Stack effect is relentless: it is always working, when you’re awake or asleep, even during blackouts. And it feeds on itself.

"In order to maximize the buildable area on the infill lot, we had to go fairly deep and do some extensive shoring."

—Dan Whitmore of Hammer & Hand 

Offset the joints and seal the gaps to keep air leaks out of the thick walls

Windows cannot rest on the foam, so they hang from wood bucks

Letting the brick dry evenly is the key for old masonry walls that want to leak less energy

Window banks need to line up neatly for the trim to work out. Foam walls add the extra possibility of compressing the backing. So there's that.

A superinsulated sunroom might sound like an oxymoronic idea, but it is not. Just use triple glazed windows and thick foam over the wall framing and roof

A deep energy retrofit in Concord, MA illustrates everything you need to know to bring a house to energy überville

Built tight and verify. And then ventilate.

The final step: center it in the opening, and seal the perimeter