Build it bet­ter

To shrink a build­ing’s car­bon foot­print, start by mak­ing walls and roofs from green ma­te­ri­als.

The Star Malaysia - Star2 - - FRONT PAGE - By TAN CHENG LI star2­green@thes­

WANT to green your home or build­ing? For­get about the eco-blings, those stuff like pho­to­voltaic cells, wind tur­bines, build­ing au­toma­tion, smart light­ing sys­tems, and what not. Sure, shiny so­lar panels on the rooftop will im­press neigh­bours and shout “This is a green build­ing” but it is point­less gen­er­at­ing green en­ergy or us­ing au­to­mated con­trols of lights, blinds and ap­pli­ances if the struc­ture it­self is an en­ergy-guz­zler due to poor de­sign.

Be­fore spend­ing huge sums on these green giz­mos, make sure the build­ing does not re­quire much elec­tric­ity in the first place – what is known as “pas­sive build­ings.” In our trop­i­cal cli­mate, these would be struc­tures that are shaded and in­su­lated from the heat as air-con­di­tion­ing is a ma­jor rea­son be­hind soar­ing elec­tric­ity bills.

Green build­ing con­sul­tant Gregers Reimann shares that in one build­ing in Jakarta, In­done­sia, en­ergy sav­ings of 40% was achieved by mak­ing its fa­cade air­tight. Be­fore retrofitting works, leaky doors, win­dows and par­ti­tion gaps had led to over-use of air-con­di­tion­ing.

“Most peo­ple, when they think green, they think of so­lar panels. That should be the last thing to do,” says the en­ergy en­gi­neer from IEN Con­sul­tants.

Ar­chi­tect and sus­tain­able build­ing ad­vo­cate Dr Tan Loke Mun shares the same view. Tan says the pre­ferred way to green a struc­ture is to first look at “pas­sive cool­ing” by em­ploy­ing mea­sures such as shad­ing, build­ing ori­en­ta­tion and erect­ing walls that pro­vide ther­mal in­su­la­tion.

“In­stalling so­lar panels is an additional cost. For walls, you have to build them any­way and you’re al­ready in­cur­ring cost, so you might as well use the green­est ma­te­rial pos­si­ble. It’s the low-hang­ing fruit. Walls keep the heat out right from the start and pro­vide pas­sive cool­ing for 24 hours. So you won’t need more elec­tric­ity for cool­ing. It’s a no-brainer. Other­wise, you’ll be spend­ing money to cool down the house,” says Tan, who had been in­volved in de­vel­op­ing the Green Build­ing In­dex (GBI), Malaysia’s cer­ti­fi­ca­tion scheme for build­ings that have a lighter en­vi­ron­men­tal im­print.

High car­bon load

The con­struc­tion in­dus­try is ter­ri­bly un­kind to the planet; it de­pletes raw ma­te­ri­als, guz­zles en­ergy, and leaves be­hind waste and green­house gases.

“It is known that build­ings con­sume up to a third of the world’s re­sources, emit 40% of global green­house gases, use up 12% of its fresh­wa­ter, and gen­er­ate 40% of its solid waste. Thus em­brac­ing sus­tain­able con­struc­tion is not only the re­spon­si­ble course of ac­tion, it is the only ra­tio­nal course of ac­tion we must pur­sue,” says Thiruku­maran Jal­len­dran, a board mem­ber of the Malaysia Green Build­ing Con­fed­er­a­tion, an in­dus­try group that pro­motes eco-friendly con­struc­tion tech­nol­ogy and prac­tices.

Though more car­bon is emit­ted dur­ing the life­time of a build­ing, the car­bon foot­print from the con­struc­tion it­self needs fix­ing, too. This “em­bod­ied CO2” – the CO2 that is re­leased in the man­u­fac­ture of con­struc­tion ma­te­ri­als and dur­ing con­struc­tion – has to be min­imised right from the start when de­sign­ing the build­ing and dur­ing con­struc­tion (such as by choos­ing green ma­te­ri­als) for once a struc­ture is up, the op­por­tu­nity for the sav­ing is lost.

