NgoJanuwari ka-2010, iToronto yaba sisixeko sokuqala eMntla Melika ukufuna ukufakelwa kophahla oluluhlaza kwiindawo ezintsha zorhwebo, zezikhungo, kunye neendawo zokuhlala ezineentsapho ezininzi kulo lonke isixeko. Kwiveki ezayo, imfuneko iya kwanda ukuze isebenze nakuphuhliso olutsha lwemizi-mveliso.

Ngamafutshane, uphahla oluluhlaza oluyi-¡°± luphahla olutyalwe izityalo. Uphahla oluluhlaza luvelisa iingenelo ezininzi zokusingqongileyo ngokunciphisa isiphumo sesiqithi sobushushu basezidolophini kunye nemfuno yamandla ehambelanayo, ukufunxa amanzi emvula ngaphambi kokuba aphume, ukuphucula umgangatho womoya, kunye nokuzisa indalo kunye nokwahlukahlukana kwendalo kwiindawo zasezidolophini. Kwiimeko ezininzi, uphahla oluluhlaza lunokonwatyelwa luluntu njengokuba kunjalo ngepaki.

Iimfuno zaseToronto ziqulathwe kumthetho kamasipala oquka imigangatho yokuba kufuneka nini uphahla oluluhlaza kunye nezinto ezifunekayo kuyilo. Ngokubanzi, izakhiwo ezincinci zokuhlala kunye nezorhwebo (ezifana nezakhiwo zeeflethi ezingaphantsi kwemigangatho emithandathu ubude) azinazo; ukusuka apho, okukhona isakhiwo sikhulu, kokukhona inxalenye yophahla enezityalo kufuneka ibe nkulu. Kwizakhiwo ezikhulu, ama-60 ekhulwini esithuba esikhoyo eluphahleni kufuneka sibe nezityalo.

Kwizakhiwo zoshishino, iimfuno azinzima kangako. Umthetho wedolophu uya kufuna ukuba i-10% yendawo yophahla ekhoyo kwizakhiwo ezintsha zoshishino igutyungelwe, ngaphandle kokuba isakhiwo sisebenzisa "izinto zokuphahla ezipholileyo" kwi-100% yendawo yophahla ekhoyo kwaye sineendlela zokugcina amanzi emvula ezaneleyo zokubamba i-50% yemvula yonyaka (okanye i-5 mm yokuqala kwimvula nganye) kwindawo. Kuzo zonke izakhiwo, umahluko wokuthobela imithetho (umzekelo, ukugubungela indawo yophahla encinci ngezityalo) unokucelwa ukuba uhamba neentlawulo (ezibalulekileyo kubungakanani besakhiwo) ezityalwe kwizibonelelo zophuhliso lophahla oluluhlaza phakathi kwabanini bezakhiwo ezikhoyo. Umahluko kufuneka unikwe yiBhunga leSixeko.

Umbutho wezoshishino iGreen Roofs for Healthy Cities ubhengeze ekwindla ephelileyo kwingxelo yabezindaba ukuba iimfuno zophahla oluluhlaza lwaseToronto sele zibangele indawo entsha eluhlaza engaphezulu kwe-1.2 yezigidi zeemitha zesikwere (iimitha zesikwere ezili-113,300) ecwangcisiweyo kuphuhliso lwezindlu zorhwebo, lweziko, kunye nolweentsapho ezininzi kwisixeko. Ngokutsho kombutho, iingenelo ziya kubandakanya imisebenzi yexesha elizeleyo engaphezulu kwe-125 enxulumene nokuvelisa, ukuyila, ukufakela kunye nokugcinwa kophahla; ukuncitshiswa kwamanzi emvula angaphezu kwe-435,000 cubic feet (aneleyo ukuzalisa amachibi okudada angama-50 e-Olimpiki) minyaka le; kunye nokonga amandla ngonyaka okungaphezulu kwe-1.5 yezigidi ze-KWH kubanini bezakhiwo. Okukhona le nkqubo isebenza ixesha elide, kokukhona iingenelo ziya kwanda.

Umfanekiso we-triptych ongentla wenziwe ngabafundi kwiYunivesithi yaseToronto ukubonisa utshintsho olunokuthi luvele emva kweminyaka elishumi yenkqubela phantsi kweemfuno zesixeko. Ngaphambi komthetho, iToronto yayiyeyesibini phakathi kwezixeko zaseMntla Melika (emva kweChicago) ngobungakanani bayo bonke bophahla oluluhlaza. Eminye imifanekiso ehamba nale posi (hambisa isalathisi sakho phezu kwayo ukuze ufumane iinkcukacha) ibonisa uphahla oluluhlaza kwizakhiwo ezahlukeneyo zaseToronto, kubandakanya neprojekthi yokubonisa efikelelekayo esidlangalaleni kwiqonga leHolo yeSixeko.