low cost construction

LOW COST CONSTRUCTION

TECHNIQUES

PROPOSED TECHNIQUES

&

LITERATURE STUDIES

FUNICULAR ROOF

FUNICULAR ROOFS-AN ALTERNATE TO RCC ROOFSTHE FUNICULAR SHELL ROOF IS ONE SUCH COMPRESSION STRUCTURE, WHICH ENSURES CONSERVATION OF NATURAL RESOURCES BY UTILISING WASTE MATERIALS EFFECTIVELY AND OPTIMISING THE USE OF EXPENSIVE STEEL AND CEMENT. FURTHER, THE ARCH DISTRIBUTESTHE POINT LOAD IN ALL DIRECTION EQUALLY THUS, IS ABLE TO WITHSTAND IMPACT LOADING AT ANY POINT.•DIAGONAL G RID OF FUNICULAR SHELL GIVES THE ILLUSION OF A LARGER SPACE.•ELIMINATE USE OF HIGH-ENERGY STEEL REINFORCEMENT USED IN THE CONVENTIONAL RCC ROOF.•ALLOWS EFFICIENT USE OF WASTE MATERIALS AND PROVIDES PERSONALITY, COLOUR AND TEXTURE.• MINIMISES REQUIREMENT OF INTERNAL PLASTERS.• PROVIDES ROOFING AT A LOWER COST.

! A DOUBLY CURVED STRUCTURE ON EDGE BEAM ENSURES OPTIMAL UTILISATION OF STEEL AND CEMENT.! CAN BE DEMOULDED EVERY 48 HOURS.! A SIMPLE YET SPLENDID ROOFING SYSTEM USING NATURAL MATERIALS AND TECHNOLOGY AS OPPOSED TO THE MONOTONOUS AND COMPLEX CONVENTIONAL SYSTEM.! FUNICULAR SHELLS CAN TAKE ANY SHAPE- SQUARE, RECTANGLE, TRAPEZIUM, TRIANGULAR OR ANY OTHER SHAPE. THE KNACK LIES IN THE CASTING OF THE MOULD.! THE UPPER HALF OF THE EDGE BEAM IS REQUIRED TO HOLD THE STIRRUPS. IT IS CAST ALONG WITH THE FUNICULAR SHELL; THEREFORE, IT CAN ALSO BE A TRIANGULAR SECTION.! THE FUNICULAR SHELL CAN CARRY VARIOUS CONDUITS, TOILET PIPES IN THE AREA ABOVE THE BRICK -BAT LAYER. THESE CAN RUN ALONG THE PERIPHERY WHERE THE MAXIMUM DEPTH IS AVAILABLE.! FUNICULAR SHELL ROOF FACILITATES THE INSTALLMENT OF FIXTURES LIKE- CEILING FANS, LIGHT FIXTURES ETC. A SKYLIGHT CAN BE INTRODUCED IN THE ROOF. THIS CAN BE ACHIEVED BY LEAVING A HOLLOW WHILECASTING, USING THE INHERENT STRENGTH OF A RING IN COMPRESSION.! THE FUNICULAR SHELL ALLOWS AMPLE FLEXIBILITY IN DESIGN

GEODESIC DOMES

•THE BASIC TRIANGLE OF AN ICOSAHEDRON IS SUBDIVIDED INTO SMALLER TRIANGLES AND EACH NODE LIFTED TO MEETTHE SURFACE OF THE SPHERE.• THE MORE THE SUB-DIVISIONS, THE SMOOTHER THE DOME. EACH SIDE OF THE SUBDIVIDED TRIANGLE RESULTS IN A CHORD FACTOR, WHICH IS MULTIPLIED BY THE RADIUS TO GIVE THE STRAIGHT LENGTH OF EACH MEMBER. •EVEN THOUGH AN ICOSAHEDRON HAS BEEN TAKEN AS THE BASIC STARTING CONFIGURATION, ANY POLYHEDRA CAN BE USED BUT THE NUMBER OF VARIATIONS IN PLATE IS LIKELY TO INCREASE DEPENDING ON THE POLYHEDRA TAKEN FOR THE BASIC GEOMETRY. •THE NUMBER OF VARIATIONS IN THE JOINT PLATES IS EVIDENT.

