. ▁ ▁Performance ▁based ▁H ERS : In ▁this ▁H ERS , ▁the ▁energy ▁efficiency ▁of ▁building ▁is ▁checked ▁by ▁comparing ▁the ▁actual ▁energy ▁consumption ▁data ▁against ▁the ▁set ▁standards . ▁ ▁Need ▁for ▁H ERS ▁In cre ase ▁in ▁population , ▁Econom ic ▁issues ▁are ▁the ▁some ▁factors ▁which ▁have ▁es cal ated ▁the ▁energy ▁demand ▁across ▁the ▁world . ▁In ▁developed ▁countries , ▁the ▁growth ▁rate ▁of ▁energy ▁consumption ▁rate ▁is ▁ 1 . 1 % / year ▁while ▁in ▁developing ▁countries ▁the ▁energy ▁consumption ▁growth ▁rate ▁approximately ▁ 3 ▁time ▁to ▁that ▁of ▁developed ▁countries . ▁Bes ide ▁this ▁high ▁growth ▁in ▁energy ▁consumption ▁it ▁also ▁causes ▁to ▁increase ▁the ▁production ▁of ▁green ▁house ▁g ases ▁to ▁the ▁atmosphere . ▁The ▁increase ▁in ▁demand ▁of ▁energy , ▁limited ▁resource ▁of ▁convention ▁energy ▁sources , ▁hi ke ▁in ▁conventional ▁fuel ▁prices , ▁global ▁war ming ▁are ▁some ▁important ▁factors ▁which ▁Imp et us ▁us ▁to ▁adopt ▁energy ▁saving ▁techniques ▁and ▁alternative ▁sources ▁of ▁energy . ▁Building ▁sector ▁cons umes ▁one ▁third ▁of ▁world ' s ▁resources . ▁Building ▁currently ▁shares ▁approximately ▁ 4 0 % ▁of ▁energy ▁in ▁most ▁of ▁the ▁countries ▁and ▁are ▁considered ▁among ▁the ▁largest ▁end - use ▁sector . ▁As ▁per ▁International ▁energy ▁ag ency ▁( IE A ) ▁world ▁energy ▁consumption ▁and ▁green ▁house ▁g ases ▁level ▁is ▁going ▁to ▁increase ▁rapidly ▁every ▁year . ▁IE A ▁recognize ▁the ▁building ▁sector ▁as ▁one ▁of ▁the ▁most ▁cost ▁effective ▁sector ▁where ▁energy ▁consumption ▁can ▁be ▁reduced ▁.