The GBA Conversation: The Building Scientist’s Home—a Conversation with Allison Bailes

Building scientist Allison Bailes, founder of Energy Vanguard and author of "A House Needs to Breathe … or Does It?," recently talked about his own 1961 house near Atlanta, which has turned into an ongoing home-improvement project. Even someone who studies buildings for a living has run into the same problems many homeowners face.

One issue was the attic. Years earlier, the roof had been insulated with open-cell spray foam, but Bailes found the job was done poorly. In some spots the foam was much thinner than it should have been, leaving gaps that let air leak through. The lesson he draws from this is a simple one: even experienced people can get burned if they assume insulation or other work was installed correctly. It pays to have work checked rather than just trusting it was done right.

On the mechanical side, Bailes replaced his old gas furnace and air conditioner with Mitsubishi inverter-driven heat pumps, a type of heating and cooling system that adjusts its output automatically rather than switching simply on and off. The conversation also touched on other projects at the house, including balanced ventilation, radon mitigation, and basement remodeling, though details on those weren't spelled out.

The bigger takeaway from his experience is about verification: quality control matters as much as the equipment or materials chosen, whether it's spray foam, an HVAC system, or general remodeling work. Problems tend to hide until someone checks closely, which is worth keeping in mind for anyone evaluating past work on their own home.