Millbrae · Building on your lot

Building on your lot in Millbrae

Millbrae sets its own fence heights, accessory-building limits and home-business rules. Fence limits depend on the yard and on whether it faces a street or alley.

Ask about building on your lot in Millbrae See coverage

Key points

Fence height: Millbrae limits fences to 2.5 ft in required front yards and 6 ft in side and rear yards not on a street or alley.
Accessory buildings: City rule: accessory buildings in R districts are limited to 12 ft and must stand 5 ft from property lines and alleys.
Home businesses: City rule: home businesses need a home occupation permit and a city business license; on-site employees must live in the home.

Each rule below is marked Millbrae code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.

Fences and walls

Millbrae code What Millbrae's code adds
Corner visibility	No higher than 2.5 feet. Applies: Within the corner setback area. § 10.05.2010 · code text Within the corner setback area (d) \| 2.5' No higher than 2.5 feet. Applies: In the exterior yard on the rear 30 feet of a corner lot next to a side-fronting lot. § 10.05.2010 · code text Within exterior yard on the rear 30 feet of a corner lot which abuts a side fronting lot (e) \| 2.5' (c)
Height anywhere on the lot	No higher than 8 feet. Applies: Fences outside required yards that do not face a street or alley. § 10.05.2010 · code text – All others \| 8.0' (c) No higher than 6 feet. Applies: Fences outside required yards that face a street or alley. § 10.05.2010 · code text – Facing any street or alley \| 6.0' (c)
Front yard height	No higher than 2.5 feet. Applies: Within required front yards. § 10.05.2010 · code text Within required front yards (a) \| 2.5' (c)
Side and rear yard height	No higher than 2.5 feet. Applies: Within required side and rear yards next to a street or alley. § 10.05.2010 · code text Within required side and rear yards abutting a street or alley (a) \| 2.5' (c) No higher than 6 feet. Applies: Within required side and rear yards not next to a street or alley. § 10.05.2010 · code text Within required side and rear yard not abutting a street or alley \| 6.0' (c)
Permit	Yes. An encroachment permit is required. Applies: Any fence over, or within 3 feet of, a utility or public utility easement. § 10.05.2010 · code text Any fence over, or within three feet of, any utility or public utility easement unless an encroachment permit is first obtained.

Sheds, garages and other accessory structures

Millbrae code What Millbrae's code adds
Maximum height	No more than 12 feet high. Applies: Accessory buildings in residential districts. § 10.05.2000 · code text The maximum height of an accessory building shall be twelve feet.
Side and rear setback	At least 5 feet from any property line or alley. Applies: Accessory buildings in residential districts. § 10.05.2000 · code text Accessory buildings shall not be located within five feet of any property line of the lot or any alley.
Distance from the house	At least 10 feet from any home on the same lot or an abutting lot. Applies: Detached accessory buildings in residential districts; includes homes under construction. § 10.05.2000 · code text Detached accessory buildings shall be located at least ten feet from any dwelling existing or under construction on the same lot, or any abutting lot.