GEODESIC DOMES

! SIMPLE MILD STEEL PLATES ARE USED, WHICH ARE EASY TOFABRICATE CONSIDERING ONLY A HOLE AND A SLOT HAVE TOBE MADE IN IT.! SINCE THE PLATES ARE DEPRESSING THE STRUCTURAL STEELNO SUB-STRUCTURE IS REQUIRED TO ACCOMMODATEROOFING MATERIAL! THE TOP OF THE STRUCTURAL MEMBER SERVES FOR THE SEATOF THE ROOFING MATERIAL.! A SIMPLE HOLE AND SLOT IN THE PLATES PROVIDE FORVARIATIONS IN ANGLES. THE HOLE FIXES THE DISTANCE ANDTHE SLOT PROVIDES ADJUSTMENT FOR THE ANGLES.! BY CURVING THE INNER AND OUTER PLATES AND MOVING THE SLOT AND THE HOLE BY FEW MILLIMETRES CLOSERTO THE CENTRE, THE BOLTS ARE MADE TO CONVERGE TOWARDS THE CENTRE OF THE SPHERE.! MEMBERS CAN BE DOUBLED IN DEPTH IF REQUIRED.

A FRAMES

•ARE WELDED FROM INCEPTION. THESE MEMBERS ARE MORE RESILIENT THAN REINFORCED CEMENT CONCRETE AND HAVE A LARGER STRENGTH EVEN WITHOUT THE CONCRETE COMPONENT. •THIS FORM OF REINFORCEMENT CONSUMES 30% LESS STEEL. •THEY PROVIDE FOR A SIMPLE ASSEMBLY OF BEAMS WITH CONTINUITY BARS AT JUNCTIONS IN VARIOUS DIRECTIONS AND REQUIRE MINIMUM FORMWORK FOR FILLING.•THEY ARE STABLE WITHOUT CONCRETE AS CONCRETE IS REDUCED TO A FILLER MATERIAL.•THE MEMBERS CAN BE FILLED WITH CONCRETE AT ANY POINT OF TIMESUBSEQUENTLY.

SWARAN SINGH BLOCK

•TAKE A SIMPLE, MANUALLY OPERATED BLOCK MAKING MACHINE AS AVAILABLE WITH MOST OF THE BUILDING CENTRES •TAKE A STIFF PVC SHEET OR RED MUD PLASTIC SHEET CUT TO THE SIZE OF THE BASE OF THE MOULD.• COAT IT WITH USED MOBIL OIL TO PREVENT ADHESION AND FACILITATE EASY DEMOULDING FROM THE SURFACE OF THE BLOCK.•STONE PIECES OF DIFFERENT COLORS AND ARRANGE THEM IN PATTERNS AS MAY BE DESIRED FOR THE PURPOSE OF ARTICULATION OF MATERIALS.•PREPARE A 1: 3 MIX OF CEMENT AND SAND MORTAR. POUR THE MORTAR EVENLY OVER THE STONE CHIPS•THE VIBRATION HELPS INTEGRATION OF THE STONE•PIECES WITH THE CEMENT MORTAR TO FORM AN IMPERMEABLE DIAPHRAGM..•PREPARE ANOTHER MIX OF MUD WITH 2% CEMENT OR 5% LIME OR THE COMBINATION OF THE TWO. THIS MIX FORMS THE MAJOR PORTION OF THE BODY OF THE BLOCK. .

•TAKE A JUTE PIECE LITTLE SMALLER THAN THE SIZE OF THE BASE AND DIP IT IN CEMENT SLURRY. PLACE THE JUTE PIECE IN THE MOULD AND FILL THE REST OF THE MOULD WITH THE SAME MIX TO ABOUT 2/3 RD OF THE MOULD AND ADD ANOTHER LAYER OF JUTE DIPPED IN CEMENT SLURRY.•NOW FILL THE MOULD TO THE TOP. LOCK THE LID AND USE THE COMPRESSOR TO COMPRESS THE BLOCK•SURFACE OF THE WALL AND WILL REQUIRE A FLASH COAT LATER IF AT ALL, ONLY TO EVEN OUT THE SURFACE.

