Habitat for Humanity, Washington DC
An airsealing team of volunteers achieves 0.2 ACH50
Habitat for Humanity of Washington DC is proving itself to be a leader in affordable Passive House building. After incredible coverage from National Geographic (wherein they suggest the homes may be among the most Earth-friendly ever built), we had to visit to get the details from the builder's perspective. The all-volunteer construction team was led by Dan Hines, one of the few full-time employees involved in the project. As the point of continuity, Dan masterfully directed the operation to achieve a remarkably good blower-door number - 0.2 ACH50 on the first set of houses, anticipating similar numbers on the units in process.
The secrets to success on this project boil down to an attention to solid airsealing details, and the commitment to blower-door testing at every stage of the process. Testing early and often allows the crew to narrow down air leaks to a pinpoint, and tackle them while they are open and accessible. Here's hoping that Habitat for Humanity chooses to build on this success and spread the Passive House banner nation-wide.
Materials used for airtightness: