from the ground up - The Tyee

‘Green building is Passivhaus’“Forget Energy Star and LEED,” the influential blogTreeHugger declared last year, “Green building isPassivhaus.”Among Europe’s more than 25,000 certified Passivhausbuildings are homes, school, office buildingsand a supermarket. And a growing number of localgovernments are incorporating variations of the Passivhausstandard into their building codes.Among the two-dozen-odd American Passivhaus projectsare this Salt Lake City home, and this New YorkCity office building.Canada, on the other hand, has turned its back on theSaskatchewan Conservation House, in much the sameway it abandoned the Avro Arrow and the TurboTrain.There is only one certified Passivhaus in Canada.The boxy first-generation Passivhaus buildings haveevolved into elegant suburban apartment buildingssuch as the one shown above in Bern, Switzerland,and natural country homes such as this one in France.Still on the boards is a Passivhaus tower in Austria. At30 stories, it promises to become the tallest woodenbuilding in the world.The Passivhaus standard has taken root in the U.S.more recently.Semantic confusion may partly explain the delay.Since the 1970s, the phrase “passive solar house” hasbeen used in the U.S. and Canada to describe houseswith extra thermal mass and big south-facing windows.Such homes are the antithesis of Passivhaus.Indeed, after decades of computer modeling and fieldmonitoring, engineers at the Passivhaus Institute haveconcluded that passive solar design is far less significantthan airtightness and insulation value. Nonetheless,aging advocates of that problematic designapproach insist on using the terms interchangeably,thereby fostering confusion. The first building in theU.S. that aimed to meet Passivhaus standards was ahome built by architect Katrin Klingenberg in Urbana,Illinois, in 2003. Klingenberg subsequently foundedthe nonprofit Passive House Institute US.Klingenberg’s houses are remarkably affordable, costingonly about 10 per cent more to build than comparablecode-minimum construction. “The real costadvantage occurs... when the standard HVAC systemcan be eliminated. It is then replaced by a smallerventilation system, a so-called fresh-air furnace. Thissystem’s significantly reduced ductwork is used todeliver the remaining 10 per cent of heating and coolingneeds.”40