Mu Januwale 2010, Toronto idakhala mzinda woyamba ku North America kufuna kuyika madenga obiriwira pazamalonda, mabungwe, ndi mabanja ambiri mumzindawu. Sabata yamawa, chofunikirachi chidzakula kuti chigwire ntchito ku chitukuko chatsopano cha mafakitale.

Mwachidule, ¡°denga lobiriwira¡± ndi denga lomwe lili ndi zomera. Denga lobiriwira limabweretsa zabwino zambiri zachilengedwe pochepetsa kutenthedwa kwa chilumba cha m'matauni komanso kuchuluka kwa mphamvu zomwe zimayendera, kutengera madzi amvula asanasefuke, kuwongolera mpweya wabwino, ndikubweretsa chilengedwe komanso kusiyanasiyana kwachilengedwe m'matauni. Nthawi zambiri, madenga obiriwira amathanso kusangalala ndi anthu monga momwe paki ingakhalire.

Zofunikira za Toronto ¡¯s zili m'malamulo apatawuni omwe amaphatikiza miyezo ya nthawi yomwe denga lobiriwira likufunika komanso ndi zinthu ziti zomwe zimafunikira pakupanga. Nthawi zambiri, nyumba zing'onozing'ono zogona ndi zamalonda (monga nyumba zosachepera zisanu ndi chimodzi zazitali) ndizosaloledwa; kuchokera pamenepo, nyumbayo ikakula, gawo la denga la denga liyenera kukhala lalikulu. Kwa nyumba zazikulu, 60 peresenti ya malo omwe alipo padenga ayenera kukhala zomera.

Kwa nyumba zamafakitale, zofunikira sizofunikira. Lamuloli lidzafuna kuti 10 peresenti ya malo omwe alipo padenga la nyumba zatsopano zamafakitale aphimbidwe, pokhapokha ngati nyumbayo imagwiritsa ntchito ¡°zida zofolerera zoziziritsa¡± pa 100 peresenti ya malo a denga omwe alipo ndipo ili ndi njira zosungira madzi amvula okwanira 50 peresenti ya mvula yapachaka (kapena mamilimita asanu oyambirira kuchokera kumvula iliyonse) pamalopo. Panyumba zonse, kusiyanasiyana kwa kutsata (mwachitsanzo, kuphimba denga laling'ono ndi zomera) kungafunsidwe ngati kuli ndi chindapusa (chotengera kukula kwa nyumba) zomwe zimayikidwa kuti zilimbikitse chitukuko cha denga lobiriwira pakati pa eni nyumba omwe alipo. Zosintha ziyenera kuperekedwa ndi City Council.

Mgwirizano wamakampani a Green Roofs for Healthy Cities adalengeza kugwa komaliza m'mawu atolankhani kuti zofunikira za denga lobiriwira la Toronto zidapangitsa kuti malo opitilira 1.2 miliyoni (113,300 square metres) a malo atsopano obiriwira omwe akonzedweratu pazamalonda, mabungwe, komanso nyumba zambirimbiri mumzinda. Malinga ndi bungweli, zopindulitsa zidzaphatikizanso ntchito zopitilira 125 zokhudzana ndi kupanga, kupanga, kukhazikitsa ndi kukonza madenga; kuchepetsedwa kwa madzi a mkuntho opitirira makyubiki mita 435,000 (okwanira kudzaza maiwe osambira okwana pafupifupi 50 a Olympic) chaka chilichonse; ndi kupulumutsa mphamvu pachaka kopitilira 1.5 miliyoni KWH kwa eni nyumba. Pamene pulogalamuyo ikugwira ntchito nthawi yayitali, phindu lidzawonjezeka.

Chithunzi cha triptych pamwambapa chinapangidwa ndi ophunzira ku yunivesite ya Toronto kuti awonetse zosintha zomwe zingachitike kuyambira zaka khumi kupita patsogolo pansi pa zofunikira za mzinda¡¯s. Lamuloli lisanakhazikike, Toronto inali yachiwiri pakati pa mizinda yaku North America (pambuyo pa Chicago) pamlingo wake wonse wokhala ndi denga lobiriwira. Zithunzi zina zotsagana ndi positiyi (sunthani cholozera pazithunzizo kuti mumve zambiri) zikuwonetsa madenga obiriwira panyumba zosiyanasiyana za ku Toronto, kuphatikiza pulojekiti yowonekera pagulu la City Hall¡¯s podium.