Manufactured Homes, know as mobile homes, is a type of prefabricated housing that is largely assembled in factories and then transported to sites of use. The definition of the term is regulated by federal law (Code of Federal Regulations, 24 CFR 3280): "Manufactured homes are built as dwelling units of at least 320 square feet (30 m2) in size with a permanent chassis to assure the initial and continued transportability of the home." The requirement to have a wheeled chassis permanently attached differentiates "manufactured housing" from other types of prefabricated homes, such as modular homes. 

According to the Manufactured Housing Institute’s National Communities Council (MHINCC), manufactured homes are homes built entirely in the factory under a federal building code administered by the U.S. Department of Housing and Urban Development (HUD). The Federal Manufactured Home Construction and Safety Standards (commonly known as the HUD Code) went into effect June 15, 1976. Manufactured homes may be single- or multi-section and are transported to the site and installed.

Modern High-Performance Manufactured Homes:

While manufactured homes are considered to be affordable housing, High-performance manufactured housing uses less energy and therefore increases life-cycle affordability by decreasing operating costs. High-performance housing is not only energy efficient, but also attractive, functional, water-efficient, resilient to wind, seismic forces, and moisture penetration, and has healthy indoor environmental quality. Achieving high-performance involves integrated, whole building design, involving many components, not one single technology. High–performance manufactured housing should also include energy efficient appliances, such as Energy Star qualified appliances.

Difference from Modular Homes:

Both types of homes – manufactured and modular – are commonly referred to as factory-built housing, but they are not identical. Modular homes are transported on flatbed trucks rather than being towed, and lackaxles and an automotive-type frame. However, some modular houses are towed behind a semi-truck ortoter on a frame similar to that of a trailer. The house is usually in two pieces and is hauled by two separate trucks. Each frame has five or more axles, depending on the size of the house. Once the house has reached its location, the axles and the tongue of the frame are then removed, and the house is set on a concrete foundation by a large crane. Most modern modular homes, once fully assembled, are indistinguishable from site-built homes. Their roofs are usually transported as separate units, eradicating the telltale roof line of the factory built home.

Difference from IRC Codes Homes (site built):

Manufactured homes have several standard requirements that are more stringent than IRC coded homes.

Fire Protection:

A National Fire Protection Association (NFPA) study from July 2011 shows that occurrence of fires is lower in manufactured housing and the injury rate is lower in manufactured housing. The justification behind the superior fire safety is due to the following higher standard requirements:

  • The HUD standard requires a flame spread of 25 or less in water heater and furnace compartments.
  • The HUD standard requires a flame spread of 50 or less on the wall behind the range.
  • The HUD standard requires a flame spread of 75 or less on the ceilings.
  • The HUD standard requires a flame spread of 25 or less to protect the bottoms and side of kitchen cabinets around the range.
  • The HUD standard requires additional protection of cabinets above the range.
  • The HUD standard requires trim larger than 6″ to meet flame spread requirements.
  • The HUD standard requires smoke detectors in the general living area.
  • The HUD standard requires 2 exterior doors.
  • The HUD standard requires bedroom doors to be within 35 feet of an exterior door.