Entry Date:
March 27, 2019

Prefabricated Housing: Novel ways to prefabricate houses

Principal Investigator Lawrence Sass


Prefabricated homes, often referred to as prefab homes or simply prefabs, are specialist dwelling types of prefabricated building, which are manufactured off-site in advance, usually in standard sections that can be easily shipped and assembled. Some current prefab home designs include architectural details inspired by postmodernism or futurist architecture.

The word ‘prefab’ is not an industry term like modular home, manufactured home, panelized home or site-built home. The term is an amalgamation of panelized and modular building systems, and can mean either one. In today's usage the term ‘prefab’ is more closely related to the style of home, usually modernist, rather than to a particular method of home construction.

‘Prefabricated’ may refer to buildings built in components (e.g. panels), modules (modular homes) or transportable sections (manufactured homes), and may also be used to refer to mobile homes, i.e., houses on wheels. Although similar, the methods and design of the three vary widely. There are two-level home plans, as well as custom home plans. There are considerable differences in the construction types. In the U.S., mobile and manufactured houses are constructed in accordance with HUD building codes, while modular houses are constructed in accordance with the IRC (International Residential Code).

Modular homes are created in sections, and then transported to the home site for construction and installation. These are typically installed and treated like a regular house, for financing, appraisal and construction purposes, and are usually the most expensive of the three. Although the sections of the house are prefabricated, the sections, or modules, are put together at the construction much like a typical home. Manufactured homes, once placed on a permanent foundation, are considered the same as modular or site build homes for appraisal purposes.

(*) Manufactured homes are built onto steel beams, and are transported in complete sections to the home site, where they are assembled. Wheels, hitch and axles are removed on site when the home is placed on a permanent foundation.

(*) Mobile homes, or trailers, are built on wheels, that can be pulled by a vehicle. They are considered to be personal property, and are licensed by the Dept. of Motor Vehicles. "Tiny homes", which are gaining in popularity, are within this category. They must be built to the DMV code, and pass inspection for licensing.

Mobile homes and manufactured homes can be placed in mobile home parks, and manufactured homes can also be placed on private land, unless the land is within a subdivision whose CC&Rs prohibit manufactured housing.
Interior of a preserved prefab at St Fagans National History Museum, Cardiff, UK