recovery. Put-ting in place critical infrastructure and services is essential to this task.In a war-ravaged landscape, appropriate construction technologieshelp to ensure the recovery of the environment which is so essentialin supporting people’s livelihoods. Darfur, Eastern Congo, and Somaliaare other examples in the region where similar approaches have beenpiloted successfully and will hopefully be more widely utilized.

This publication also demonstrates how environmentally-friendly build-ing materials and construction technologies can be made more afford-able to the urban poor while still meeting rigorous building standards.These techniques also help in mitigating climate change by avoidingcarbon emissions during the production of building materials and con-struction as well as by saving thousands of trees. This publication isintended to help promote the use of earth construction in a widerregion where conditions permit, as part of our efforts to address theglobal challenges created by climate change.

It is my sincere hope that this publication will be a source of inspirationto all those who want to help change the way we deal with our envi-ronment while meeting the urgent housing needs of people in placeslike northern Uganda.

Anna K. TibaijukaExecutive DirectorUnited Nations Human Settlement Programme(UN-HABITAT)


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U N - H A B I T A T / C a y l e e H o n g


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preface

Meeting the need for adequate housing of the world’s population re-quires sustained investment and continued innovation, particularly inappropriate technologies that lower the cost of construction and thecost to the environment.

Interlocking Stabilised Soil Block (ISSB) technology is one such tech-nology that is gaining growing recognition, notably in East Africa.Compared with alternatives such as fired brick, it offers lower con-struction costs at comparable quality, is suitable for a wide range ofenvironments, and dramatically reduces the impact on the environ-

ment. With a growing number of organisations using the technologythere is a need to improve communication and knowledge-sharing, toquantify and verify the benefits, and to develop efficient approachesfor its promotion and adoption.

The purpose of this publication is to promote the use of the tech-nology by sharing some case studies of successful ISSB adoption andadaptation to local contexts. It also highlights some of the challengesfaced in developing and promoting the technology with some key les-sons learned from the growing amount of practical experience. It isa contribution to the process of information exchange and a tool tobuild awareness amongst key stakeholders interested in the sustain-

able development of human settlements.

As the UN agency concerned with human settlements, UN-HABITATis committed to supporting the development and promotion of thistechnology. The Good Earth Trust, which is dedicated to the promo-tion of such technologies and focusing specifically on ISSB, welcomesthis publication as an important and timely contribution.

Good Earth TrustDisaster Management ProgrammeUN-HABITAT


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introduction

“The building and construction industry is considered a key player in sustainable development, with the potential to signifi-cantly impact society and the environment” (Shelter Initiativefor Climate Change Mitigation).

There is a need to promote awareness of appropriate constructiontechnologies in civil society and the private sector. Appropriate tech-nologies refer to materials, methods and/or practices which help pro-tect the natural environment, take inspiration from the cultural valuesand practices in the area, make use of local resources, and contribute

to local economic development.

In conflict or disaster affected areas, the natural environment is oftenseriously degraded due to the direct damages and the overall lack ofmanagement and care. Like in Uganda, traditional building techniquesoften consume a lot of wood and the massive reconstruction needsrisk to further accelerate the environmental degradation. An importantaspect of “building back better”is the use of appropriate technologiesthat help preserve the environment, are affordable and create newlivelihood opportunities.

This publication discusses the use of Interlocking Stabilised Soil Blocks

(ISSB) within the context of Uganda, as an alternative to burned bricksand wattle and daub amidst the return of thousands of displaced andthe need for reconstruction of schools and health facilities. This tech-nology makes use of soil for the making of blocks which is naturallyor chemically stabilized and then compressed by manually operatedor motor-driven machines. This publication deals only with the blocksmade with the manually operated machine as it is the most afford-able option, more easily transferable to different contexts, and easy touse and maintain. The use of earth for building is already a commonpractice in Uganda. The production of ISSBs can provide new livelihoodopportunities. The benefits of ISSB are manifold and its use versatile.

This publication has been created in order to promote awareness ofISSBs as well as to illustrate the challenges and lesson learned of differ-ent organizations in Uganda using this technology. By compiling andgathering data of these different organizations, common challengescan be summarized, providing a way forward to further develop thetechnology.


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Types of Earth Architecture......................................................................................2

Development of ISSB Technology.............................................................................4

SSB Technology General Information........................................................................6

Block Production Process..........................................................................................8

Comparative Studies and the ISSB Advantage.........................................................10

Construction Methodologies used in Uganda..........................................................12

INTERLOCKING STABILIZED SOIL BLOCKS.................................................................. 1

ISSB CASE STUDIES................................................................................................................15

LESSONS LEARNED.................................................................................................................33

WAY FORWARD .......................................................................................................................39

UN-HABITAT Teachers’ Housing..............................................................................16

ARUP Consultants..................................................................................................18

CARITAS.................................................................................................................20

Connect Africa.......................................................................................................22

HYT........................................................................................................................24

PISAT....................................................................................................................26

BULA Inc................................................................................................................28

CREEC.....................................................................................................................30

T a b l e o f C o n t e n t s



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INTERLOCKING STABILISED SOIL BLOCKS



Over the ages, Earth Architec-

ture has always provided com-

munities with basic protection

against harsh climatological

conditions. The grand mosques

of Mali and the Yemeni towns

are just two examples of rich

cultural expressions of refined

civilizations that expressed

themselves through Earth Ar-

chitecture.

Today, Earth has taken a back

seat as a material of choice for

dwelling construction. Cementblocks and iron sheets are now

signs of modernity and prog-

ress even in the most remote

communities. Traditional con-

struction techniques and forms

of expression give way to new

‘global’ aesthetics, often harm-

ing the environment, and pro-

ducing architecture irrespon-

sive to the climatological and

cultural context. Overall, thetraditional construction skills

needed for working with earth

are eroding. In some cases, the

over-reliance on wood - which

is increasingly hard to get - and

recurrent maintenance require-

ments have helped to speed up

the disappearance of Earth Ar-

chitecture.

Different contextual factors,such as climate, have shaped

earth construction techniques.

The predominant earth con-

struction techniques are:

© James Morris2

TYPES OF EARTH ARCHITECTURE



Adobe blocks are similar to CEB’sand sometimes tagged as the precur-sor of CEBs. Adobe blocks are usuallymade of a compacted mixture of clayand straw, however are less uniformin size and shape than CEB’s.

Cob construction does not involveblocks or bricks. Instead a mix of clay,sand and straw is made, then moldedand compressed into flowing formsto make walls and roofs.

Rammed earth construction entailsthe making of a mold into which thesoil, inclusive of a weatherproofing

agent, is compacted and left to dry.Subsequently, the mold is releasedand the earthen form remains.

Earth sheltering refers to the useof earth on the structure of a build-ing; it includes Earth berming, in-hillconstruction, and underground con-struction.

