Manitoba Hydro Place

Manitoba Hydro Place

Paul Hultberg/KPMB Architects via Bloomberg

The exterior of Manitoba Hydro Place, in Winnipeg, Canada, is dominated at its northern end by a tall "solar chimney" that uses the buoyancy of hot air rising to draw exhaust air out of the building. It is one of many tactics this power-company headquarters uses to maintain energy consumption at about about one-third American commercial-building averages.