Off-site construction is a large category of building which involves any process which – instead of being performed on a construction site, is instead performed in a facility not connected to the construction site, where conditions are often climate controlled, and repetitive processes such as framing walls, insulating, and installing other layers of the building enclosure can be accomplished more efficiently.
While the fabrication of windows and doors could be considered an element of off-site construction, today the term usually applies to the fabrication of components in three distinct categories:
Where wall, roof, and floor panels are constructed and in some cases insulated and wrapped in special air and weather-protective membranes
Where complete 6-sided boxes are built in a factory, often with fenestration, services, and finishes installed. While these modules are limited by the restrictions on size from various transportation modes, multiple units can be stacked and configured to accomplish a larger building design.
Originally created in North America in the early 1900s, the kit home was an attempt to package all the materials required for to build a house, and deliver them at once, for homeowners to construct their own homes on site. While modern innovations to the kit home exist, these products have been largely discontinued due to a variety of factors.
Off-site construction today happens in warehouses as small as 1,000SF, where panels are fabricated with standard site construction tools, simple workstations, and little integration of computerized design and cutting tools, to those over 100,000SF operating multiple production lines, utilizing computerized cutting, insulating, and framing systems, and fabricating panels, modules, and even kitchens, bathrooms, stairs, and integrated HVAC systems.
Some of our favorite pioneers building ecologically minded homes with off-site construction methods include Baufritz, operating in Germany, Austria, Switzerland, Luxembourg, and the UK, and Bensonwood, operating in the northeastern United States.