Running a business from home

Millbrae code What Millbrae's code adds
Customer visits	No customers may come to the home. § 10.05.1910 · code text No customers shall come to the dwelling. Only 1 customer at a time. Applies: Educational, instructional or consultation activity, by appointment only. § 10.05.1910 · code text The only exception shall be for an educational, instructional, or consultation activity which is by appointment only and involves no more than one customer at a time;
Employees	Employees who work at the home must live there as their primary residence; others must work off site. § 10.05.1910 · code text The dwelling unit must be the primary residence of the owner of the home-based business, as well as for all employees who work at the dwelling unit, while all other employees, if any, must work off site;
Permit	A home occupation permit and a City of Millbrae business license. § 10.05.1910 · code text No home occupation permit shall be issued without the applicant possessing or simultaneously applying for a city of Millbrae business license.
Businesses not allowed	barbershop, beauty salon, massage business, automobile repairing, painting or detailing, medical clinic, dog kennel or other boarding of pets, dog training, recording studio, and similar activities demonstrating the specified impacts Applies: Office use at home may be allowed when the service is done entirely off site (mobile pet grooming, mobile dent repair, mobile windshield repair, outcall massage) § 10.05.1910 · code text Barbershop, beauty salon, massage business, automobile repairing, painting or detailing, medical clinic, dog kennel or other boarding of pets, dog training, recording studio, and other activities considered to be of similar character by the community development director or designee that demonstrate any of the aforementioned impacts; however, certain businesses may be permitted to use the home for office purposes when the service is performed exclusively off site, such as mobile pet grooming, mobile automotive dent repair, mobile windshield repair, and outcall massage. home-based businesses involving hazardous materials or chemicals Applies: except very small production businesses such as jewelry making, gift basket arranging, or needlework § 10.05.1910 · code text Home-based businesses that involve hazardous materials or chemicals, with the exception of very small production businesses such as jewelry making, gift basket arranging, or needlework;

Lot splits under SB 9

Millbrae code Neither parcel may be smaller than 40% of the original lot area. Each unit may be no larger than 800 square feet.

All 23 Millbrae rules on lot splits under sb 9, with the code text and the state law underneath →

Solar panels and EV chargers

Millbrae code What Millbrae's code adds
EV charger permit	Administrative review; ministerial approval when the checklist, standards and requirements are met with no specific adverse impacts. § 9.20.060 · code text the City will approve the permit ministerially. Electronic submittal is allowed. § 9.20.050 · code text Permit application and other required documents may be submitted electronically to the City
Solar permit process	Administrative, nondiscretionary review; same-day permit over the counter for complete applications meeting the checklist and standard plan; only one inspection. Applies: Small residential rooftop solar systems. § 9.15.060 · code text The City will issue a building permit or other nondiscretionary permit the same day for over-the-counter applications Electronic submittal and electronic signatures are accepted. § 9.15.050 · code text Electronic submittal of the required permit application and documents will be made available to all small residential rooftop solar energy system permit applicants.
Review time	1 to 3 business days. Applies: Complete electronic applications meeting the approved checklist and standard plan. § 9.15.060 · code text or within one to three business days for electronic applications of receipt of a complete application that meets the requirements of the approved checklist and standard plan.

Tree removal

Millbrae code Routine trimming to keep a protected tree healthy needs no permit. The Planning Commission may allow another replacement measure instead of the in-lieu fee.

All 12 Millbrae rules on tree removal, with the code text and the state law underneath →

Other Millbrae rules on this

Millbrae's code also has these chapters. We have not summarized their values on this page yet; read them in the library.

Permit to keep more dogs and cats (§ 6.14.030)
Sleeping in an RV or camper on the street (§ 5.35.020) — on public streets at night
Permit to drain a pool to the sewer (§ 8.20.340)

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How tall can a fence be in Millbrae?

Millbrae limits fences to 2.5 ft in required front yards and 6 ft in side and rear yards not on a street or alley.

How big can a shed or accessory building be in Millbrae?

City rule: accessory buildings in R districts are limited to 12 ft and must stand 5 ft from property lines and alleys.

Can I run a business from my home in Millbrae?

City rule: home businesses need a home occupation permit and a city business license; on-site employees must live in the home.

Do I need a permit for solar panels or an EV charger in Millbrae?

Millbrae's code: Administrative review; ministerial approval when the checklist, standards and requirements are met with no specific adverse impacts. (§ 9.20.060); Electronic submittal is allowed. (§ 9.20.050).

General information, not legal advice.

Ask about a specific Millbrae property

Ask GoCodebook how these rules apply to your address and get an answer that cites the section.

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More on Millbrae

Millbrae Municipal Code — full text

Renting & eviction in Millbrae

Buying & selling in Millbrae

Millbrae overview