While us­ing green con­struc­tion ma­te­ri­als and in­stalling en­ergy-ef­fi­cient equip­ment and so­lar cells are both crit­i­cal for mak­ing green build­ings, the former should be pri­or­ity, as­serts Matthias Gel­ber whose com­pany makes eco-prod­ucts.

“Low-car­bon foot­print ma­te­ri­als, pas­sive cool­ing and po­si­tion­ing of the build­ing are low or zero-cost op­tions and rep­re­sent an im­me­di­ate CO2 emis­sion sav­ing. The oth­ers are for the long-term.”

Tan points out sev­eral aspects of green ma­te­ri­als: “They must be green in their pro­duc­tion such as have re­cy­cled con­tent or are made from waste ma­te­ri­als, use min­i­mal nat­u­ral re­sources and en­ergy, and gen­er­ate lit­tle waste. The dis­tance be­tween the pro­duc­tion and con­struc­tion site should also be con­sid­ered to limit the car­bon foot­print from trans­porta­tion. In terms of per­for­mance, they must have good in­su­la­tion and acous­tic val­ues to cre­ate bet­ter in­door environment.”

Build­ing with less

En­vi­ron­men­tally prefer­able build­ing ma­te­ri­als are those that are fab­ri­cated with less en­ergy and have re­cy­cled con­tent or are made from re­new­able re­sources while at the same time func­tion as well as ex­ist­ing ma­te­ri­als.

Con­struc­tion ma­te­ri­als con­sist­ing of re­cy­cled con­tent in­clude dry­wall (uses re­cy­cled pa­per and postin­dus­trial gyp­sum), plas­tic lum­ber (uses plas­tic waste), clay roof tiles (uses fac­tory re­jects) and glass tiles (uses waste glass). Me­tals such as steel and alu­minium also have high re­cy­cled con­tent due to ex­pen­sive vir­gin ma­te­ri­als.

In some green types of build­ing blocks, wood fi­bres and waste ma­te­ri­als such as fly ash (from coal plants) and slag (waste from steel mills) are used to re­duce the need for con­crete. (See story on P4)

When it comes to ma­te­rial-se­lec­tion, Gel­ber says the con­sid­er­a­tions in­clude prod­ucts that have low CO2 and in­su­late at the same time, are free of formalde­hyde and volatile or­ganic com­pounds, and of­fer value for money. “Re­cy­cled con­tent is good but what is the point of that if there is no im­prove­ment in CO2 re­duc­tion?” He adds that mea­sure­ments on the car­bon pro­file of con­struc­tion ma­te­ri­als should be sim­pli­fied and stan­dard­ised so that peo­ple can bet­ter dis­tin­guish be­tween the green and not-so­green prod­ucts.

An­other con­sid­er­a­tion to green a build­ing, adds Reimann, is to not over-de­sign. “A lot of build­ings are over-de­signed, for in­stance, with many big beams, to be on the safe side. If you have good struc­tural en­gi­neer­ing, you can trim the de­sign and use 40% less steel and ce­ment. An­other thing is to use high-strength con­crete which can carry two to three times the weight of con­ven­tional con­crete. This will also trim down ma­te­rial use.”

Yet an­other green op­tion for the con­struc­tion sec­tor is the sal­vage and reuse of de­mo­li­tion de­bris but that is un­com­mon here. Re­cy­cling con­struc­tion waste re­duces green­house gas emis­sions by min­imis­ing the need to ex­tract and process raw ma­te­ri­als, and the en­vi­ron­men­tal im­pact of waste dis­posal. In Sin­ga­pore, used con­crete is crushed and reused. In Ger­many, con­struc­tion waste is banned from the land­fill and has to be reused. In Malaysia, de­mo­li­tion waste is mostly il­le­gally dumped.

One green build­ing ma­te­rial is a tra­di­tional one: good old clay bricks. In re­cent years, these have

lost out to the cheaper ce­ment bricks. Clay bricks have good ther­mal in­su­la­tion and so, keep homes cool. Houses these days, how­ever, are mostly con­structed with ce­ment bricks which trap heat and eas­ily dis­penses it, thus warm­ing up home in­te­ri­ors. This is why when you en­ter an old house built of bricks, it is cooler com­pared to a typ­i­cal ter­race house in any one the hous­ing schemes that make up our sub­urbs.

