New homes in Ontario will have to meet the highest energy-efficiency standards in Canada under new building-code provisions that require improvements in insulation levels, windows and furnace efficiency. The requirements will become effective in stages between now and the end of 2011. According to a report in the Globe and Mail, when fully implemented, the changes will increase the cost of a typical 2,000-square-foot gas-heated home in the Toronto area by up to $6,600, while cutting energy use about 35 per cent from current construction standards. The changes were lauded by Energy Minister Dwight Duncan, who said the construction of more efficient homes will help the province reduce its power use, a prime goal in Ontario where electricity shortages are a threat during periods of high air-conditioning use. Over the next eight years, the new measures will save the equivalent of enough energy to run about 380,000 homes and cut greenhouse-gas emissions by about the same amount as taking 250,000 cars off the road, according to the Ministry of Municipal Affairs and Housing.