Inclusionary Housing Ordinance

In its adopted 2023-2031 Housing Element Update (HEU), the Town has identified that it will pursue an inclusionary housing program that would require a multifamily development to provide 20% of the units at income levels that meet specific affordability levels. However, the Town has not yet adopted this program. City Council will consider the inclusionary housing ordinance adoption in February 2024. With the passage of an inclusionary housing ordinance, Atherton will join other San Mateo County cities, including Menlo Park, Redwood City and Foster City.

The inclusionary housing ordinance may require new multifamily residential projects to set aside a percentage of units for affordable housing. The Atherton City Council is still working to determine what those percentages should be and how to distribute those requirements across income brackets. Residents are invited to share their thoughts on the inclusionary housing ordinance by emailing

POTENTIAL Affordable Multifamily Units with a 20% Requirement for Affordable Units

AddressLot Size (acres)
No. of Units (At density of 10 units per acre)No. of Affordable Units
23 Oakwood1.6163
999 Ringwood0.992
352 Bay Road0.9292
318 Bay Road0.9492
296 Bay Road0.9392
175 Ravenswood1.1112
185 Ravenswood1.1112
197 Ravenswood1.0102

Atherton’s efforts to provide opportunities for affordable housing are about more than just providing housing, but they aim to build a vibrant, engaged community. By offering housing options at various income levels, the Town can ensure that educators, nurses, civil servants and others who contribute significantly to our community’s health and well-being have the opportunity to call Atherton home.

Why does Atherton need an inclusionary housing ordinance?

Attracting the Best and Brightest to Atherton

Atherton relies on essential workers, such as teachers, healthcare professionals and police officers to provide essential services for every member of the community. An inclusionary housing ordinance will help our Town attract the best and brightest professionals to fill these roles by providing more opportunities for convenient and affordable housing close to where they work.

Meeting State Requirements for Housing Diversity

In the spirit of compliance, Atherton is embracing HCD’s directive to allow for multifamily developments to provide affordable housing opportunities to the community. In doing so, the Town demonstrates its commitment to aligning its efforts with HCD’s stated objective of increasing the supply of affordable housing across California.

What does affordable housing mean in San Mateo County?

In San Mateo County, the income thresholds for affordable housing are determined by the Area Median Income (AMI) and household size. San Mateo County’s AMI for a household of four is $175,000 per year. The Town is currently considering affordable housing requirements for new multifamily developments in the moderate, low and very low-income categories. 

Area Median Income (AMI) Table for San Mateo County

Income Category
Income Limits by Family Size

Very Low (50% AMI)
Low (80% AMI)$104,400
Median (100% AMI)$122,500
Moderate (120% AMI)$147,000


Next Steps

The City Council is working with Town staff, HCD officials and Atherton residents to determine the appropriate requirements for affordable housing in Atherton. See below for important milestones related to Atherton’s inclusionary housing ordinance.

  • February 2024: City Council to consider inclusionary housing ordinance
  • Late February/Early March 2024: City Council to determine sites for multifamily housing development