It’s not realistic to abandon our cities in pursuit of a sustainable lifestyle. We’ve spent the past century developing a crucial infrastructure that our increasingly urban population depends upon.New urban developments, such as the Foundry lofts, heated by geothermal taps and the Netzero townhouses prove that energy efficient housing is viable for future construction.But the majority of Toronto’s urban development occured during wartime and postwar booms, when coal energy was cheaply available. The 400,000 homes across Toronto produce an average of 11 tonnes of carbon emissions every year. Condos and apartments tend to fare even worse per person.The Now House was a winning entry in a sustainable housing initiative launched by the Canada Mortgage Housing Corporation.Earlier this year, the Now House design team contacted home owner Lawrence Gauthier to use his 60-year-old home as an example. The Royal Bank of Canada funded the $85,000 renovation. They spent six months transforming his East York house into a near zero- energy home. Half a roof of solar panels provide most, if not all, the energy required to operate the appliances while solar water heatings and a complex system of heat recapturing improve the house's efficiency.The real coup in the Now House design is not in the energy production, but in its energy conservation. Energy is conserved through efficient spray-on insulation that essentially seals the house in a plastic container. Heat lost through waste water is recaptured through pipe networks that redistribute the warm water into the floors and walls.Once hooked up to the grid, Gauthier’s house will be able to sell power back to the city grid at 42 cents per kilowatt, over double the average rate Toronto power charges homeowners. Less