Multifamily Housing

Multifamily housing is characterized by multiple units in a single building or connected by shared walls. It can be developed at a range of heights and densities, from low-rise duplexes to high-rise apartment complexes, and can be rental or ownership housing.¹ Multifamily housing can be built at complementary scales and character to the surrounding neighborhood, whether single family residential or high-rise commercial/mixed-use. Multifamily housing types may include:

• duplexes, triplexes, fourplexes
• bungalow courts
• townhouses, garden apartments
• multistory apartment buildings
• high-rise apartments and condominiums

Multifamily housing is necessary to providing affordable units, particularly in high-cost housing markets. The majority of subsidized affordable housing is provided through multifamily development types, which use the land and building infrastructure more efficiently than single family detached housing.

Multifamily developments can be entirely affordable, or mixed-income. They tend to have a range of unit sizes, from studios to three-bedrooms. Affordable multifamily developments often offer amenities such as childcare centers, playgrounds, and community gathering spaces, and may also offer resident services such as case management, vocational development, financial literacy, or English as a Second Language classes.

One common barrier to building multifamily housing is a shortage of land zoned for multifamily residential uses. In jurisdictions that do not have sufficient multifamily zoned land, a housing overlay zone can be used on top of existing land uses to allow housing development in a particular location without needing to amend the general plan and zoning ordinance.

As demographics and consumer preferences shift, demand has grown for walkable communities with a mix of uses, but this type of development is undersupplied. In particular, more housing is needed in the “missing middle”—housing types between single family detached subdivisions and high-rise apartments in terms of scale and density.

There is a severe shortage of housing affordable to low- and moderate-income households within San Mateo County. The following jurisdictions have subsidized affordable housing complexes:

• Multifamily housing provides more efficient use of land and building infrastructure than single family development types.
• Multifamily housing can be built at a range of heights and densities, and at complementary scale and character to surrounding neighborhoods.

• New affordable multifamily housing is often indistinguishable from, and built alongside, market-rate housing.
• Affordable multifamily properties may have a variety of affordability levels, such as units serving moderate, low, and very low income households, or may focus on one income band, such as 60-80 percent of Area Median Income.

• Develop informational resources: Create “visualizing density” graphics to illustrate how various densities (dwelling units/acre) look from the street and from above – in particular, show lower-density multifamily developments that are suitable for residential neighborhoods.
• Educate your community: Demonstrate how density makes certain services and amenities viable – how various density thresholds make transit, neighborhood retail, or better retail offerings (e.g. new cafes and restaurants) possible.
• Engage in-person: Host “tour of homes” walking tours or open houses to showcase recent affordable multifamily projects.
• Highlight success stories: Feature stories of residents in local affordable multifamily projects.

• Tool: Multifamily Development, Housing Innovations Program, Puget Sound Regional Council