Colma Accessory Dwelling Unit (ADU) Standards

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


Colma Planning Department - 650.757.8888

ADU Ordinance



Zones allowed

R, G (caretaker units), C (single family residences only), and RS (within existing footprint only)

Lot restrictions


Minimum lot size
Min / Max ADU size

None / 800 sf

ADU building height

Attached: 27 feet (same as primary dwelling)

Detached: 12 feet (discretionary after 6 feet)


Same as primary dwelling

Parking requirements

One space is required unless state exemptions are met (ADU is within 1⁄2 mile of transit, in existing structures, 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). Tandem parking and parking in setbacks are allowed.

Owner occupancy

Owner must live in the main dwelling or the ADU

Sample fees from recently built projects*

ADU 1 (800 sq ft, detached): $5,692
ADU 2 (500 sq ft, garage conversion): $1,740

(sample fees do not include water and sewer fees)

Other requirements
  • Only one ADU per property is allowed.
  • ADUs are not allowed on lots with multifamily dwellings.
  • ADUs must comply with all requirements of the underlying zoning district.

A staff level administrative use permit is required. Design standards must meet basic standards in the code. Making an appointment to meet with a planner in the initial stages of the project can help avoid challenges and is highly recommended.



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

Download ADU Standards PDF

Updated: 12/29/2017