Wattle and Daub consists of awooden or bamboo frame laid ver-tically and horizontally reinforced onwhich earthen daub is packed.

Compressed Earth Blocks (CEB) are construction blocks made froma mixture of soil and a stabilizingagent compressed by different typesof manual or motor-driven press ma-chines. The Interlocking StabilisedSoil Blocks (ISSB) are a variation on

this.© UN-HABITAT/Adrian Perez

© James Morri

© University of Utah

© Vetsch Architektur AG




Soil stabilization refersto the application of ad-ditional supplements or

forces to the soil in orderto make it more water-proof and stronger. Thequality of the block de-pends on the propertiesand mix of soil types, theamount of force appliedfor compaction, and theaddition of chemical ornatural products to furtherstabilize and strengthenthe blocks.

The interlocks increasethe structural stability ofthe wall and reduce theamount of cement neededas mortar. The differenttypes of interlocks havedifferent structural pur-poses and architecturaluses.

The idea of making blocks by

compacting earth or mixing it

with stabilizing supplements is

an old concept dating back thou-

sands of years. Previously, and still

customary in certain parts of the

world, wooden molds are used

for making sun-dried or burned

earth blocks.

A key step in the evolution of

this technology was the creation

of the CINVA-RAM press in the

1950s by the Chilean engineer

Raul Ramirez for the Inter-Ameri-

can Housing Center in Bogota,

Colombia (CINVA). Since then,

the methods of producing earth

blocks has progressed resulting

in diverse types of motor-driven

and manual presses, and mobile

and industrial scale production

units.

Even though the CINVA-Ram and

other machines of this sort pro-

vided a more cost effective andenvironmentally-friendly solution

for block-making, some disad-

vantages remained. There was

still a need for masonry skills to

lay the blocks, as well as sig-

nificant amounts of cement for

mortar. The Human Settlements

Division of the Asian Institute of

Technology (HSD-AIT) along with

the Thailand Institute of Scientific

and Technological Research (TIS-TR) combined efforts for the cre-

ation of the first interlocking soil

blocks by modifying the CINVA-

RAM machine in the early 1980s.

This new wall construction tech-

nique reduced the use of cement

drastically, hence reducing final

building cost considerably, and

enhanced the structural stability

of the wall.

DEVELOPMENT OF ISSB TECHNOLOGY


Extensive research in appropri-ate technologies continues in re-

sponse to the increasing need foraffordable and environmentally-

friendly shelter options. Tech-

nological advances include newtypes of interlocks, alternativestabilizing supplements that can

be added to the soil and furtherimprovements to the press ma-chine. These technological devel-

opments allow for ISSB technol-ogy to become more competitive

due to increased productivity, amore user and environmentally

friendly profile, and an enhanced

cost effectiveness. In the early1990s, Dr. Moses Musaazi, fromMakerere University in Uganda,

developed a type of double inter-locking system and curved blocks

for the construction of watertanks.

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This mold is commonly used in rural areas for mak-ing of mud sun-dried or burned bricks. The fer-mented mud is thrown into the mold to avoid airgaps. However, the final product is not uniform.

The CINVA-RAM was developed after World War II,in a time of shortage and need to save energy. Itproduces uniform rectangular blocks.

This specific machine produces blocks with a doubleinterlock.

SSB TECHNOLOGY

ISSB TECHNOLOGY

ADOBE TECHNOLOGY



In East Africa, the manual Interlocking Stabilised SoilBlock machine is manufactured in Kenya. ISSB blocksare used for the construction of buildings, latrines,wells, septic tanks, and water tanks. This was the ma-chine used in all the case studies in this publication. The

main function of the machine is soil compression.Block quality is not so much defined by the machinebut by the quality of the raw materials introduced intothe mould, the method used for mixing them and themoisture content of the mix.There are many factors to be considered when choos-ing the most appropriate machine. Among these con-siderations are:» Affordability of end product » Type and scale of building structures

» Availability of construction skills » Availability of maintenance possibilities

» Reliability and cost of electricityThe manual machine is the most affordable optionfor block making and also the most convenient inrural settings due to the fact that it is manually oper-ated and easy to use.

ISSB BlocksDepending on the machine, different type of ISSBblocks can be produced:Straight Double Interlocking Block: The mostcommonly used block for wall creation.

Curved Double Interlocking Block: Used for mak-ing water tanks and sanitation facilities.

Wide Format interlocking Block: Allows for stron-ger, thicker walls, especially useful when makinghigh walls.Straight Single Interlocking Block: Contains alarger face, hence less blocks are needed to coverwall area. This was the predecessor to the straightdouble interlocking block.Grooved Double Interlocking Block: The groovesof this block facilitate plastering, however, this ma-chine is no longer produced.© UN-HABITAT/Adrian Perez

Technical specifications of the manual ISSBmachine used in East Africa:» Typical compression force: 80-100N » Weight: 140kg » 2-4 workers in an 8hr work day can produce

400-600 blocks

» Low maintenance: requires to be lubricated withengine oil.

» 130 stabilised blocks can be produced from a50kg bag of cement.

6

ISSB MACHINE



Plan Elevation Section





Straight DoubleInterlocking Block

Curved DoubleInterlocking Block

Wide FormatInterlocking Block

Straight SingleInterlocking Block

Grooved DoubleInterlocking Block

© UN-HABITAT/Adrian Perez© UN-HABITAT/Adrian Perez

The BLOCKS



PROCESS ANALYSIS for Cement-Stabilised Blocks

4 c m

4c m

6 0 c m

Make or buy a wooden boxwith the dimension statedabove and grease the inte-rior.

After the soil has dried, notethe shrinkage and record.When compared to the fulllength of the mold this ratiowill inform the amount ofstabilizer to be introducedinto the mix.

Fill the greased box with thesieved and moist soil to betested. Compact the soil har-dily into the mold. Leave themold to dry for a week in ashaded area.

?

Organic Matter

Divided soilparticles

Fill a bottle with 1/4 soil fol-lowed by 3/4 water

Shake the bottle vigourosly

Wait 30 minutes for the soilto settle. The heaviest parti-cles, gravels, will settle at thebottom followed by sands,silts, and clay at the top. Thiswill give you an idea of pro-portions of each particles inthe soil.

Sending the soilsample to a labo-ratory to run testsis another optionfor testing soilsuitability.

SANDS AND GRAVEL:Sands and gravels can be in-troduced into soils with toomuch clay content in orderto increase its density.

FIBROUS:Stabilization can be achievedthrough the introduction ofa fibrous reinforcer into thesoil mix such as dryed grass-es, animal hairs, or syntheticfibers.

