November 26, 2015
Observer Classics: Sustainable Housing and Communities: Industrialized Housing
The modern era of factory-built housing began during the Second World War. Homes were built in a way that would take as little material away from the war effort as possible.
These days, the most common forms of factory-built housing are referred to as manufactured and modular homes.
These complete factory-built houses are delivered to their final destinations and placed onto wood or concrete-block piers (to create a crawl-space) or on full-depth basement foundations. Cabinets, flooring, appliances and electrical and plumbing systems are installed and ready to be connected to municipal utilities networks. Homes are built in compliance with a series of standards and are certified before leaving the factory.
About 14.5% of all single-family housing starts are manufactured homes.
Annual building residential starts,1 Canada, 2004 – 2014
Annual building residential starts,1 Canada 2004 – 2014
||Annual Factory-built, single-detached starts
||Share of all single-detached starts
Factory-built modules are transported and assembled onsite and typically placed on full-depth basement foundations. Modular houses are subject to the same codes as site-built homes as it involves on-site construction processes.
In other housing processes, prefabricated panels are often used for walls, floors, and roof assemblies. Manufacturers have developed approaches to interlock the panels together so that the joints are air tight. With panelized construction, the outer walls can go up in as little as one day leaving a weather tight home for the trades to work in focussing on interior completion.
Engineered wood products perform better than traditional cut lumber. They are less susceptible to warping, shrinking, and twisting, and they reduce the impact of residential construction on our forests.
Other housing components that are commonly prefabricated include
- window assemblies,
- door assemblies,
- kitchen and bathroom pods
Producers of manufactured homes sell through retailers or dealers whereas modular housing producers increasingly sell through on-site builders, often with the producer and the builder sharing the credits in the promotion of the project.
|Shorter on-site construction time
||Larger capital/high fixed costs vs. site-built houses
|Precision construction and quality control
||Transportation freight costs and restrictions
|Potential for improved energy efficiency
|Reduced waste generation and improved
|Easy to disassemble and reconfigure
|Labour cost advantages and bulk buying power
|In-house design and development
For a more in-depth discussion seeSustainable Housing and Communities — Industrialized Housing from the 2013 Canadian Housing Observer.