tags: energy efficiency, extensive green roof, high efficiency boilers, hubbard park apartments, hvac efficiencies, photovoltaic panels, . hugh garner housing co-operative; photo by aaran mckay/modern toronto, courtesy. urban design in the time of climate change: making a friend of floods – the globe and mail. the vegetation growing on toronto city hall green roof. project_sample1. prev next green roof rainwater collection. flatiron building with red brick and green roof.