City of Monte Sereno - Santa Clara ADU

Wondering if your community has pre-approved ADU plans? See more details here

Wondering if your community has pre-approved ADU plans? See more details here

A project of the Santa Clara County Planning Collaborative

Home > Local Rules > City of Monte Sereno

Local ADU Rules

City of Monte Sereno

Last Updated September 30, 2025

ADU Contact:

Phone: 408-354-7635 ext. 116

Email cityplanner@cityofmontesereno.org

General Information	Details
ADU resources	https://www.montesereno.org/DocumentCenter/View/3828/Accessory-Dwelling-Unit-Information
Pre-Approved Plans
Planning	https://www.montesereno.org/2152/Building-and-Planning-Departments
Building	https://www.montesereno.org/2152/Building-and-Planning-Departments
School District	Los Gatos Union School District https://www.lgusd.org/apps/pages/index.jsp?uREC_ID=222278&type=d&pREC_ID=497973
Utilities	PG&E https://www.pge.com/en_US/small-medium-business/building-and-property/building-and-maintenance/building-and-renovation.page Water: San Jose Water https://www.sjwater.com/ Sewer: West Valley Sanitation District http://www.westvalleysan.org/ Trash & Recycling: West Valley Collection & Recycling, LLC https://westvalleyrecycles.com/
County Departments	Santa Clara County Office of the Clerk-Recorder https://clerkrecorder.sccgov.org/home
ADU Ordinance	https://library.municode.com/ca/monte_sereno/codes/code_of_ordinances?nodeId=MUCO_TIT10PLZO_CH10.06GEPR_10.06.140ACDWUNJUACDWUNSTRE

Standards and Rules	Details
Process Overview	Only a building permit is required – no separate planning permit
Zones allowed	All single family (R-1-8, R-1-20, R-1-44) zones
Minimum ADU Size	No minimum
Maximum ADU Size	1,000 SF or 1,200 SF maximum depending on zoning district
Number of ADUs/Bedrooms	No restrictions
Maximum ADU Height	16 feet for one story If attached to the main house, can be the same height allowed for the main house, up to 30 feet
Setbacks	Detached ADU shall meet front yard setbacks (unless that would preclude an ADU), side and rear yard setbacks are 4 feet each, corner lot setback to meet the requirement of the zoning district Attached ADU shall meet the setbacks of the main house
Lot or Location Restrictions	Attached ADU shall meet the setbacks of the main house An ADU of up to 800 SF is allowed even if it will cause the lot to exceed the structural and impervious coverage limits
Parking Requirements	One covered or uncovered, unless within 1/2 mile of transit or as part of a new house main house
Other Requirements	JADUs are not considered a separate unit for building code purposes
Owner Occupancy	JADUs: Owner must occupy either the JADU or the primary house
Deed Restrictions	None
Renting Regulations	Generally, ADUs and JADUs cannot be rented for fewer than 30 days at a time
Departments and Agencies Involved in Permitting	In addition to the City of Monte Sereno, plans are reviewed by Santa Clara County Fire Department and West Valley Sanitation District
Fees for ADUs	City Council approved a 50% building permit and plan check fee discount for the first 225 property owners who provide a written intention to construct an ADU
Sample Fees From Recently Built Projects	In 2002, a new 850 SF detached ADU had building permit fees of approximately $6,400 In 2022, a new 1,200 SF detached ADU has building permit fees of approximately $11,500

Wondering what you can build?

Make sure you check out our Learning the Rules page for more step-by-step details