The new city hall in Cambridge, Ont., is registered to become the first LEED Gold-certified city hall in Canada. Because Cambridge is the largest urban area in Canada to rely on groundwater, designers at Diamond and Schmitt Architects, Toronto, made sure the hall conserved water. Features include a grey water system for the reuse of water captured on the roof, low-flow fixtures and dual-flush toilets in the restrooms, and permeable pavement in the plazas to retain storm water. The four-story, 85,000-sf hall also features a sky-lit atrium (pictured) with a full-height plant-wall bio filter—a vertical hydroponic system that acts as an indoor air purifier consuming air contaminants. Other green features include a vegetated roof, operable windows, radiant heat panels, and occupancy sensors.