GO Home traces its lineage to a Passive House prototype residence our parent firm, GO Logic, built in 2009. Dubbed the GO Home, the distinctively simple red house seems to have struck a chord, drawing coverage in numerous magazine articles, appearing on book covers, and generating a stream of client inquiries that shows no sign of slowing down.
That near-viral popularity led us to ask how we could deliver the same smart design and affordable Passive House performance not just in our local projects, but to clients everywhere. The answer: Panelization. After considerable research on prefab housing in North America and Sweden, we developed a system of prefabricating our building shells in sections—panels—combining our own Passive House construction details with innovative methods of factory production.
Instead of delivering stacks of building materials to a construction site and assembling them out in the elements, we construct exterior wall panels up to 30 feet long—as well as interior walls and wood floors—indoors, under climate-controlled conditions. The panels, complete with building wrap, windows and exterior insulation installed, are then delivered to the building site and craned into place on a foundation that has been constructed in advance. A prefabricated-truss roof follows, yielding a weathertight, air-sealed building shell in less than two weeks of on-site construction.
GO Home panelization employs exhaustively tested details and factory processes to speed production, maximize material efficiency, and guarantee that crucial air-sealing operations meet our standards. A 3D computer model of each Simple House design allows us to generate a specific plan for each panel, detailed down to the individual stud. Constructing walls panels on waist-high, movable platforms, rather than while kneeling on the ground or up on ladders, our crew works more efficiently and ergonomically than field-based carpenters.
Honed over several generations of built iterations, and tested under a Maine Technology Institute research grant, our exterior wall panels incorporate advanced building science and material technology to provide R-50 thermal performance, while passively managing moisture originating both outside and inside the building.
Each wall panel begins with 2×8 stud framing, which provides structural support for the building and accommodates a thick layer of dense-pack cellulose insulation (installed on site when the shell is complete). Zip System exterior sheathing with taped seams adds structural rigidity while providing a continuous air and moisture barrier. Building wrap, also carefully taped, adds a second air barrier and drainage plane, over which we apply 6 inches of Roxul rigid rock wool insulation. Noncombustible and hydrophobic, rock wool doesn’t degrade with repeated wetting and drying, and it doesn’t support insects or other pests. Wood strapping holds the exterior insulation in place, allowing it to breathe to the outdoors, and also serves as a nailing base for the siding that will be installed on site.
Using proven systems and materials, we seal the critical joints at window openings, between the foundation and exterior walls, and between the wall and roof structures, achieving blower-door test results as low as .6 air changes per hour at 50 pascals of pressure (ACH50), which meets the stringent Passive House standard.
As important as the quality and performance gains we’ve achieved with our panelization system, however, is the flexibility it affords. On the houses we build for our Maine clients, panelization permits greater control over schedule and delivery. And for projects outside of Maine, it allows us to offer Simple House design and Passive House performance in an off-the-shelf package that makes life easy for clients and their local builders.