Das Passivhaus

The term passive house (Passivhaus in German) refers to the rigorous, voluntary, Passivhaus standard for energy efficiency in a building, reducing its ecological footprint. It requires the creation of extremely well-insulated, airtight building envelopes and the controlling of other energy uses in the house such as water heating, appliances and lighting.

The Passivhaus movement started in Germany in the early 1990s. According to performance standards set by the Passivhaus Institute in Germany, the building can’t consume more than 15 kilowatt-hours per square meter in heating energy per year (equivalent to 4746 BTU per square foot per year). This typically requires that the wall, roof and floor insulation must be between R40 and R60. The building can’t leak more air than 0.6 times the house volume per hour. An energy recovery ventilator provides a constant, balanced fresh air supply. Basically, if a house fulfills all the Passivhaus requirements, the goal is that fuel costs will be zero and it doesn’t need a furnace anymore.

Although Passivhaus standards are difficult to achieve, I think that setting the bar purposely high is a good thing. So far, setting firm targets for reducing energy standards and switching to renewable energy sources has moved Europe onto the forefront of renewable energy technologies. Most of the innovations today come from Europe, and EU countries are slowly but steadily moving towards fossil fuel independence. The high passive house standards will also most likely act as incentives for builders and architects to reach those standards or even come up with a mainstream solution for a zero-energy house.

As of August 2010, there were approximately 25,000 certified passive houses in Europe, while in the United States there were only 13. As with so many other green innovations and leading-edge building designs as well as with the widespread use of renewable energy, the question is why is the US lagging so far behind? I think you can guess the answer(s) to that. For now, let’s just acknowledge that the technology is here and ready to use. We shouldn’t stop and be satisfied with LEED certifications because we can do better.