SITE SUITABILITY

SEDIMENTATION TEST

SHRINKAGE TEST

LABORATORY TEST OTHER TESTS

For other tests,consult the “EarthConstruction Hand-book“ of UN-HABI-TAT.

Planning the pro-duction of ISSBsstarts with the

site and the prop-erties of the soilthere.

CHOOSING A STABILIZER

CHEMICALS & RESINS:At present there are manychemical stabilizers beingproduced specifically forcompressed earth block.There are natural resins andglues that can also be usedfor stabilization purposes.

CEMENT OR LIME:Cement is the most com-mon stabilizer used, how-ever it is not recommededfor soils with a high clay orsalt content. On the otherhand, lime serves very wellfor high clay content soils.



EXCAVATION

TRAINING OF LABOR FORCE

SIEVING

MIX PREPARATION

The making of ISSBs is a processbased activity; the steps leadingto good soil blocks must all be

carefully performed to ensurequality. Training normally takesone to two weeks.

Murram soil is recommended forthe making of cement-stabilizedblocks. This type of soil is foundat sub-levels. Therefore, onemust first remove the top soil toreach it.

The sieving process is importantin order to achieve good com-pact and smooth finish. To max-imize effectiveness allow sievedsoil to dry.

Once the cement-soil ratio is de-termined by using the shrinkagetest, mixing can start. This ratiois measured by the number ofwheel-barrows against one bagof cement.

MIXING

Upon mixing the dry matter, in-troduce water for wet-mixing.This will activate cement and in-stigate reaction.

MEASURING THE MIX

Depending on the soil mix, therewill be an optimum quantity ofit to be introduced into the ma-chine mold to ensure facility ofcompression and maximum den-sity.

Machine contains a stopwhich demarks full com-pression.

COMPRESSING THE MIX

REMOVING THE BLOCK

Stac oc s n ayers ofive and cover with grassor polythene paper. Fullcuring takes 28 days butblocks can be used before.

DRY AND STACK

Introduce a ully curedlock into a bucket of wa-er for a day to observets integrity and reaction.

When removing the block,check its texture and quali-ty. If unsatisfied, throw backinto the mix.

QUALITY CHECK




GENERAL INFO

InterlockingStabilised Soil Block

Sun-dried Mud Block Burned Clay Brick

Stabilised Soil Blockb

ConcreteMasonry Unit

Properties

BlockApperance

Dimension( L x W x H ) (cm)

26.5 x 14 x 10 cm25 x 15 x 7 cm to

40 x 20 x 1520 x 10 x 10 cm 29 x 14 x 11.5 cm 40 x 20 x 20 cm

Weight (kg) 8-10 kg 5-18 kg 4-5 kg 8-10 kg 12-14 kg

Texture Smooth and flatrough andpowdery

rough andpowdery

smooth and flat coarse and flat

PERFORMANCE

Wet CompressiveStrength (mps)

1 - 4 0 - 5 0.5 - 6 1 - 4 0.7 - 5

Thermal Insulation

(W/m C)

0.8 - 1.4 0.4 - 0.8 0.7 - 1.3 0.8 - 1.4 1 - 1.7

Density (kg/m3) 1700 - 2200 1200 - 1700 1400 - 2400 1700 - 2200 1700 - 2200

Per Block (UgS) 350 50 150 400 3000

AVG. PRICE (2009)

Per Sq Meter35000 10000 55000 45000 75000

WallApperance

(not rendered)

Blocks needed tomake up a sq.m.

35 10 to 30 30 21 10

COMPARATIVE ANALYSIS and ADVANTAGES OF ISSB

The advantages of ISSB technology are many and even when compared to other technologies; it is affordable,

environmentally sound, user friendly, performs well, versatile in use, among others. However, like with any other

construction technology, care must be taken to ensure quality. The quality of ISSB’s depends on good and locally

available soil selection, a stabilizer to compliment the type of soil, and good practices during production and imple-

mentation.

Information for this chart gathered from Craterre publication: “Compressed Earth Blocks :Manual of Production” and GET



ENVIRONMENTAL

H E A

L T H

E C O N O

M I C A L

E A S Y T O U

S E

A E S T H E T I C S T R U C T U R A L

E D U C A T I O N A L

ENVIRONMENTAL:

ISSB technology pro-vides an alternative tothe commonly used firedbrick in Uganda, whichcurrently is the cause

of grave environmen-tal degradation due to

deforestation, and de-struction of wetlands.

HEALTH:

The curved ISSBs are

ideal for meeting waterand sanitation needs.The curved ISSB canmake water tanks, lin-ing for pit latrines, andseptic tanks. There

are samples of above-ground water tanksof up to 30,000 litersand below-ground ofup to 200,000 lts. Thefinal cylindrical shapeof the structure andthe block interlockingmechanism resists wellagainst water pressure.

ECONOMICAL:

ISSB technology is anaffordable way of con-struction. The bricks areweatherproof hence,there is no need to plas-ter the building exterior.Also, due to its interlock-

ing mechanism, little ce-ment is needed betweenblock joints and wallconstruction goes upquickly allowing for la-bor savings. The machineitself weighs 140kg,making it in cases, easyto transport and workwith onsite construction.

EDUCATIONAL:

As a new technol-

ogy, this constructionmethod can increaselocal skills and becomean income-generatingopportunity for variouspopulations. It is easy tolearn and can stimulateeducational dialogue re-garding environmentalissues due to its nature.

STRUCTURAL:

ISSB technology hasproven to be strong anddurable when comparedwith traditional methodof construction. It issuitable for multistorybuilding, has a goodcompressive strengthand in many exampleshas been used for the re-

taining wall of buildings.

EASY TO USE:

The ISSB machine iseasy to use and to main-tain. After long use,repairs can be madelocally through scrapmaterial and welding.

Due to the interlock-ing mechanism of the

blocks, wall construc-tion is much easier andquicker.

AESTHETIC:

ISSB technology isgrowing in popular-ity due to its aestheticqualities, and has beensuccessfully embracedby many communitiestrained on it. Also, inview that it is an earthtechnology, as most ofthe common and tradi-

tional methods used inUganda, it is not foreignto local communities.

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Burned bricks are some of the most common construc-tion methodologies used in urban areas. In rural areas,wattle and daub still dominates rural construction inparticular for the poor. For many people, a house madeof burned bricks is accorded higher status than onemade of sun-dried mud blocks or through wattle and

daub.

Clay Extraction

Unmonitored soil extraction is damaging to the environ-ment and nearby communities. Burrows left unattend-ed create pools of stagnant water, providing breedinggrounds for mosquitoes, fuelling the spread of malaria.Large scale clay extraction also decreases usable landfor agriculture.

