Green Roofs Take Root In U.S. Building Design
SU S IA INAE ]i. TY
GreenRoofsTakeRootIn U.S.Building Design Whatwasonceconsidered a lringeideais rapidly gaining mainstream acceptance. ByJohnLoomis reeDrooh aregainingpopldadty A gren roof provides. in U.S. commer.i.l redl estate development.Adlan.es in €.h' > Redue.d mergt costs, nology and imprcved paybackperiods A conventionalroof will are e{pectedto drive evengreateradop- heatup to s much as 180 tion. Wlen integrated into the early degr$ Fahrelheit, while a dcsignstages,thry providesustainability greenrcof may oily heatup and solid returns on investment. to 80 degrees.Thus, tryAC Theuseofsoil and plantedftaterial to s)stemscan be downsized covercommercialdnd residentialbuildand operatingcostsreduced ingsis not a new concept,bui the intcrest bI asmuch as2sEo,reports in sutaiDable developnent has tueled swiDerton Buildes. which nrore innomtion dd inpletrentation. constructed capt head The largestgred roof on the last Coast, quartes and its 69,000sq. h. g.eenrcof in Culpeppe! Va., outJide Wdhington in SanBruno, Calif in 1997D.C., was ftently completedatop the > Pcdueedheat istahd elfect: h NN National Audio Visual Consewation YorkCity,the U.S.Departnent of Ener$' Centerof The Library of Congre$. estimatesthat reflectiveroofsurfacesand In Manhattan, RockefellerCenter is urb.n re vegetaiion codd lower suninstalling an 18,000sq. ft. greenrcof to mertime tempenfures by 3.6 degrees be completedthis yeai ln SanFranciso. Fahienheit. Eacb d€grce car truslate Hinej winning prcposalfor a miEd Ne to miUionsof dollan in increased air ompld of oiice twers 1,000feet high ondiiioning demand. at the TransbaytermiDal nas aided by > Lo"set nof li.fe a'td lowet tons" inclusion of a hugefire-acregreenpark ,enr corfs Gr€enrcoft protd buildjngs 70 taei abovethe nrain bus platform. fton ultraviolct-raydamageand relieve lord, neanwhne,has beena corpo lhe problen of fluciuting tenperatures rute real estateinnovator Its one acre that can dmage roofing. ReHrche6 g.een nrof atop the ormal.€r's Prehicr liom the UniE6ity of Californiaat Davis Auto c.ou! he.dquarteB in lrvine, .eportedthat geen rcofscan"doublethe Calit in 2001wasthe first lord build- life of a roof ftom 15yea6 to 30 yexsl' ing to rceive LEEDcertificationand the > stotuat r .aptutu ad pollnnot fi6t lEED-certfied proje.t in Orange flndnof: Gteen roofs act as a fiLter CouDqrThe 10.aade "living roof" on for nany airborne pollutarts that fall Fordk Dearborn,Mi.h. buck plant is rhe with the rain. A greenroof surfaceof 3 to s inchesof soil or Browing nediuh absorbs7s9oof rainf.lls that areone'half Behind thecurve inch or less.This "sponge"etrecteduces While a 2005 2006 survel by creen stormwaterrunolt and helpsrelie'e tle Roofs for Heahhy Cities estimatedthe pre$ure on urbd storm-dfrin q tcns. amount of U.S.greenroofsgrN by 25Eo > Inprcwd ab qualitf; Crcen rcors ftom the yedrbefore, represeDtingmore filter air by absrbing and ()nrelting than 3 million sq. ft., the U.S.is still cdrbon dioxide and producing or:l€en. playingcatch-upto other nations.Tolqo Researchindicatesthat a I squr meter now requires200,6of roof surfacesto bc plot of g€.ss€D renrove0.2kilogrms of green.ln CennaDy,7Eoof roof spaceis airbone particulatesftoD the air U.S.citiesarecreatinggrerioof inentives, led 104
NREI May2008
by hunicjpalities such as chicaso, New Yorlq Cambnd€e,Mass.,and Portland, Orc. Chicagoprovids a 50Eomatching giant for adding gren roofs to sisting private-sctor buildingsdowDtown.