INTERLOCKING HOLLOW CONCRETE BLOCKS

VENE BLOCKS•THE VENE BLOCK IS ESSENTIALLY AN ADOBE BLOCK MAKING MECHANISM THAT IS SIMPLE ANDEFFICIENT. •IT COMPRISES OF A MOULD MADE OF TIMBER. THE MOULD IS USED TO MAKE THE ADOBE BLOCKS RIGHT WHERE THE WALL IS TO BE ERECTED, AND RELIES ON A SIMPLE NON-MECHANISEDPROCEDURE.•THE MOULD IS PLACED WHERE REQUIRED AND THEN EARTH MIXTURE IS POURED IN AND COMPACTED WITHIN THE MOULD. ONCE THE MOULD IS FILLED AND ALL THE EARTH WITHIN COMPACTED, THE MOULD IS LIFTED OUT AND MOVED AHEAD TO MAKE THE NEXT BLOCK. •THE SAME PROCESS IS REPEATED. THE MOULD ENSURES THAT THE BLOCKS ARE LAID PRECISELY AND GIVES IT ACLEANER FINISH THAN THE ROUGH, HAND COMPACTED ADOBE WALLS.

•BY INTEGRATING THE RAM LOCHAN TILE INTO THE VENE BLOCK MAKING PROCESS, PLACING THE TILE INTO THE MOULD BEFORE WE START COMPACTING THE EARTH, WE PROTECT THE ADOBE WALL FROMEROSION. •THE RAM LOCHAN TILE IS A FABRICATED ON SITE A SIMPLE MOULD. TO ACCOMMODATE THIS 10 MM TILE TILE, THE SIZE OF THE VENE BLOCKMOULD IS INCREASED SLIGHTLY.• BOTH THE REGULAR AND THE CORNER MOULDS ARE MODIFIED IN THIS MANNER. THE RAM LOCHAN TILE IS ALSO MODIFIEDTO ALLOW FOR TWO DOVETAIL LOCKS.•FOR THE CORNERS ONE OF THE DOVETAILS IS MADE SHORTER TO ALLOWFOR A CLEAN JOINT.THE LOWER DOVETAIL OF THE TILE ALLOWS FOR APRECISE OVERLAPPING OF THE TILES.•THE RAM LOCHAN TILE IS INSERTED INTO THE VENEBLOCK MOULD DURING CONSTRUCTION AND IS MADETO OVERLAP THE LOWER COURSE BY HALF AN INCH ,

FILLER SLAB

COST REDUCTION TECHNIQUES

1 FOUNDATION• NORMALLY THE FOUNDATION COST COMES TO ABOUT 10 TO

15% OF THE TOTAL BUILDING AND USUALLY FOUNDATION DEPTH OF 3 TO 4 FT. IS ADOPTED FOR SINGLE OR DOUBLE STOREY BUILDING AND ALSO THE CONCRETE BED OF 6″(15 CMS.) IS USED FOR THE FOUNDATION WHICH COULD BE AVOIDED.

• IT IS RECOMMENDED TO ADOPT A FOUNDATION DEPTH OF 2 FT.(0.6M) FOR NORMAL SOIL LIKE GRAVELY SOIL, RED SOILS ETC.,

• USE THE UNCOURSED RUBBLE MASONRY WITH THE BOND STONES AND GOOD PACKING.

• SIMILARLY THE FOUNDATION WIDTH IS RATIONALIZED TO 2 FT.(0.6M).

• TO AVOID CRACKS FORMATION IN FOUNDATION THE MASONRY SHALL BE THOROUGHLY PACKED WITH CEMENT MORTAR OF 1:8 BOULDERS AND BOND STONES AT REGULAR INTERVALS.

• IT IS FURTHER SUGGESTED TO ADOPT ARCH FOUNDATION IN ORDINARY SOIL FOR EFFECTING REDUCTION IN CONSTRUCTION COST UP TO 40%.

• THIS KIND OF FOUNDATION WILL HELP IN BRIDGING THE LOOSE POCKETS OF SOIL WHICH OCCURS ALONG THE FOUNDATION.

• IN THE CASE OF BLACK COTTON AND OTHER SOFT SOILS IT IS RECOMMEND TO USE UNDER REAM PILE FOUNDATION WHICH SAVES ABOUT 20 TO 25% IN COST OVER THE CONVENTIONAL METHOD OF CONSTRUCTION.

