The GBA Conversation: Even Building Scientists Face Challenges at Home

Kohta Ueno, a building scientist who co-owns Building Science Corporation, lives in an ordinary top-floor apartment in a 1909 triple-decker in Boston, not a showcase energy-efficient home. His building has blown-in cellulose insulation, aging replacement windows, a tricky roof, and mechanical systems that were never designed with energy upgrades in mind. That makes his home a lot like the older houses many people actually live in. Rather than trying to fix everything at once, he has spent more than ten years making small, practical improvements as chances come up, treating each project as a trade-off between performance, convenience, and cost.

One example: his water heater sits in the basement while his apartment is two floors up, so every time he wanted hot water, he had to run the tap 30 to 45 seconds while it cleared the pipes. He installed a demand-controlled recirculation pump, a device that pushes hot water through the line only when needed, so it arrives faster without wasting water. But the fix created a new problem: during cold-water laundry loads, pressure changes let hot water leak backward into the cold pipes. He solved that with a motorized check valve, a small part that blocks water from flowing the wrong way.

The lesson for any older home: even straightforward upgrades can have side effects, and retrofitting a house often means solving one problem at a time rather than aiming for a perfect system all at once.