Housing Policy Glossary

Accessory Dwelling Unit (ADU): These are smaller, self-contained residential units located on the same property as a single-family home. ADUs can be instrumental in increasing the affordable housing supply but are not a complete solution to meeting Atherton’s Regional Housing Needs Allocation (RHNA).

Affordable Housing: This refers to housing that is financially manageable for various income levels, where the housing cost is proportionate to household income. Housing will be considered affordable by the California Department of Housing and Community Development if it has at least 20 units per acre because higher density allows for lower-cost units. San Mateo’s 2021 Area Median Income (AMI) is currently $149,600 for a household of four. For comparison purposes, all figures below assume a household of four annual income.

  • Very-Low (Less than 50% AMI) = $91,350 or less
  • Low (Between 50%-80% AMI) = Up to $146,350
  • Moderate (Between 80%-120% AMI) = Up to $179,500

Association of Bay Area Governments (ABAG): ABAG helps local governments absorb growth and adapt to change while addressing sustainability, resilience and equity issues. Their services to members include research and analysis, education and outreach, and regional coalition coordination. ABAG’s expert data and tool resources and robust planning department build solutions on a wide range of issues including:

  • Land use
  • Housing
  • Environmental protection
  • Water resource protection
  • Disaster resilience
  • Energy efficiency

Builder’s Remedy: A provision in the California Housing Accountability Act (see Government Code Section § 65589.5(d). In California’s legal framework, a city that does not have a certified Housing Element must approve most housing projects that ensure at least 20% of the units are low-income, or all units are moderate-income.

California Department of Housing and Community Development (HCD): This state entity reviews local governments’ Housing Elements for compliance with state legislation. Approval from HCD is mandatory before integrating the Housing Element into the city’s comprehensive General Plan. A failure in compliance can result in decertification of a jurisdiction’s Housing Element, and furthermore, diminished control over future developments and potential financial penalties.

California Environmental Quality Act (CEQA): A statute that obligates state and local agencies to pinpoint and potentially mitigate the significant environmental impacts resulting from their operational decisions.

Density: This term denotes the quantity of residential units housed on a designated land parcel. The concept of density varies, and increased densities are often achieved via multi-story constructions on compact land parcels.

Density Bonus: A legal provision in California that permits developers to have additional residential units or building square footage and other development standard concessions, in exchange for the inclusion of affordable housing units in their projects.

Department of Housing and Urban Development (HUD): A U.S. federal entity overseeing national policies and programs that address the country’s housing needs, develop communities, and enforce fair housing regulations.

Environmental Impact Report (EIR): A document that illuminates the significant environmental ramifications of proposed undertakings, offering potential mitigation actions and outlining alternative project options for both the populace and decision-makers’ consideration.

General Plan: A strategic blueprint that steers a city’s enduring development, offering methodologies to oversee its diverse resources. The plan encompasses a collective vision and caters to the city’s distinct aspects and needs, divided into seven elements, each targeting a specific subject area.

Housing Element: This element, one among the seven state-compelled sections of a local General Plan, acts as a strategy for upcoming housing developments. It evaluates the present and future housing requirements of the community’s various economic segments and outlines objectives, policies, and action plans for housing preservation, enhancement, and creation. It is the only section of the General Plan that is subject to the State’s approval. The Housing Element follows an eight-year cycle and requires State certification every time.

Regional Housing Needs Allocation (RHNA): A state housing legislation that outlines the anticipated housing necessities for all cities and counties in California, revisited every eight years. Every jurisdiction is mandated to incorporate its RHNA into its Housing Element, ensuring zoning regulations and potential housing locations can cater to the allocated needs. HCD assigns each region a regional total and in the Bay Area, the Association of Bay Area Governments (ABAG) determines the methodology to equitably distribute the regional total throughout the region.

Zoning: A regulatory mechanism employed by most cities to designate permitted land uses within specific regions, stipulating aspects like building dimensions, spatial relationships to adjacent structures, and open spaces.