REAMED PILE FOUNDATION

ARCH FOUNDATION

2 WALLING•WALL THICKNESS OF 6 TO 9″ IS RECOMMENDED FOR ADOPTION IN THE CONSTRUCTION OF WALLS ALL-ROUND THE BUILDING AND 41/2 ” FOR INSIDE WALLS.• IT IS SUGGESTED TO USE BURNT BRICKS WHICH ARE IMMERSED IN WATER FOR 24 HOURS AND THEN SHALL BE USED FOR THE WALLS3 RAT – TRAP BOND WALL•IT IS A CAVITY WALL CONSTRUCTION WITH ADDED ADVANTAGE OF THERMAL COMFORT AND REDUCTION IN THE QUANTITY OF BRICKS REQUIRED FOR MASONRY WORK. •BY ADOPTING THIS METHOD OF BONDING OF BRICK MASONRY COMPARED TO TRADITIONAL ENGLISH OR FLEMISH BOND MASONRY, IT IS POSSIBLE TO REDUCE IN THE MATERIAL COST OF BRICKS BY 25% AND ABOUT 10TO 15% IN THE MASONRY COST. •BY ADOPTING RAT-TRAP BOND METHOD ONE CAN CREATE AESTHETICALLY PLEASING WALL SURFACE AND PLASTERING CAN BE AVOIDED.

COMPARISON

• 4 CONCRETE BLOCK WALLING• IN VIEW OF HIGH ENERGY CONSUMPTION BY BURNT BRICK IT IS

SUGGESTED TO USE CONCRETE BLOCK (BLOCK HOLLOW AND SOLID) WHICH CONSUMES ABOUT ONLY 1/3 OF THE ENERGY OF THE BURNT BRICKS IN ITS PRODUCTION.

• BY USING CONCRETE BLOCK MASONRY THE WALL THICKNESS CAN BE REDUCED FROM 20 CMS TO 15 CMS.

• CONCRETE BLOCK MASONRY SAVES MORTAR CONSUMPTION, SPEEDY CONSTRUCTION OF WALL RESULTING IN HIGHER OUTPUT OF LABOUR, PLASTERING CAN BE AVOIDED THEREBY AN OVERALL SAVING OF 10 TO 25% CAN BE ACHIEVED.

5 SOIL CEMENT BLOCK TECHNOLOGY•IT IS AN ENERGY EFFICIENT METHOD OF CONSTRUCTION WHERE SOIL MIXED WITH 5% AND ABOVE CEMENT AND PRESSED IN HAND OPERATED MACHINE AND CURED WELL AND THEN USED IN THE MASONRY. •THIS MASONRY DOESN’T REQUIRE PLASTERING ON BOTH SIDES OF THE WALL. •THE OVERALL ECONOMY THAT COULD BE ACHIEVED WITH THE SOIL CEMENT TECHNOLOGY IS ABOUT 15 TO 20%

•6 DOORS AND WINDOWS•IT IS SUGGESTED NOT TO USE WOOD FOR DOORS AND WINDOWS AND IN ITS PLACE CONCRETE OR STEEL SECTION FRAMES SHALL BE USED FOR ACHIEVING SAVING IN COST UP TO 30 TO 40%.•SIMILIARLY FOR SHUTTERS COMMERCIALLY AVAILABLE BLOCK BOARDS, FIBRE OR WOODEN PRACTICAL BOARDS ETC., SHALL BE USED FOR REDUCING THE COST BY ABOUT 25%.•BY ADOPTING BRICK JELLY WORK AND PRECAST COMPONENTS EFFECTIVE VENTILATION COULD BE PROVIDED TO THE BUILDING AND ALSO THE CONSTRUCTION COST COULD BE SAVED UP TO 50% OVER THE WINDOW COMPONENTS.•ALUMINIUM, IRON, CONCRETE FRAMES CAN BE USED

•7 LINTELS AND CHAJJAS•THE TRADITIONAL R.C.C. LINTELS WHICH ARE COSTLY CAN BE REPLACED BY BRICK ARCHES FOR SMALL SPANS AND SAVE CONSTRUCTION COST UP TO 30 TO 40% OVER THE TRADITIONAL METHOD OF CONSTRUCTION.• BY ADOPTING ARCHES OF DIFFERENT SHAPES A GOOD ARCHITECTURAL PLEASING APPEARANCE CAN BE GIVEN TO THE EXTERNAL WALL SURFACES OF THE BRICK MASONRY.

