Imag­ine an af­ford­able code

Mass hous­ing is the or­der of the day. If planned well, they have the po­ten­tial to drive the econ­omy to­wards a low-carbon fu­ture

Down to Earth - - LIFESTYLE -

GREEN­ING OF the built environment is not just about in­di­vid­ual houses or of­fice units. In­dia wit­nesses mas­sive mass con­struc­tion of homes, es­pe­cially in new ur­ban ex­ten­sions and town­ships. While some rudi­men­tary rules ex­ist in some cities for rain­wa­ter con­ser­va­tion and waste man­age­ment in build­ings, the en­ergy con­ser­va­tion build­ing code of the Bu­reau of En­ergy Ef­fi­ciency does not ap­ply to hous­ing yet. Early ac­tion in this sec­tor is im­por­tant to avert mas­sive re­source guz­zling.

Even as rules are tak­ing shape for re­source sav­ings in the hous­ing sec­tor, the real es­tate in­dus­try can vol­un­tar­ily take proac­tive steps to adopt green mea­sures. Some de­vel­op­ers are al­ready tak­ing the lead in this di­rec­tion.

Chandrasekhar Har­i­ha­ran, a pi­o­neer in ze­roen­ergy homes in In­dia, is one such de­vel­oper. His or­gan­i­sa­tion, Bio­di­ver­sity Con­ser­va­tion In­dia Ltd ( bcil), has built over 2 mil­lion square feet (over 185,000 sq m) of zero-en­ergy homes across Bengaluru, Chennai and My­suru. Har­i­ha­ran says it is pos­si­ble for de­vel­op­ers to in­no­vate and re­duce fresh­wa­ter con­sump­tion and en­ergy use from the grid by 30 per cent. About 70 per cent of the en­ergy can be saved through smart de­mand side man­age­ment, or be sourced from lo­cal sup­ply side so­lu­tions. All these can be achieved through ef­fi­cient use of space, ad­vanced con­struc­tion meth­ods, and sus­tain­able build­ing ma­te­ri­als.

bcil has used cav­ity or hol­low blocks for walls of ev­ery zero-en­ergy home. The cav­ity of­fers ther­mal in­su­la­tion, and has all the elec­tri­cal and plumb­ing points in­serted from within, with­out the messy chas­ing and chis­elling of walls that reg­u­lar homes suf­fer af­ter the plas­ter­ing is done. Be­sides, com­paction strength of these blocks is 7.2 Newton, whereas that of the solid con­crete block is 4.5 Newton. This means, hol­low blocks can with­stand more load com­pared to other blocks. So, hol­low blocks are cost-ef­fec­tive, even though they cost 20 per cent more than the con­crete blocks. Since there is no break­age, the wastage is next to noth­ing.

The zero-en­ergy homes have bam­boo floor­ing. It might be ex­pen­sive, but is eco-friendly be­cause bam­boo is a rapidly re­new­able ma­te­rial. The floors last long and the en­ergy con­sumed in their mak­ing, called em­bod­ied en­ergy, is low. But the down­side is they are im­ported from China, and trans­porta­tion cost off­sets the low em­bod­ied en­ergy cost.

The zero-en­ergy homes have also adopted cool roof tech­niques in which turfed roofs make for nat­u­ral, cool spa­ces, with the grass being of­fered mois­ture, not wa­ter, with a sprin­kler sys­tem that is low on cost and en­ergy.

To keep the op­er­a­tional en­ergy low, the fo­cus

has been on the use of en­ergy-ef­fi­cient ap­pli­ances. These homes have fans that run at 28 Watts against the 75 Watt reg­u­lar ceil­ing fan. It serves as a chan­de­lier as well. They use 0.8 tonne ACs that work on 5-amp plug points. These ACs cool the home like any other AC, and re­duce the en­ergy cost by 70 per cent as com­pared to the reg­u­lar 1.2 tonne AC.

In mass hous­ing, the use of open com­mu­nity spa­ces mat­ter a lot. The space should be used to cre­ate small wa­ter­bod­ies, which lower the mi­cro­cli­mate tem­per­a­ture while adding to the aes­thet­ics. Very small low-en­ergy pumps that are so­lar-pow­ered should be in­stalled in these wa­ter bod­ies to en­sure that the wa­ter is aer­ated reg­u­larly, so that the pool does not be­come a cesspool for in­sects. In the cam­pus of bcil’s zero-en­ergy homes, roads have been built out of de­bris.