Deforestation and Firing

The traditional method for burning bricks in Uganda

consists of stacking a large amount of dried bricks (upto 20,000) into a large pile with a tunnel opening atthe bottom into which large quantities of firewoodare introduced and burnt during 24-hours. The pile isplastered with mud in order to reduce heat leakage.This process results in unevenly baked bricks and 20%waste as the bricks closest to the heat source are overburned while those farther away are under-fired.

The large quantities of firewood needed for firing brickscontributes to deforestation, which affects biodiversity.It contributes to air pollution, soil erosion and degra-dation, desertification of the landscape, and reducesavailable fuel sources for other human activities. In

agricultural regions, these consequences are especiallydetrimental and contribute to the food crisis and some-times fuel conflict over the limited resources.

Currently, there are attempts by various organizationsto raise awareness on alternative fuels and kiln con-struction in order to increase production rates and re-duce environmental impact.

Excessive use of mortar

Burned bricks are mostly uneven in size, requiring upto 3 centimeters of cement between each brick. Sincethe walls are not aesthetically pleasing, they are often

plastered over which increases the final building costsignificantly.

Clay Extraction

Firing

Excessive use of mortar

Deforestation

CONSTRUCTION IN UGANDA: Burned Bricks

Economy: Unit cost is limited, however, due to theamount of cement needed for mortar and plaster, thisconstruction methodology turns out to be expensive.

Durability: Burned bricks make for durable structures.

Environment: Due to the deforestation and excessiveclay excavation involved, burned bricks are environmen-tally detrimental.

Resistance to Elements: Strong

© Manuel Scrima

© Manuel Scrima

© Manuel Scrima

© UN-HABITAT/Caylee Hong12



Adobe or sun-dried mud blocksare a common method of con-struction in the rural areas and arealso used in camps for displacedpeople. They are environmentallyfriendly. The final aesthetic qual-

ity of using sun-dried mud blocksis however considered unpleas-ant. In addition, there is a needto plaster to extend building life.Plaster techniques are, amongstothers sand with mud and a spe-cial cassava mix with sand. Directplastering with cement is expen-sive and degrades quickly due tothe weak adhesion between clayto cement.

Economy: Considering thatthe main raw material is mud,this type of construction is veryaffordable. Final cost varies de-pending on the plaster used.

Durability: If well maintainedand plastered, the building canhave a long life.

Environment: There is littlewaste or energy involved mak-ing it an environmentally friend-ly technique..

Resistance to Elements: Weakto medium

Wattle and daub is a common prac-tice for low cost housing in Uganda.Plastering is often used to embellishthe structures and to extend the lifeof the building.

Cement consumption patternsin Uganda have been steadily in-creasing for the past decade. Thistype of construction is mainly usedin urban areas.

Economy: Concrete construc-tion tends to be expensive.

Durability: Concrete struc-

tures are long-lasting.

Environment: A lot of energyis needed to produce cement.

Resistance to Elements:Strong but weak insulation ca-pacity.

Economy: Raw materials arereadily available, hence its lowcost.

Durability: In view that thedaub is not densly compacted,wattle and daub structures re-quire high maintenance henceaffecting the building life.

Environment: Use of wood forthe structure results in defores-tation.

Resistance to Elements:Weak




Wattle and daub

Concrete

Adobe



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ISSB CASE STUDIES: UGANDA



TEACHERS’ HOUSING LIRA

UN-HABITAT:

The mission of UN-HABITAT isto promote socially and envi-ronmentally sustainable humansettlements and to work to-wards adequate shelter for all.

Project Abstract:

UN-HABITAT, with funding fromUNICEF, implemented this proj-ect to facilitate the sustain-able return and reintegrationprocesses in Northern Uganda.Through the use of alternativeenvironmentally-sensitive build-ing technology, 64 teacher’shousing units in 16 schools andthree ISSB demo buildings wereconstructed in the area.

Structure:

» 16 ISSB buildings each con-taining four unit housingblocks

» 16 ISSB two unit VIP-Toiletblocks

» 32 unit kitchens made by thebenefiting community

» 3 demo offices, one contain-ing an ISSB water tank

Type of Block Used:

» Single Interlock » Double Interlock » Grooved Double Interlock

Contextual Innovations

» The use of ISSBs at founda-tion level in form of a doublewall.


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» The machines used were pre-viously non-interlocking. Localwelders were commissionedto modify the machine moldsfor the production of inter-

locking blocks.» For the wall construction of

the kitchens, the benefitingcommunities used unstabi-lized interlocking compressedsoil blocks made with the ISSBmachines. The use of sun-dried clay soil blocks is a com-mon practice in the area.

» Tender documents developedfor use of ISSB by the privatesector allowing further stan-dardization.

Challenges

» Mobilizing communities toparticipate in the project.

» Sensitizing the community onappropriate technologies.

» Ensuring quality control ofblocks produced.

Lesson Learned

» Intense supervison is neededat the start of the project toensure block quality.

» Use of better quality murramtaken from more remote loca-tions instead of using local soilincreases final cost.

» Incorporating indigenous con-struction knowledge leads toinnovations and sustainability.

Promoting the Technology

»

Working with private sector(local contractors and ma-sons).

» Developed a system of lendingthe ISSB machines and provid-ing training to interested localcommunity and private devel-opers based on an agreementguaranteeing the use of themachine.

» The construction of ISSB demobuildings as resource centers.

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PAJULE SECONDARY SCHOOL

ARUP

This consulting engineering firmis one of Ireland’s largest. Theirwork is characterized by inno-vative and sustainable designsolutions, and value-engineer-ing projects. Through the ArupPartnership Worldwide, thereare over 10,000 staff working

in more than 90 offices in 37countries. Project Abstract

The school is located near Pajuletown in Pader, Uganda. Thisarea currently houses one of thelargest IDP camps in the country.The purpose of the project is toprovide a school building and acampus for the Pajule SecondarySchool which currently shares

its premises with the primaryschool. The new school campuswill decongest the existing situ-ation and provide the studentswith a quality environment con-ducive to learning.

Structures:

Phase I:

» Two classroom blocks» Two Latrine blocks

Upcoming Phases:

» Classroom blocks» Library » Admin Building

Type of Blocks Used:

» Wide Format Double Inter-lock

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» As a way of hiding the conven-tional exposed concrete ringbeam, a U- block was developed

by fitting a timber piece into themachine to change one of itsfaces. This U-block containeda larger depressed interlock, inwhich the ring beam could beconcealed.

Challenges

» No.2 type machines used toproduce wider blocks neededmore maintenance and repairs

» At the start, block production

was slow as a result of the fol-lowing:

• Due to the rainy season, themurram soil used was wet,making it difficult to sieve.

• Labor force was new to thetechnology however, speed in-creased with time and practice.

• Availability of suitable soil forblock making.

• Lack of design and technical in-formation.