Tan says the in­su­la­tion prop­erty of clay bricks im­proves by build­ing cav­ity walls (dou­ble brick walls with a cav­ity in be­tween). “Brick walls are main­te­nance-free and min­imise ma­te­rial us­age as you do not need to plas­ter and paint them,” adds the ar­chi­tect, whose GBI-plat­inum-rated home fea­tures a few raw brick walls. Clay bricks can nudge up their green quo­tient if the pro­duc­tion process is made greener, such as by us­ing cleaner fuel for fir­ing and anti-air-pol­lu­tion equip­ment, and re­cy­cled con­tent.

Choices of green build­ing ma­te­ri­als are cer­tainly more varied now but many builders are still un­fa­mil­iar with them. It is mostly ar­chi­tects and de­vel­op­ers eye­ing GBI rat­ing for their projects, who seek such prod­ucts. Most hous­ing schemes and high-rises still rely on cheaper ma­te­ri­als which do not pre­vent heat build-up in in­te­ri­ors.

Tan says that in Europe, such ma­te­ri­als are used as the law re­quires it. “Here, be­cause there are no laws, not many de­vel­op­ers use such ma­te­ri­als although some have been in the mar­ket for 15 to 20 years. But peo­ple are get­ting more aware of the need to use such ma­te­ri­als. They are a bit more costly but the price dif­fer­ence is catch­ing up, and the ben­e­fits are there.”

The use of green ma­te­ri­als is an im­por­tant cri­te­ria to be cer­ti­fied un­der GBI, ac­cord­ing to Malaysia Green Build­ing Con­fed­er­a­tion pres­i­dent Von Kok Leong. “It re­wards those who use ma­te­ri­als which have re­cy­cled con­tent, are reuse­ble and re­cy­clable, and sourced from within the re­gion. The higher the re­cy­cled con­tent, the more points Con­crete is the main ma­te­rial for con­struc­tion but its use in­flates the car­bon foot­print of build­ings as pro­duc­tion of its cru­cial in­gre­di­ent, ce­ment, gives out 5% of global man-made car­bon diox­ide. are given. We also en­cour­age the use of Malaysian tim­ber that has been cer­ti­fied as sus­tain­ably pro­duced.”

Von says cur­rent build­ing by­laws and codes need to be up­graded to meet higher stan­dards on build- ing per­for­mance, so this in­di­rectly re­quires the use of greener ma­te­ri­als.

“We have to en­cour­age de­sign­ers to in­tro­duce the new, green ma­te­ri­als, de­vel­op­ers to ac­cept them, con­trac­tors to use them, and pur­chas- ers to ask for them.”

The Euro­pean Par­lia­ment last year an­nounced new en­ergy stan­dards that will re­quire all new build­ings con­structed in Europe af­ter 2020 to be nearly car­bon-neu­tral. This means build­ings must have zero-car­bon emis­sions – they must re­move as much CO2 from the at­mos­phere as they put in.

Reimann reck­ons Malaysia, too, needs to move in such a di­rec­tion if it wants to sti­fle growth of its car­bon foot­print. “The world can­not go green with­out trans­form­ing the way it builds. In the quest to re­duce green­house gas emis­sions, the build­ing sec­tor has been iden­ti­fied as the sec­tor with the big­gest and cheap­est po­ten­tial for do­ing so.”

And con­sumers buy­ing new homes, too, should make it a point to un­der­stand how the choice of bricks, build­ing blocks and con­crete can af­fect their com­fort and ul­ti­mately, the world’s cli­mate.

Re­source de­ple­tion: The con­struc­tion in­dus­try drains the world of its raw ma­te­ri­als, guz­zles en­ergy, and leaves be­hind waste and green­house gases. – Shahrul Fazry Is­mail/The Star

Huge car­bon foot­print: build­ings use a third of the world’s re­sources and emit 40% of global green­house gases.

brick walls, when left raw with­out any plas­ter­ing or paint­ing, save re­sources and con­se­quently, help shrink a build­ing’s car­bon foot­print.

The con­struc­tion in­dus­try al­ready uses steel and alu­minium with re­cy­cled con­tent due to ex­pen­sive vir­gin ma­te­ri­als.

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