Assessing thecosts G.eer roofs carry higher upftont costs, but rcsearcheBindicat€ they are com petiti\e on a life cyd€ basisbecauk of .edued maintenmce and repla.em€nt costs.The Cjq. ol Portland estimatesa ns grreen roof costs$l to $6 moreper sq.ft. than. standardrooi Although energyeffrciencywill offset olerational .osts. developes typically have not ben ablc to incoporite tbe highercostsinto the prcject'spro forna. Greenrool ownm canbredkevenon upfront cosrsin five to l0 vearsbasedon energysavingsdd naintenance.A study bt' the Unilersity of Michiganconcluded that the averagepatbackpcriod for more extenslvegteenroofs wasabout 20 yea.s. In otber'Nords,gren roofs not only pencil.theycan payotr iD long-tem cost savingsand enviroDmentalbenefits. I
GreenRoofsTakeRootIn U.S.Building Design Whatwasonceconsidered a lringeideais rapidly gaining mainstream acceptance. ByJohnLoomis reeDrooh aregainingpopldadty A gren roof provides. in U.S. commer.i.l redl estate development.Adlan.es in €.h' > Redue.d mergt costs, nology and imprcved paybackperiods A conventionalroof will are e{pectedto drive evengreateradop- heatup to s much as 180 tion. Wlen integrated into the early degr$ Fahrelheit, while a dcsignstages,thry providesustainability greenrcof may oily heatup and solid returns on investment. to 80 degrees.Thus, tryAC Theuseofsoil and plantedftaterial to s)stemscan be downsized covercommercialdnd residentialbuildand operatingcostsreduced ingsis not a new concept,bui the intcrest bI asmuch as2sEo,reports in sutaiDable developnent has tueled swiDerton Buildes. which nrore innomtion dd inpletrentation. constructed capt head The largestgred roof on the last Coast, quartes and its 69,000sq. h. g.eenrcof in Culpeppe! Va., outJide Wdhington in SanBruno, Calif in 1997D.C., was ftently completedatop the > Pcdueedheat istahd elfect: h NN National Audio Visual Consewation YorkCity,the U.S.Departnent of Ener$' Centerof The Library of Congre$. estimatesthat reflectiveroofsurfacesand In Manhattan, RockefellerCenter is urb.n re vegetaiion codd lower suninstalling an 18,000sq. ft. greenrcof to mertime tempenfures by 3.6 degrees be completedthis yeai ln SanFranciso. Fahienheit. Eacb d€grce car truslate Hinej winning prcposalfor a miEd Ne to miUionsof dollan in increased air ompld of oiice twers 1,000feet high ondiiioning demand. at the TransbaytermiDal nas aided by > Lo"set nof li.fe a'td lowet tons" inclusion of a hugefire-acregreenpark ,enr corfs Gr€enrcoft protd buildjngs 70 taei abovethe nrain bus platform. fton ultraviolct-raydamageand relieve lord, neanwhne,has beena corpo lhe problen of fluciuting tenperatures rute real estateinnovator Its one acre that can dmage roofing. ReHrche6 g.een nrof atop the ormal.€r's Prehicr liom the UniE6ity of Californiaat Davis Auto c.ou! he.dquarteB in lrvine, .eportedthat geen rcofscan"doublethe Calit in 2001wasthe first lord build- life of a roof ftom 15yea6 to 30 yexsl' ing to rceive LEEDcertificationand the > stotuat r .aptutu ad pollnnot fi6t lEED-certfied proje.t in Orange flndnof: Gteen roofs act as a fiLter CouDqrThe 10.aade "living roof" on for nany airborne pollutarts that fall Fordk Dearborn,Mi.h. buck plant is rhe with the rain. A greenroof surfaceof 3 to s inchesof soil or Browing nediuh absorbs7s9oof rainf.lls that areone'half Behind thecurve inch or less.This "sponge"etrecteduces While a 2005 2006 survel by creen stormwaterrunolt and helpsrelie'e tle Roofs for Heahhy Cities estimatedthe pre$ure on urbd storm-dfrin q tcns. amount of U.S.greenroofsgrN by 25Eo > Inprcwd ab qualitf; Crcen rcors ftom the yedrbefore, represeDtingmore filter air by absrbing and ()nrelting than 3 million sq. ft., the U.S.is still cdrbon dioxide and producing or:l€en. playingcatch-upto other nations.Tolqo Researchindicatesthat a I squr meter now requires200,6of roof surfacesto bc plot of g€.ss€D renrove0.2kilogrms of green.ln CennaDy,7Eoof roof spaceis airbone particulatesftoD the air U.S.citiesarecreatinggrerioof inentives, led 104
NREI May2008
by hunicjpalities such as chicaso, New Yorlq Cambnd€e,Mass.,and Portland, Orc. Chicagoprovids a 50Eomatching giant for adding gren roofs to sisting private-sctor buildingsdowDtown.
Assessing thecosts G.eer roofs carry higher upftont costs, but rcsearcheBindicat€ they are com petiti\e on a life cyd€ basisbecauk of .edued maintenmce and repla.em€nt costs.The Cjq. ol Portland estimatesa ns grreen roof costs$l to $6 moreper sq.ft. than. standardrooi Although energyeffrciencywill offset olerational .osts. developes typically have not ben ablc to incoporite tbe highercostsinto the prcject'spro forna. Greenrool ownm canbredkevenon upfront cosrsin five to l0 vearsbasedon energysavingsdd naintenance.A study bt' the Unilersity of Michiganconcluded that the averagepatbackpcriod for more extenslvegteenroofs wasabout 20 yea.s. In otber'Nords,gren roofs not only pencil.theycan payotr iD long-tem cost savingsand enviroDmentalbenefits. I