Lesson Learned» Block production is slow when

murram is wet. » No.2 type machine needs to be

made more robust. » Well made blocks have a good

finish. » Wall construction is quick. » More design information is re-

quired for more complex struc-tures.

Other appropriate technologies

» Rain water harvesting fromthe roof.


» Employing local labor force forblock making and wall con-struction.

» Donating ISSB machines to thelocal community for further use.

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WATER TANKS in Luwero

CARITAS Kasana-Luwero CKL:

CKL is the regional branch of afaith-based organization “aim-ing at contributing to the social,political, and economic devel-opment of the masses throughvarious programs and projectsthat lead to self-sustained devel-opment of the individual house-hold in our communities. Sincethe adoptions of ISSB technol-ogy by this organization eightyears ago, they have proactivelyconstructed over 600 watertanks in their region, residen-tial quarters within their com-plex, and a number of homesthrough a self-developed homefinancing pilot program.

Project Abstract:

CKL developed a regional pro-gram for the provision of watertanks for the local communities.This organization practices costsharing mechanisms with thehousehold or institution inter-ested in a water tank. The in-terested party is required to pay20% of the tank price as well asprovide the raw materials (mur-ram, sand, cement), which theCKL provides the trained ma-sons and technical advice. Structures:

» Water tanks


» Curved Double Interlock

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» The development of commu-nity programs which enhance

quality of life.

Challenges

» Receiving unsuitable raw ma-terial from the benefiting par-ties.

» Devising methods of increas-ing individual and/or organi-zational ownership of project.Lack of technical data.

Lesson Learned

» Over the years, ISSB technol-ogy has proven to be a soundmethod of construction forwater tanks.

» Benefiting parties must besensitized regarding raw ma-terial quality.

» If well made, the blocks areweather-proof, hence do notrequire plaster.


» Promotion through projectimplementation.

» Providing ISSB training. » Loan machines to aid regional

development.

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CONNECT AFRICA RESOURCE CENTERS

Connect Africa:

Connect Africa is a Ugandan faith-based organization promoting andproviding local residents with ap-propriate technologies and trainingto create sustainable communities.

Project Abstract:

Connect Africa’s activities revolve

around “Connect Africa ResourceCenters” (CARCs) that serve as abase for training and technologi-cal dissemination. At these ISSBcommunity-constructed centers,Connect Africa teams teach localleaders how to use sustainable tech-nologies that in turn help raise thelocal residents’ quality of life. Cur-rently there are four CARCs, all lo-cated in strategic areas in NorthernUganda including Kigumba, Opit,and Atiak; the recently constructed‘hub’ located near Kampala. Structures:

» Each CARC holds a confer-ence room and living quartersfor volunteers

» ISSB water tank(s) & water filters» ISSB production unit» ISSB Ecological Sanitation toilet

(Eco-San)


» Double Interlock» Curved Double Interlock


» The CARC built in Opit four yearsago was made of dry-stackedISSB blocks and has proven soundso far and cost effective.

» The left-over and unusable ISSBblocks have been used for thecreation of a ‘Rocket Stove’.© UN-HABITAT/Adrian Perez

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These stoves are made from re-cycled oil drums and discard-ed ISSBs which successfullycontain the heat for cookingaround all sides of the pot.

This process uses approxi-mately 1/7th of the fuel usedin traditional stoves, requiresless wood for burning, andreduces fire accidents.

Challenges

» Lack of design and technical data» Transportation of machines. » Re-use of the cavity after soil ex-

cavations.

Lesson Learned

» Need to plaster building up towindow level to avoid block wear

» Ensuring a good structural con-nection between the roof andthe wall to avoid collapse due tostrong winds.

» Need for design and technicaldata to aid in construction.

» It is cost effective to build withISSB technology.

» Local communities can be easilytrained in block production.


» Each CARC contains on-site anISSB Eco-San toilet. This technol-ogy provides an alternative to ‘pit-latrines’ which contaminates theunderground water tables. Thistoilet contains an above groundcollection tank to turn waste intocompost and fertilizer.

» The CARCs in Northern Ugandamanufacture and distribute the

Bio-Sand Water Filters for treat-ing harvested water.


» Imparting vocational trainingsand workshops on ISSB Technol-ogy to local communities.

» Using community labor force forthe construction of the CARCs.

» Disseminating informationthrough community leaders us-ing the concept of circles of in-fluence.

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LORD MEAD’S VOCATIONAL SCHOOL CAMPUS

Haileybury Youth Trust:

HYT works with communities toimprove quality of life by meet-ing humanitarian needs, suchas housing, education, and ac-cess to clean water in an en-vironmentally friendly manner.

HYT provides training programsand advocates ISSB technolo-gies. HYT has been involvedin over 20 ISSB projects in theJinja area building water tanks,affordable teachers’ housing,classrooms, perimeter walls,dormitories, and schools.

Project Abstract: The most comprehensive proj-

ect taken upon by this orga-nization is the developmentand expansion of Lord’s MeadeVocational School containingwithin its campus samples ofall the previously mentionedstructures.

Structures:

» Water Tanks » Dormitory building

» Teachers’ housing(bottom left)

» Double Classroom Block » Store » Bench (top left)


» Double Interlock » Grooved Interlock » Curved Double Interlock


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» HYT developed an ISSB train-ing program for the youth ofLord’s Mead Vocation School.

The students trained in ISSBtechnology were encouragedto make blocks which wouldbe used in the school’s con-struction projects. They re-ceived a small allowance, perblock made, helped studentsto pay school fees, buy sup-plies, or mostly served as ex-tra spending money.

Challenges

» Coping with communityskepticism regarding the newtechnology.

» Developing ways to increaseindividual or community own-ership of the projects.

Lesson Learned

» Introduction of ISSB voca-tional training into a school’s

curricula is a successful wayof achieving adoption of newtechnology and ensuring itsuse in the future.

» Technology skepticism can bereduced through constructingvisible community structuressuch as benches.


» Providing ISSB training to lo-cal communities, especially

the youth. » Promoting the technology

through project implementa-tion.

» Dissemination of informationto relevant stakeholders.

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MAKERERE UNIVERSITY Sports field

Presidential Initiative toSupport Appropriate Tech-nology PISAT- under UgandaNational Council of Scienceand Technology UNCST:

The UNCST Vision is “to bethe centre of excellence forthe management and integra-

tion of science and technologyinto the national developmentprocess.

The UNCST Mission is “to pro-vide effective and innovativeleadership in the development,promotion and application ofscience and technology and itsintegration in sustainable na-tional development”.

Project Abstract

The project objective was touse ISSB Technology to helptransform the Rugby pitchinto a quality field site, com-plete with toilets, seating area(stands) and a club house withlocker rooms, dining area andVIP area.

