I get asked a lot of questions about spray foam. Do I need an ignition barrier? Should I use open cell or closed cell spray foam? Will open cell spray foam really rot my roof? But the question I get…
I've seen some crazy things done to homes. It's usually someone's attempt to make things better. Sometimes that someone is a homeowner or other occupant. Sometimes it's a contractor. But it always seems to be a solution to a problem…
Ah, ventilation. One of the easier topics in building science. Everyone agrees: We need airtight houses. Airtight houses need mechanical ventilation. Build tight. Ventilate right. No problem! We're all on board. There's nothing to disagree about. Right? Ah, ventilation. One…
I've got a record of 14 blower door tests on my condo. Many of them were during home energy rater classes, as we'd bring them here for the confirmed rating they needed to complete. The early ones were horrible! But…
Passive house has a reputation for requiring ungodly amounts of insulation. It grew out of the superinsulation movement after all. If you're familiar with any passive house projects, you may be thinking about double-stud walls that are a foot thick…
In 2002, Katrin Klingenberg introduced the passivhaus program to North America when she built the Smith House in Urbana, Illinois. She had come to the US from Germany, where she studied architecture and got involved with passivhaus. But is this…
A lot of discoveries and research work over the past four decades have led to our current understanding of air leakage in buildings. I’ll mention a few here, but I want to focus on one: the MAD AIR paper by…
In Missouri for the ASHRAE conference, I took some time to visit with my Cajun baby sister the other day. As we were making our way to one of the local wineries outside of St. Louis, we saw a sign…
Last month while I was in Austin, homebuilder extraordinaire Matt Risinger gave me a tour of some of his projects. Afterward I wrote about something I saw on his new home construction site that was a sign of a good…
Condominiums and apartments present some serious challenges when it comes to providing ventilation for good indoor air quality. (I live in a condo that was built in 1970 with no whole-house mechanical ventilation, but that's another story.) In high-rise buildings,…