The debate rages about the German Passivhaus guidelines applicability to the North American market. Does a program developed in a temperate European climate work in the extremes of Canada or Florida; what are the relative merits of the various metrix used for window U-values, air infiltration, or even floor space; which approach is better?
Waldsee, Minnesota uses 85% less energy than a house built to Minnesota building codes. The fine points of discussion have to do with the lack of cooling need in central Europe, the measuring of the living area, the cost/benefit of energy consumption vs energy generation, etc. If you want the details, log into one of the many fine discussions, (JLC Online, BuildingScience.com, GreenbuildingAdvisor.com).
From the sidelines, I rejoice in this very well reasoned, and building science-based debate. With Passive House groups forming all over the world, this is becoming international movement, more organic in nature than the USGBC, or the International Code Council (read U.S.). This is a truly consensus- based acceptance of a concept - uniting the believers and builders of low to zero energy footprint housing. It doesn't try to be all things sustainable - but sticks to the core challenge - energy. The rest of the issues are intrinsically linked and tend to follow anyway.
I’m all for the debate. Introducing Passivhaus, the Minergie Standard (Switzerland), and all the other successful worldwide super energy standards brings the North American discussion into the global sphere, and introduces goals which are way beyond Energy Star/ Energuide (a mere 15 – 20% better than code). As a public and construction industry, we have believed that the obstacles were too great to achieving net-zero goals on a wide scale. Maybe it’s time for a major rethink.
This exposure to other country's building environments also shows us that our building materials are behind the times. For example, heatmirror film for window was first developed in the US in the 70’s, yet only a handful of window companies use it. Thank you, Canada, for finally manufacturing fiberglass windows. Our Velux skylights are less energy efficient than Velux manufactured in Europe. Our HRV, HVAC and water heater systems are generations behind the developments in Japan and Europe. We don’t need to wait for technology to be developed – we just need to start importing it - or change our own manufacturing.
So let the debate rage. Let’s learn from others and then figure out the best way to reach our own net-zero houses - not one house at a time- but whole subdivisions – and eventually ALL houses.