Structures:

» Toilets » Stands- seating area » Retaining Wall-

Perimeter wall » ISSB Water tank


» Double Interlock» Curved double interlock© GET/Lisa Baumgartner

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» The technology is being usedto build a retaining wall

along the back side of thefield. In order to accomplishthis, blocks were made witha higher proportion of sandthan soil in order to producestrong blocks that can also beleft un-plastered. The retain-ing wall is made using a dou-ble layer of ISSB blocks withsteel reinforcement, bothhorizontally placed along theinterlock and vertically tyingthe two walls together, pro-

viding added strength to thewall.

» The conventional concretelintel was substituted by re-bar at that level.

Challenges

» The main challenge was tomake the wall strong enoughto serve as a retaining wall.

Lesson Learned» ISSBs can be made strong

enough for use in more struc-turally demanding situations.


» Visibility- identifying institu-tions and places where peo-ple can see the technology.

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St. KIZITO PRIMARY SCHOOL

BULA inc.(Better Understanding Life in Africa)

BULA’s mission is to secure brighterfutures for African youth througheducational support and communitydevelopment. The construction ofSt. Kizito Primary School is the firstISSB project completed by BULA.

Project Abstract:

St. Kizitio Primary School is locatedin the outskirts of Kampala in Ggan-da. The vision and execution of theproject was a collaborative effort ofthe school management, local lead-ers, and BULA. By engaging the lo-cal community, BULA initiated andmanaged the reconstruction of thisschool. Supplies and labor wereprovided by the community. Thepurpose of this project was to firstlyprovide the children with propereducational facilities for learning

and additionally, to strengthen theties and organizational skills of thecommunity.

Structures:

» 8 ISSB classrooms; Nursery to P7(150 Students)

» Two ISSB teacher offices and astaff room

» A 30,000 gallon undergroundwater tank and a 5000 L aboveground tank

» Solar powered lighting

» Toilet facilities » A kitchen


» Double Interlock


» The cavity left due to soil exca-vation became an underground30,000 gallon water tank for theschool and community© Manuel Scrima

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Challenges

» Importing of some murram toensure block quality due to thehigh levels of the clay in the soilon-site.

» Supervising of newly trainedblock-making/laying crew to en-sure block quality and use of ce-ment during wall construction.

» Lack of technical informationregarding wall construction andblock production leading to trialand error solutions.

» The two machines hired for blockmaking produced blocks thatvaried in quality and size.

» The machine required constantmaintenance with regards to lin-ing of PVC and oil to prevent thesoil from sticking.

Lesson Learned

» Need for close supervision at theearly stages to ensure qualitycontrol.

» Building with ISSB technology istime-effective; the project wascompleted in 5 months

» A good use of the cavity leftafter soil excavation as an un-derground water tank and pit

latrine » Using mostly local labor increasescommunity pride and ownershipof the project


» The light of this complex is pow-ered by solar panels on the roof.

» All of the harvested rain water istreated through the use of Bio-Sand water filters. The schoolhas developed a system for wa-ter treatment using color-coded

containers: yellow for untreatedwater, blue for clean water.


» Employing local community laborforce and introducing the technol-ogy to local leaders and officials

» Commitment to use ISSB tech-nology for future schools andconstruction projects

» BULA promoted awareness via theinternet and through communityand youth awareness programs

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MAKERERE UNIVERSITY: Laboratory

Centre for Research in Ener-gy and energy ConservationCREEC

The goal of CREEC is to createcapacity in all fields related toenergy with a special focus onenergy management, solar pho-tovoltaic, hydropower, and bio-

mass.

The aim is to develop technolo-gies and systems that have a di-rect, positive impact on people’severyday lives.

Project Abstract:

To strengthen CREEC’s effortsin the field of biomass energyand to improve their research

facilities, this new laboratoryspace was constructed. It willbe called the Biomass ResearchCentre. In addition to testswith biomass and fuel-efficientstoves, the facility will be usedto test and validate electricalmaterials and equipment for lo-cal markets, in conjunction withthe Uganda National Bureau ofStandards.

Structures:

» Laboratory Facility » ISSB Water tank


» Double Interlock » Curved Double Interlock

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» The Labs make use of naturallight by adding in some clearplastic sheets as roofing ma-

terial

» Since this will be a lab andtesting facility of fuel-efficientstoves, special ventilation hasbeen catered for on the sidesof the building

Challenges

» The main challenge was en-sure quality control of theblocks

Lesson Learned

» There was an easy skills trans-fer in terms of masonry skills.

» There was a cost savings of30%

Promoting the Technology » Promotion of the technol-

ogy through project imple-mentation

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LESSON LEARNED

© UN-HABITAT/Caylee Hong



Standardization required Technical data of ISSB technologyis still insufficient, leading to skep-ticism of the technology amongst

construction industry profession-als. The technology has not yetbeen standardized in Uganda.The Good Earth Trust is coordi-nating with the Uganda NationalBureau of Standards to producestandards for ISSB technology fol-lowing the Kenyan example. Thisis expected to be finalised in 2009.In order to ease the integration ofISSB technology into more dense-ly-populated urban areas, thereis a need to produce more tech-

nical data including quality testsand appropriate building codesand standards. Standardizing andpublicizing technical data is essen-tial to promote use amongst pro-fessionals in the building industry.Sufficient technical data shouldalso help to promote buildingtechniques maximizing the advan-tages of ISSB, instead of using ISSBin conventional ways (e.g. withmortar instead of a fitted joint).

3.2.3 Education

Ignorance, lack of access to information, and education on environ-mental topics, especially those related to sustainable construction, arepresent at all levels. Raising public awareness on environmental andequity issues is indispensable for sustainable development. For success-ful implementation of comprehensive and appropriate developmentissues, it is essential to educate the public, governments, social andtechnical institutions and business groups about comprehensive sus-tainability issues. Just as an individual understands the implications ofhis daily financial decisions, similarly he should be cognisant of the so-cial and environmental implications of his actions.

Two main problems exist in the current education system. The firstand most important one is a lack of integration of these efforts withinthe education system, since development as well as research in thefield of sustainable human settlements and construction is not linkedto the academic institutions. At best, any change and developmentwork continues to remain one of many pilot projects or “alternative”options. Their propagation at a mass level is hindered by the lack ofappropriately trained professionals within the profession, governmentagencies and amongst the educators themselves. This lack of aware-ness also exists amongst the general public.

Agenda 21 for Sustainable Construction in Developing Countries

Integration into educationalcurricula needed

ISSB technology has not been in-tegrated into the educational cur-

ricula of secondary vocational in-stitutions and tertiary engineeringand architectural institutions. This isthe most effective way of ensuringthe technology’s use in the future.At present, one of the key challeng-es is changing the mentality of thecompanies and individuals alreadymanufacturing and using the con-ventional methods of constructionsuch as burned bricks and con-crete blocks. Due to their popular-ity, graduates of different educa-

tional programs are being trainedto suit the needs of the industry athand. As a new technology, ISSB istherefore at a disadvantage due tothe lack of trained professionals.In order to increase and ensure fu-ture use of ISSB technology, espe-cially in urban areas, more youngprofessionals need to be trainedin its use. In addition, introducingISSB education into the curriculawill encourage further research.

