Hillsborough · Building on your lot

Building on your lot in Hillsborough

Hillsborough sets its own limits for fences and hedges near streets and for the size of covered accessory structures. Hedge limits apply along streets, not only at corners.

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Key points

Fences and hedges: Hillsborough limits fences in the right-of-way or a street-side setback to 8 ft; hedges within 25 ft of the street center line, 4 ft.
Accessory structures: Hillsborough limits each covered accessory structure to 1,000 sq ft of floor area, with no limit on the number of structures.

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

Fences and walls

Hillsborough code What Hillsborough's code adds
Height anywhere on the lot	Hedges may be no higher than 4 feet. Applies: Hedges within 25 feet of the street center line. Hedges over 4 feet in December 1998 may stay until cut below 4 feet. § 12.08.010 · code text no hedge shall be maintained at a height greater than four feet if the hedge is twenty-five feet or less from the center line of the street 8 feet, measured from finished grade at the fence base to its highest point, on either side. Applies: For fences in the right-of-way or in a setback area next to a public street. § 12.12.050 · code text the vertical distance of any fence measured from finished grade at the base of the fence to the highest point of the fence shall be eight feet on either side of the fence.

Sheds, garages and other accessory structures

Hillsborough code What Hillsborough's code adds
Size or lot coverage	No more than 1,000 square feet of floor area for each covered accessory structure. Applies: There is no limit on the number of accessory structures on a lot. Some exceptions to the size limit apply. § 17.32.050 · code text There is no limitation on the number of accessory structures that may be allowed on a lot; provided, however, that each covered accessory structure shall not exceed one thousand square feet in floor area, except as otherwise set forth in Sections 17.52.020(C)(5) and (C)(6).

Lot splits under SB 9

Hillsborough code What Hillsborough's code adds
How the lot may be divided	Each new lot must be between 40% and 60% of the original lot area. Applies: Applies to urban lot splits (SB 9). § 16.44.050 · code text Each of the resulting lots must be between sixty percent and forty percent of the original lot area.
Minimum new lot size	Each new lot must be at least 1,200 square feet. Applies: Applies to urban lot splits; the lot being split must be at least 2,400 square feet. § 16.44.050 · code text The resulting lots must each be at least one thousand two hundred square feet.
Standards	The lot being split must be in a single-family residential zone. Applies: Applies to urban lot splits (SB 9). § 16.44.050 · code text The lot to be split is in a single-family residential zone. Each new lot must border the public right-of-way with at least 50 feet of frontage. Applies: Applies to each lot created by an urban lot split. § 16.44.050 · code text Each resulting lot must have frontage on the public right of way of at least fifty feet. No more than 2 dwelling units of any kind, including ADUs and JADUs, per new lot. Applies: Applies to each lot created by an urban lot split. § 16.44.050 · code text No more than two dwelling units of any kind may be built on a

Solar panels and EV chargers

Hillsborough code What Hillsborough's code adds
Solar permit process	Administrative, nondiscretionary review; only one inspection, done within 3 business days. Applies: Applies to small rooftop solar systems eligible for expedited review. § 15.37.040 · code text The building and planning department shall provide an administrative, nondiscretionary review process to expedite approval of the small rooftop systems. Architecture and Design Review Board approval first, then a building permit. Applies: Applies to any solar panel. § 15.36.010 · code text any solar panel (the above items (1) through (4) collectively referred to as "Towers" in the plural and "Tower" in the singular) shall first obtain approval of the Architecture and Design Review Board under Title 2 and next obtain a building permit as provided in this chapter.

Tree removal

Hillsborough code A permit may be issued if a certified arborist writes that disease, damage or danger requires removal within 30 days. A misdemeanor.

All 8 Hillsborough rules on tree removal, with the code text →

Swimming pools

Hillsborough code What Hillsborough's code adds
Pool barrier	Every pool, hot tub and spa needs barriers against unauthorized entry, of the type the state building code describes. Applies: Applies to pools, hot tubs and spas built after September 7, 1993; design review approval if applicable. § 15.56.010 · code text Such barriers shall be of the type described in, and otherwise comply with the provisions of, Appendix Chapter 4 of the California Uniform Building Code, 2001 Edition, or successor provision,

Pets, chickens and bees

Hillsborough code Allowed: no more than 3 hives per residential property, and no more than 3 in town per owner. Fowl must be kept in an escape-proof enclosure; the number is not stated.

