San Mateo County permits manufactured and modular homes in all residential zoning districts in the County. If a residence is legally allowed on a property, a manufactured or modular home is allowed. Modular and manufactured accessory dwelling units are also allowed, in addition to primary residences.

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What is a manufactured or modular home?

Manufactured and modular homes are built in a factory, transported to a building site, and assembled on site. They are built to established Federal and State standards, and inspected for safety and habitability after production. In general, modular homes are constructed in pieces in a factory and shipped to the building site for construction, while manufactured homes are entirely pre-constructed and shipped to the building site whole. The standards for construction of manufactured homes are established by the Federal Department of Housing and Urban Development, while the standards for construction of modular homes in California are established by the State of California.

With some exceptions in the case of modular or manufactured units placed in formally designated mobile home parks, manufactured/modular housing must still be affixed to a permanent foundation and served by permanent utilities in the same manner as any other unit. Manufactured/modular homes must also comply with all zoning and other regulations that would apply to a conventionally constructed house. However, the building standards for the construction of modular and manufactured homes are established at the State or Federal level, not by local building codes.

The Benefits of Manufactured and Modular Housing

Manufactured or modular homes are often significantly cheaper to purchase and construct on a property than similarly located conventionally-built homes. In addition, because inspection of manufactured and modular homes for compliance with building codes is performed by State inspectors, local planning and building fees are typically much lower than for other types of housing. (Note: local planning and building permits are still required for modular and manufactured housing. San Mateo County’s permitting process can be found on the Planning Department website.) Local inspection addresses only the installation of the unit on the site, utility connections, and compliance with zoning regulations regarding placement, size, height, and other applicable factors.

In addition, because they are factory-built, the construction of manufactured/modular homes is also often more energy and waste efficient than comparable conventionally-built homes.

Because it is generally both cheaper and easier to purchase and install a manufactured/modular home on a property than to purchase a conventionally-built home, this type of housing may provide a safe, affordable, and attractive option for the homebuyer in comparison to traditional “stick-built” housing.

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Manufactured and Modular Home Regulations

In California, construction of manufactured and modular homes is regulated by the California Department of Housing and Community Development. For manufactured homes, California implements standards established by the Federal Department of Housing and Urban Development.

Who builds manufactured homes?

A number of companies build manufactured and modular homes, in some cases selling them directly to the homebuyer, in other cases selling through various retailers. The County cannot provide an endorsement of any builder or retailer, but there are many established companies selling manufactured and modular homes in San Mateo County. Both manufactured and modular homes are readily available from a number of sources, in a variety of types, sizes and configurations that can be customized to meet the needs of the homebuyer and match the conditions of the building site and the applicable zoning regulations.

Additional Information