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Research to be extended

Alternative stabilizers and soil mixturesThe most common method of mak-ing the blocks is through the mix ofcement or lime (stabilizer) and mur-ram soil, compressed in the ISSBmachine. However, in areas where

insufficient amounts of murram areavailable and cement or lime provesto be to expensive, affordability canbe a problem. There are severalother potential stabilizers and soilmixes, which after compression canproduce structurally-sound, cost-ef-fective, and environmentally-friend-ly soil blocks. Compression itself isalready a stabilizing agent.

Facilitating transport of ISSBmachines

The ISSB manual machine is themost cost-effective and accessibleway of making soil blocks. None-theless, there is potential for furtherdecreasing its costs and facilitatingits use. In rural areas with limited ac-cess, transportation of the machinewas challenging due to its weight(140kg) mostly necessitating mo-torized transport. Some have man-aged to transport it by bicycle, us-ing a number of people to slowlyguide the bike to the construction

site. Ways need to be explored toincrease mobility of the machine byfacilitating for instance, easy dis-mantling and re-assembling.

Adaptable wall construction A common challenge found withISSB technology, similar to otherconstruction techniques, is the in-troduction of the electrical andplumbing systems. In most cases,walls have to be chiseled in order

to allow these systems to traversethe building. New architectural de-sign techniques or adapted inter-locking block types could be devel-oped.Building stability in earthquake-

prone regions needs to be improvedthrough, amongst others, the intro-duction of vertical rebar. Research isongoing at Makerere University inUganda.

Need for adaptable blocksThe interlocking mechanism re-duces the necessary time for wallconstruction. However, for corner,intersecting and Y wall connec-tions, there is a need to break theblock. By making a machine mold

with additive pieces to change finalblock shape, there ceases to be aneed to break the blocks after cur-ing. Alternatively, a block-slicingapparatus could be developed forbreaking the block before the cur-ing process in order to maintain aneat final finish.

Need for alternative plasteringtechniquesIn Uganda, it is common to plas-ter the building walls with cement,

which is expensive and unafford-able for low-cost housing. More re-search is needed to provide popula-tions with effective, affordable andenvironmentally friendly techniquesto protect walls against wear andtear.

Using ISSB for other buildingelementsCurrently, the use of ISSB technol-ogy is mostly restricted to buildingwalls and water tanks. In customaryshelter construction in Uganda andother countries, the wall is not themost expensive building compo-nent. The roof generally makes upto 50% of the final building cost,and the foundation is the most la-borious activity. For roof construc-tion, ISSBs could be used in the con-text of arches, vaults and/or domes.As for the foundation, there arealready examples in Uganda wherestrengthened ISSBs have been usedfor the retaining wall.

Local economic developmentmodels to be explored

There is a need to further sensi-tize community groups and vul-

nerable communities in regardto business and self help oppor-tunities using ISSB.

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Further improving affordability Compared to other constructionmethods such as burned brickand concrete block construction,

ISSB technology has proven tobe less expensive if implementedcorrectly.» Most savings are attributed to

the reduced use of cement mor-tar needed between the block

joints due to their interlockingmechanism. In addition, theinterlocking mechanism allowsfor faster wall construction,resulting in labor savings. Firsttime use of the technology canbe time consuming, however,

time saving comes with prac-tice.

» There is no longer a need tofully plaster the building walldue to the neat block finish andits weather resistance. Properdrainage systems and roofoverhangs can help to protectthe walls.

» ISSB technology allows for on-site construction which reducescost for transportation.

» In order to ensure cost-effec-tiveness with cement stabilizedblocks, soil selection and test-ing are fundamental. The bet-ter the soil, the less cementhas to be introduced into themixture.

» Blocks made from the wide for-mat machines are more expen-sive due to the fact that morematerial is used per block andshould only be used where theadvantages outweigh the cost.

»

Alternative stabilisers, replac-ing cement in the mixture,could help to further reducethe cost. The cost per squaremeter for ISSB is still too expen-sive if compared with the tra-ditional techniques used in ru-ral areas. However, the use ofcompressed soil blocks withoutadditional stabilisers alreadyprovides improved construc-tion techniques.

Need to consider timing

Avoid the rainy seasonSome seasons will be betterthan others to produce blocks.

During the rainy season, the wetsoil makes it harder to sieve, re-quiring additional measures.Sieving is an important processin the production of ISSB. It fa-cilitates compression and ulti-mately makes for more compactand sturdy blocks.

Align with agricultural sea- sonsThe agricultural cycles must

be respected. Right before therainy season, all efforts of theagricultural society are mainlyinvested in planting; there islittle construction during thistime. Most traditional construc-tion happens during the dry sea-son when the crops have grownto full size and are ready to bedistributed.

Building on indigenousknowledge

It is important to take into con-sideration the tacit local knowl-edge to ensure the technolo-gy’s adoption. In Uganda, theuse of earth is already a conven-tional method of constructionwidely used throughout thecountry and affected popula-tions have a good understand-ing of the use of certain typesof soils for traditional blockmaking. This creates the oppor-tunity for ensuring sustainabilitywith respects to the successfulintegration of the technology.An area assessment evaluatinglocal resources and traditionalconstruction techniques shouldbe performed before new tech-nologies are introduced, look-ing at the raw materials avail-able, local skills, and indigenousmethods of construction.

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Further promoting the technol-ogy with different stakeholders

There is a need to elevate theprofile of the technology, It is

increasingly categorized as abuilding material for low-costhousing and consequently mis-taken as low-quality. Using thetechnology in more ostentatiousprojects will help to challengethese assumptions.

Local culture and traditions mayaffect the attitude towards ISSBtechnology and the generalcomprehension of processes in-volved in block production and

use. The technology should bepromoted in a culturally- re-sponsive way, so as to promoteits use also in self help construc-tion.

The private sector plays a keyrole in expanding the use ofISSB technology in Uganda. Atpresent, there are still too fewcompleted examples of ISSBstructures built by the private

sector, especially in the urbanareas. This is partially due to thefact that standardization hasnot been fully achieved. Thereis a need to promote environ-mental principles in the privatesector alongside arguments ofcost and time efficiency. Asidefrom adding legitimacy to thetechnology, it will support sus-tainable urbanization as the pri-vate sector is the main actor inconstruction.