All 3 Hillsborough rules on pets, chickens and bees, with the code text →

Grading and erosion control

Hillsborough code What Hillsborough's code adds
When a grading permit is needed	A grading permit is needed for 50 cubic yards or more, counting material removed and added together. Applies: Moving more than 1,500 cubic yards to or from the site also needs city council approval. § 15.24.030 · code text Grading of fifty or more cubic yards of material, with a maximum of one thousand five hundred cubic yards to be taken from the site to an off-site location and/or from an off-site location to the site, shall require a grading permit
Grading without a permit	No grading permit for under 50 cubic yards of material. Applies: This minor grading is approved with the building permit. § 15.24.030 · code text Grading under fifty cubic yards of material shall require no grading permit; such minor grading shall be considered approved along with the granting of a building permit.

Building on a hillside

Hillsborough code What Hillsborough's code adds
When hillside rules apply	The hillside chapter applies to land with an average slope of 10% or more. § 16.12.010 · code text The intent of this chapter is to regulate land in hillside areas with an average slope of ten percent or greater in order to accomplish one or more of the following:

Family child care homes

CA state law California law
Zoning	A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning Health & Safety Code § 1597.45(a)
Business license or fee	A city or county may not charge a business license, fee or tax to run a family child care home Health & Safety Code § 1597.45(b)
Local rules	Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone Health & Safety Code § 1597.45(e)
Small home	Up to eight children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(c)
Large home	7 to 14 children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(b)

Parking spaces required for homes

Hillsborough code Existing garages may not be removed or converted unless another compliant garage is built to replace them. Required garage spaces must be usable independently of each other.

All 5 Hillsborough rules on parking spaces required for homes, with the code text →

Signs on homes

Hillsborough code 1 sign per property, no larger than 12 inches by 15 inches. May be posted once the owner decides to offer the property for sale, rent or lease.

All 3 Hillsborough rules on signs on homes, with the code text →

Trash and recycling carts

Hillsborough code What Hillsborough's code adds
Where carts are kept	On the property being served. § 8.12.020 · code text All garbage and solid waste shall be kept in suitable containers located on the property being served and ready for collection and disposal by persons, firms or agencies willing and able to provide this service.

Other Hillsborough rules on this

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

Building in a flood hazard area (Ch. 15.44)
Garage and estate sales (Ch. 17.44)
Noise rules (Ch. 8.32)

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How tall can a fence be in Hillsborough?

Hillsborough limits fences in the right-of-way or a street-side setback to 8 ft; hedges within 25 ft of the street center line, 4 ft.

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

Hillsborough limits each covered accessory structure to 1,000 sq ft of floor area, with no limit on the number of structures.

Can I split my lot under SB 9 in Hillsborough?

Hillsborough's code: Each new lot must be at least 1,200 square feet. (Applies to urban lot splits; the lot being split must be at least 2,400 square feet.) (§ 16.44.050); The lot being split must be in a single-family residential zone. (Applies to urban lot splits (SB 9).) (§ 16.44.050).

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

Hillsborough's code: Administrative, nondiscretionary review; only one inspection, done within 3 business days. (Applies to small rooftop solar systems eligible for expedited review.) (§ 15.37.040); Architecture and Design Review Board approval first, then a building permit. (Applies to any solar panel.) (§ 15.36.010).

What are the pool fence and setback rules in Hillsborough?

Hillsborough's code: Every pool, hot tub and spa needs barriers against unauthorized entry, of the type the state building code describes. (Applies to pools, hot tubs and spas built after September 7, 1993; design review approval if applicable.) (§ 15.56.010).

What are the grading rules in Hillsborough?

Hillsborough's code: A grading permit is needed for 50 cubic yards or more, counting material removed and added together. (Moving more than 1,500 cubic yards to or from the site also needs city council approval.) (§ 15.24.030); No grading permit for under 50 cubic yards of material. (This minor grading is approved with the building permit.) (§ 15.24.030).

What extra rules apply to a hillside lot in Hillsborough?

Hillsborough's code: The hillside chapter applies to land with an average slope of 10% or more. (§ 16.12.010).

Can I run a family child care home in Hillsborough?

California law sets this for every city, including Hillsborough: Zoning: A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning (Health & Safety Code § 1597.45(a)); Business license or fee: A city or county may not charge a business license, fee or tax to run a family child care home (Health & Safety Code § 1597.45(b)); Local rules: Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone (Health & Safety Code § 1597.45(e)); Small home: Up to eight children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(c)); Large home: 7 to 14 children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(b)).

When can trash carts go out to the curb in Hillsborough?

Hillsborough's code: On the property being served. (§ 8.12.020).

General information, not legal advice.

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