The little mid-coast Maine town of Belfast is unusual in a variety of ways, including one that you wouldn't necessarily expect: Belfast is home to not one, but two high-performance builders who are leaders in superinsulated Passive House construction. Each builder is crafting houses that far surpass the performance of the typical Maine home, but they're pursuing their goals with different business models and different technical approaches.

GO•Logic, Inc., a partnership between architect Matt O'Malia and builder Alan Gibson, is wrapping up construction on a 36-unit cohousing project in Belfast, involving 12 separate buildings constructed using a combination of stick framing and structural insulated panels. EcoCor, Inc., run by builder Chris Corson, is building single-family Passive House homes on scattered sites in and around Belfast, and is ramping up an operation to panelize the system Corson developed (which incorporates wood I-joists into the wall assembly and relies extensively on advanced fabrics and air-sealing tapes).

EcoCor's and GO•Logic's advanced wall systems are featured in a December feature article in the Journal of Light Construction, including details of the integration between the walls and their respective roof and foundation systems (the story also includes two other solutions to the above-code envelope puzzle by architect-builder teams in Connecticut and Vermont). Here's an on-the-job preview of the two Maine solutions.