LAURIE BAKER

LAURIE BAKER, AN ARCHITECT FROM BIRMINGHAM, NOW SETTLED IN THIRUVANANTHAPURAM, HAS EFFECTIVELY COMBINED TRADITIONAL TECHNIQUES WITH INDIGENOUS INNOVATIONS AND HAS MANAGED TO BRING DOWN THE COST OF CONSTRUCTION BY HALF. HIS TECHNIQUES NOT ONLY USE CHEAPER MATERIALS BUT ALSO ELIMINATE REDUNDANT DETAILS FROM THE DESIGN.

CONCRETE IS RARELY USED. MANGALORE TILES ARE USED FOR THE ROOF WHICH MAKES IT LIGHT AND INEXPENSIVE.

• HIS APPROACH AND SIMPLE PRINCIPLES TO LOW COST HOUSING ARE GANDHIAN, WHICH CAN BE ADOPTED BY EVERY BUILDER. THE FOLLOWING ARE THE MAINSTAY OF DESIGN AND CONSTRUCTION OF HIS HOUSES.

• PLANNING OF SPACE– LESSER WALLS, MULTIPLE USES OF SPACE, SHORT SPANS OF ROOF, AGGLOMERATION OF BUILDING SERVICES, FLEXIBILITY IN GROWTH.

• LOCAL BUILDING MATERIAL– BRICKS, TILES, LIME, SURKHI, TIMBER, THATCH, STONE, PALM, MUD.

• BRICKS AND JALIS – PLAY OF LIGHT AND SHADE, UNIDIRECTIONAL VISION.

• UNPLASTERED WALLS.• LINTELS AND ARCHES.• ATTENTION TO DETAILS.

• BAKER’S WORKS INCLUDE, PRIVATE RESIDENCES, SOME INSTITUTIONAL BUILDINGS, LIKE ‘CENTER FOR DEVELOPMENT STUDIES’, KERALA. HE IS VERY ACTIVE IN THE WORKS OF ALL THE BUILDING CENTERS WORKING IN KERALA AS WELL AS IN THE OTHER PARTS OF COUNTRY. RATHER IT WAS HIS INITIAL EFFORT TO PROMOTE THE LOW COST HOUSING IN INDIA, WHERE HOUSING IS A BIG PROBLEM.

• HIS TECHNIQUES NOT ONLY USE CHEAPER MATERIALS BUT ALSO ELIMINATE UNNECESSARY DETAILS FROM THE DESIGN. CONCRETE IS SPARINGLY USED. MANGALORE TILES ARE USED FOR THE ROOF WHICH MAKES IT LIGHT AND INEXPENSIVE.

• HIS PROJECTS FOR LOW COST BUILDINGS INCLUDE

1. CENTER FOR DEVELOPMENT STUDIES – TRIVANDRUM

2. 'THE HAMLET', LAURIE BAKER'S HOME THIRUVANANTHAPURAM,

CENTER FOR DEVELOPMENT STUDIES - TRIVANDRUM -1975

• LESLIE BAKER’S ‘MASTERPIECE,’ THE CENTRE FOR DEVELOPMENT STUDIES IN KERALA, IS A 10 ACRE CAMPUS AT A COST OF RS15 LAKHS, DEMONSTRATED THE EFFECTIVENESS OF HIS PLAN.

• THE INSTITUTE INCLUDES A RESEARCH INSTITUTE. A GRADUATE SCHOOL

DEDICATED TO UTILIZING THE STUDY OF ECONOMICS TO HELP THE POOR.

MAIN FEATURES OF THIS BUILDING: • HE DESIGNED THE BUILDINGS AT

THE CENTRE TO PRACTICALLY COOL THEM.

• HE RENDERS JALIS, A PERFORATED WOODEN SCREEN FOUND IN TRADITIONAL INDIAN ARCHITECTURE, IN BRICK;

• THE OPEN GRILLWORK ALLOWS COOL BREEZES TO WAFT INTO THE INTERIOR WHILE FILTERING HARSH, DIRECT SUNLIGHT.

