Applying Passive House to a Century-old Building

We’ve mentioned a few residential retrofits – including a couple of projects underway in Northern California – whose energy efficiency goals are linked to the Passivhaus standard. Some are intended to approach the standard, others clearly are designed to meet it and attain certification from the Passive House Institute U.S.

The JP Green House is headed for the latter. The project is an ambitious one, in large part because this triangular building – which once featured Jack’s Country Store on the ground level and apartments on the second floor – has been a fixture in Boston’s Jamaica Plain neighborhood for 100 years. Its current owners, Ken Ward and Andrée Zaleska, intend to live upstairs with their three children and use the former commercial space for community activities, including Passivhaus demonstration tours and support programs for 350.org, an advocacy group for solutions to climate change.

Documented in detail
The project also has its own website, http://jpgreenhouse.org, that includes photographs and a video tour that highlights construction details in the 1,850-sq.-ft. two-bath house. Ward, Zaleska, and the kids (aged 7, 9, and 10) already are living in the building, which features a large, open space on the second floor where screens and curtains are positioned for privacy.

The builder doing the retrofit, Placetailor, based in nearby Roxbury, used a combination of cellulose and 2-in. foam board to insulate the exterior walls to just over R-50 and the roof to R-63. Placetailor principals Simon Hare (whose retrofit of a 150-year-old house in Roxbury was noted by GBA in a post last August) and Declan Keefe are now focused on sealing whatever leaks might remain before doing final blower-door tests and applying for Passive House certification. As Ward and Zaleska said in an email to GBA, they’re getting very close to the results they want.