Maine has some of the oldest housing stock in the nation, and the old town of Bangor is no exception. The city boasts a collection of fine old homes built during the town's heyday as a center of the state's lumber industry, which boomed in the 1800s. And it has neighborhoods full of 1960s and 1970s split-level homes, raised ranches, and garrison colonials, all of them good candidates for a thorough energy upgrade. But with home prices flat or even falling in the area, an investment in a comprehensive energy upgrade can be a tough sell.

On the Job: A Deep Energy Retrofit in Bangor, Maine

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House Revivers of Bangor, Maine, strip and re-clad an old house, aiming for net-zero performance.

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But that situation hasn't stopped Bangor-based House Revivers from carving out a niche in the energy-upgrade market. The company has a six-home zero-energy development underway on Fern Street in Bangor (one of the city's so-called "tree streets," with names like Maple and Birch, where walkability and a neighborhood feel are attractions). And this month, JLC caught up with House Revivers at the job site where David Kelly, son of company founders Bob and Suzanne Kelly, is working with skilled carpenters Jay Kelleher, Sonny Searles, and Rick Martin on a complete gut-rehab of an old Bangor wood-frame house. The goal is to make the house airtight and well-insulated enough to be heated with a pair of mini-split heat pumps (one upstairs and one down), with enough solar photovoltaic panels on the roof to make as much power as the house needs every year.

JLC came along in time to see David Kelly applying Prosoco's wet flashing system to the old home's new window openings, and then to see Kelly and the crew installing new windows, beefing up the home's walls with exterior-applied Dow extruded polystyrene (XPS) insulation, and tying the sheathing into the windows with builder's tape. Take a look.