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More networking amongststakeholders

There are a variety of groups us-ing ISSBs in Uganda, each build-

ing up their own experience withthe ISSB technology. There isa need to develop informationsharing mechanisms in order tofacilitate further improvementsand the further spread of thetechnology. A database of ISSBprojects is being established.Good Earth Trust intends to serveas a hub for guidance and advo-cacy.

Need for quality control

Malpractice with ISSB can easilylead to the technology’s demo-tion. Consequently, it is crucial toprovide users of ISSB technologywith more accessible resourcesand appropriate knowledge re-garding block production anduse. Ways of ensuring projectquality should be developed.This includes extended trainingand monitoring, more accessible

literature and information, or es-tablishing a network of success-ful ISSB users per region.

Use of ISSB in crisis affectedregions Due to the higher environmentaldegradation, reduced availabil-ity of traditional materials, andthe urgent need for construc-tion materials in post-conflict

and disaster regions, appropriatetechnologies that make use ofimmediate local and more en-vironmentally friendly resourcesare most suitable in this context.ISSB technology has proven suc-cessful with respect the recov-ery and reconstruction efforts inpost-conflict areas of Uganda. Italso provides an opportunity for

job creation in the affected re-gions.

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WAY FORWARD




STANDARDIZE

RESEARCH

CONTEXTUALIZE

WAY FORWARD

» Finalize the creation of National Standards and generic tenderdocuments, allowing diverse use of the technology taking intoaccount affordability.

» Produce a maintenance and construction manual. » Liaise with Ugandan Ministry of Education for the introduction

of ISSB technology into vocational training colleges and tertiaryeducational institutions.

» Development of educational modules to aid in the teaching ofISSB technology in vocational and tertiary insitutions.

Encouraging further research and experimentation in thefollowing areas:

» Alternative environmentally friendly plasters. » Alternative stabilizers for soil mixture. » Increasing transportability of the machine. » Use of ISSBs in other building elements such as roof and

foundation. » Develop ISSB specific architectural details.

» Develop a standard method of assessing an area prior to ISSBtechnological deployment.



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EDUCATE

MONITOR

PROMOTE » Develop culturally responsive promotional approaches in-cluding manuals in the local languages, and establish re-source centers in strategic locations.

» Increase awareness of alternative stabilization processes

to make the technology more contextually flexible, easilyimplementable in a range of diverse settings and making itmore affordable.

» Promote the use of ISSB technology in more ostentatiousprojects to showcase its qualities.

» Augment promotion efforts of the technology in urban ar-eas through the private sector.

» Develop business models for the development of incomegenerating activities using ISSB technology.

» Create special programsmes for the conversion of the burntbrick producers.

» Increase efforts to monitor the various projects using ISSBtechnology in order to ensure correct implementation andto record best practices for furthering the technology’s de-velopment.

» Increase levels of awareness amongst the community atlarge with respests to appropriate technologies and sus-tainable living.

» Teaching through project implementation such as demoprojects,

» Build capacity at all levels. » Introduce ISSB technology into the educational curricula.




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Books and Publications

Andabati, D. (2009). Construction Manual.Double Interlocking Rectangular Blocksfor House Construction. Good EarthTrust.

CIB & UNEP-IETC. (2002). Agenda 21 for

Sustainable Construction in Develop-ing Countries, A discussion document.Pretoria: CSIR Building and ConstructionTechnology.

Guillaud, H., Joffroy, T. & Odul,P. (1995).Com-pressed Earth Blocks :Manual of Designand Construction. CRATerre-EAG, Ausder Arbeit von GATE. Germany:Braunsch-weig Vieweg.

Rigassi, V. (1995).Compressed Earth Blocks :Manual of Production. CRATerre-EAG,Aus der Arbeit von GATE. Germany:Braunschweig Vieweg.

UN-Habitat.(1992). Earth Construction Technol-ogy. Nairobi: UN-Habitat.

Yager, T. (2004), The Mineral Industry in Ugan-da. U.S. Geological Survey, National Cen-ter:Virginia.

Articles

Prussian, Labelle. (1974). An Introduction toIndigenous African Architecture. TheJournal of the Society of ArchitecturalHistorians, Vol. 33, No.3, 183-205.

Online periodical and publications

CRATerre Editions. (2005). Earth Architecture inUganda: Pilot Project in Bushennyi. On-line: www.craterre.archi.fr.

Deutsche Zentrum für Entwicklungstenchnolo-

gien-GATE. (1991) The Basics of Com-pressed Earth Blocks.Online: www.basin.info/publications/books/Basics_of_CEB.pdf.

International Strategy for Disaster Reduction.(2008) Indigenous Knowledge for Disas-ter Risk Reduction: Good Practices andLessons Learned from Experiences in theAsia-Pacific Region. Online: www.unisdr.org

Maïni, Satprem. Earthen Architecture forSustainable Habitat and CompressedStabilized Earth Block Technology.Re-trieved March 2009 from www.aurovile.info/ACUR/documents/envi_urb_pres/sat-prem_cpdc.pdf.

Practical Action. Alternative to Portland Ce-ment, A technical brief.Retrieved March,2009 from www.practicalaction.org

Practical Action. Mud as Mortar, A technical brief.Retrieved March, 2009 from www.practica-laction.org

Weinhuber, K. (1995). Building with Interlock-ing Blocks. German Appropriate Technol-ogyExchange. Retrieved March 2009 fromwww.fastonline.org

Other

Good Earth Trust. (2009). Good Earth TrustISSB Project Database. Uganda.

Perez, Adrian.(2009). Mission Report, ISSBTechnology in Uganda. Disaster Manage-ment Programme. UN-Habitat

UN-Habitat Regional Office Lira (April 2009).ISSB Workshop Lira. Uganda

FURTHER READINGS



INTERLOCKING STABILISED SOIL BLOCKSAppropriate earth technologies in Uganda

Interlocking Stabilised Soil Block (ISSB) technology has beengaining recognition, particularly in East Africa. This materialand method of construction has the advantages of low cost

and minimal environmental impact, while providing compa-rable quality to conventional fired brick construction. With agrowing number of organisations using the technology thereis a need to improve communication and knowledge-sharing,to quantify and verify the benefits, and to develop efficientapproaches for its promotion and adoption.

The purpose of this publication is to promote the use of ISSB bysharing some case studies of successful adoption and adapta-tion to local contexts. It also highlights some of the challengesfaced in developing and promoting the technology with somekey lessons learned from projects in northern Uganda. Thisdocument provides stakeholders interested in the sustainable

development of human settlements with a reference tool foran innovative construction method in practice.

HS/1184/09EISBN: 978-92-1-132150-0

UN-HABITATP. O. Box 3003000100 Nairobi

GPO KENYATel: 254-20-7623120Fax: [email protected]

Printing: UNON, Publishing Services Section, Nairobi,ISO 14001:2004-certified