• SOME BUILDINGS INCLUDE A SERIES OF SMALL COURTYARDS CONTAINING SHALLOW POOLS IN THE CENTER, WHOSE EVAPORATION HELPS COOL THE AIR.

• PAYING CLOSE ATTENTION TO THE EXISTING SITE AS HE BEGAN TO DESIGN THE PROJECT, BAKER LEFT AS MANY COCONUT PALM TREES IN PLACE AS POSSIBLE TO CAST COOLING SHADE ONTO THE CAMPUS.

• THE COMPUTER CENTRE AT THE CENTRE FOR DEVELOPMENT STUDIES, THIRUVANANTHAPURAM. HERE BAKER EVOLVED AN INNOVATIVE SYSTEM OF CURVED DOUBLE WALLS TO SAVE ON COST AND TO CONSERVE THE ENERGY .

• IN EVALUATING THE CAMPUS FOR THE CENTRE, BAKER PLANNED ROADS ALONG THE LOWER, WHILE FOOTPATHS WERE ROUTED ALONG NATURALLY OCCURRING ELEVATED AREAS; FOLLOWING THE NATURAL TOPOGRAPHY HELPS TO LIMIT EROSION AND DESPOILMENT OF THE ENVIRONMENT.

• BRICKWALLS WERE LEFT UNPLASTERED AND BRICK CORBELLING WAS USED RATHER THAN MORE EXPENSIVE CONCRETE LINTELS.

• WITH HIS MASTERY OVER HIS MEDIUM, BAKER CREATES A VARIETY OF TEXTURES AND PATTERNS BY SIMPLE MANIPULATION OF THE WAY IN WHICH BRICKS ARE PLACED IN THE WALL.

• THE ARCHITECTURE OF THIS ACADEMIC COMPLEX WAS CONCEIVED AS A DEMONSTRATION OF ECONOMICALLY RESPONSIBLE BUILDING PRACTICES.

BAKER’S HOUSE “THE HAMLET”

• BAKER’S OWN RESIDENCE IS CALLED ‘THE HAMLET’. IT HAS BEEN BUILT IN THIRUVANANTHAPURAM, BUILT ON A STEEPLY SLOPING AND ROCKY HILLSIDE THAT HARDLY HAD ANY VEGETATION WHEN BAKER STARTED CONSTRUCTING.

• BAKER HAS TRULY ADOPTED HIS MOTTO TO “MAKE LOW-COSTERY A HABIT AND A WAY OF LIFE” BY REUSING EVERYTHING, FROM BRICK TO GLASS BOTTLES, AS BUILDING MATERIALS.

• KEY FEATURES OF HIS HOUSE ARE:ALL THE WALLS ARE MADE OF MUD BRICKS.TIMBER SALVAGED FROM AN OLD BOAT JETTY.

• ONE OF THE OTHER SIGNATURE ELEMENTS OF HIS DESIGN INCLUDES THE USE OF CIRCULAR WALLS, WHICH USE FAR LESS BRICK THAN RECTANGULAR WALLS.

• IN ADDITION, WHEN HE DOES USE CONCRETE FOR A ROOF, HE EMBEDS CHIPPED OR BROKEN TERRA COTTA ROOFING TILES INTO THE MIXTURE.

• THESE TILES, WHICH NORMALLY WOULD BE THROWN AWAY, CONTRIBUTE TO THE STRENGTH OF THE ROOF, ALLOW LESS OF THE EXPENSIVE CONCRETE TO BE USED, AND REDUCE THE STRUCTURAL LOAD OF THE BUILDING.

• HE USED BROKEN TILES FOR THE OUTER PAVED AREA OF HIS GARDEN.

• HE MADE AN EXTENSIVE USE OF TIMBER IN HIS HOUSE, LIKE IN THE LIVING ROOM OF HOUSE, THE DETAILING IN WOOD AND MUD BRICKS ARE WONDERFUL.

• THE LIVING ROOM, AN INTEGRATION OF NEW BUILDING AND SALVAGED TIMBER FROM TRADITIONAL BUILDINGS THAT WERE BEING DEMOLISHED.

• BAKER'S INNOVATIVE USE OF DISCARDED BOTTLES, INSET IN THE WALLS GIVING A VERY GOOD EFFECT OF LIGHT AND CREATING AN ILLUSION OF STAINED GLASS.