Clearly, there is an op­por­tu­nity to in­flu­ence the new and enor­mous built spa­ces. How­ever, says Har­i­ha­ran, a ma­jor chal­lenge is to con­vince builders about the ad­van­tages of go­ing green. There are also not enough experts to guide builders. “usa has a stag­ger­ing 78,000 ac­cred­ited pro­fes­sion­als for 10.6 bil­lion sq ft (985 mil­lion sq m). In In­dia there are no more than 2,000 for 3.5 bil­lion sq ft (325 mil­lion sq m) un­der green build­ings.”

Mass con­struc­tion needs guid­ing prin­ci­ples not only for build­ing struc­tures but also for sus­tain­able ur­ban de­sign. This needs mixed use neigh­bour­hoods and build­ings, small block sizes de­signed for high den­sity and af­ford­able hous­ing, use of open spa­ces and dis­in­cen­tives for gated com­mu­ni­ties. But a dan­ger­ous trend is set­ting in where higher floor area ra­tio ( far) is being pro­moted with­out defin­ing den­sity re­quire­ments, ur­ban de­sign norms and green fea­tures for mass hous­ing.

A dan­ger­ous trend is set­ting in where high floor area ra­tio is being pushed with­out first defin­ing den­sity re­quire­ments, mixed in­come use, ur­ban de­sign norms and green fea­tures for mass hous­ing

How to move for­ward

A rapid re­view of emerg­ing good prac­tices in the coun­try shows that pro­gres­sive ar­chi­tects are al­ready in­no­vat­ing and go­ing much be­yond the lim­ited green build­ing poli­cies and reg­u­la­tions to achieve sus­tain­abil­ity and re­source ef­fi­ciency. Ashok B Lall, a lead­ing ar­chi­tect in Delhi, says pro­gres­sive ar­chi­tec­ture re­tains the cul­tural imag­i­na­tion, and brings in a lot of in­no­va­tive meth­ods and tech­nolo­gies to meet the ob­jec­tive of eq­uity. This tra­di­tional knowl­edge must be ex­tracted to add a layer of sci­en­tific un­der­stand­ing to strengthen it.

There are chal­lenges too. San­jay Prakash, ar­chi­tect with Delhi-based Stu­dio for Habi­tat Fu­tures, says one has to relook at the whole sys­tem to make a low-emis­sion build­ing. One has to in­cor­po­rate mea­sures that al­low nat­u­ral ven­ti­la­tion, day­light and in­su­la­tion, con­sider the shade, colour and ori­en­ta­tion of the build­ing, as well as veg­e­ta­tion and life­style adap­ta­tions like tol­er­at­ing a higher tem­per­a­ture than what the air-condition in­dus­try pro­vides. But life­style adap­ta­tions are frowned upon by the global cos­mopoli­tan com­mu­nity and the in­dus­try, and there­fore, not pop­u­lar for main­stream ap­pli­ca­tion. But such build­ings are sus­tain­able and cost less. “Ob­vi­ously, in­ter­nal white paint for day­light is cheaper than coloured in­te­ri­ors, suit­able ori­en­ta­tion costs noth­ing, and re­duc­ing glass re­duces cap­i­tal cost,” adds Prakash.

It is clear that the ac­cu­mu­lated ar­chi­tec­tural wis­dom and imag­i­na­tion has to lead the green build­ing poli­cies and prac­tices, so that build­ings are sus­tain­able and help im­prove the over­all qual­ity of life. Emerg­ing good prac­tices show how ar­chi­tec­tural and ma­te­rial in­no­va­tion and ju­di­cious use of mod­ern tech­nol­ogy can help in­form the builder and con­sumer to up­scale so­lu­tions.

This needs to be backed by poli­cies for re­source ef­fi­ciency in build­ings to set rig­or­ous and trans­par­ent tar­gets for re­source sav­ings, and a strong com­pli­ance strat­egy to en­sure that build­ings con­tinue to re­main ef­fi­cient while in use to en­sure real re­source sav­ings.

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