Accessory Dwelling Unit (ADU) & Jr. Accessory Dwelling Unit (JADU) Ordinance Update 

ADU and JADU - Image

REVISED:  March 30, 2020

LOCATION:  City-wide

APN:  City-wide

City of San Mateo

Phillip Brennan
Associate Planner
(650) 522-7218


On March 2, 2020, Staff updated City Council regarding changes to State Law associated with ADU/JADU development, as well as to discuss the limited areas of regulation which remain under the City’s discretion. Council provided Staff general direction to study a number of technical areas including a tiered minimum or “by-right” ADU size based on lot size; developing a maximum building height for ADUs and exemptions to address additional parking associated with ADU/JADUs; and exploring ways to expedite and streamline the permitting process. The Council agreed to continue banning short-term rentals on all ADUs, and to allow existing non-code compliant ADUs to remain provided they meet health and safety considerations. The Council was unanimous agreement that additional community outreach should be conducted by the City to ensure the community is informed on the recent changes to State Law.


•   City Council (Study Session): Meeting Materials and Video – March 2, 2020


Effective January 1, 2020, new state legislation (SB 13, AB 68 and AB 881) pertaining to Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs) came into law with the intended purpose of easing local zoning controls, reducing associated development fees, and streamlining the permit process. The new legislation expressly limits a local agency’s ability to regulate ADUs and JADUs, and puts most local ADU/JADU ordinances in conflict with the State’s new laws. Staff will be updating the City’s existing ADU/JADU ordinance to be compliant with the State’s and soliciting direction from the City Council regarding the limited areas which remain under local control.

Please click on the following link for more information regarding
Accessory Dwelling Unit (ADU) & Junior Accessory Dwelling Unit (JADU) development standards and plan submittal guide.