Menlo Park Accessory Dwelling Unit (ADU) Standards

        New laws were recently passed, and updates will be coming soon


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ADU Ordinance

Zones allowed

All single-family residential zones

Lot restrictions
Lot must be developed with a single-family residence
Minimum lot size

6,000 sf

Min / Max ADU size

Min: none
Max attached: not to exceed 50% of existing living area with max increase of 640 sf
Max detached: 640 sf
ADUs that comply with all aspects of the disabled access requirements for kitchens, bathrooms, and accessible routes have a max of 700 sf.

ADU building height

Same as primary dwelling but detached ADUs cannot exceed 17 feet


Attached: same as primary residence
Detached: same as primary residence except minimum rear setback is 10 ft; interior side and rear setbacks may be reduced to five feet, subject to written approval of the owner(s) of the contiguous property abutting the portion of the encroaching structure, or if the contiguous interior side or rear property line is an alley, or if the ADU is constructed above an existing detached garage

Parking requirements
One parking space is required unless state exemptions are met (ADU is within 1⁄2 mile of transit, built within an existing structure, in historic districts, within one block of car share locations, or in an area with residential parking permit rules that do not allow second units to get a permit) or existing ADU was permitted without additional parking. Parking in setbacks and tandem parking are allowed.
Owner occupancy

Owner must live in the main dwelling or the ADU unless nontenancy status is granted (see “Exceptions” below)


The exact amount of fees varies depending on the specifics of the proposal. In addition, there are various services provided by other districts, such as fire, sanitary, water, and schools that may assess a fee.

Other requirements

Building permit review is required. Making an appointment to meet with a planner in the initial stages of the project can help avoid challenges and is highly recommended.


If a property owner does not occupy the primary dwelling or the ADU, the property owner may apply for a nontenancy status for temporary job or school relocation or physical unability to live in the house.

Disclaimer: standards and process may vary. Consultation with the contact is recommended before starting any project.

Download ADU Standards PDF

Updated: 12/11/2017