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 What Hillsborough's code adds
Permit to remove	A permit may be issued if a certified arborist writes that disease, damage or danger requires removal within 30 days. Applies: Applies to protected trees; a town-qualified arborist reviews the opinion. § 14.04.040 · code text the building and planning official, or designee, may issue a permit for the removal of a protected tree described in such subsection A if the owner or occupant of the real property on which the protected tree is located presents a written opinion from a certified arborist that, because of disease or damage or danger to persons or property, the protected tree needs to be removed within the next thirty days. Yes, a tree removal permit is required. Applies: Applies to all protected tree removals; reviewed by the architecture and design review board or staff. § 14.04.040 · code text All protected tree removals require review and approval from the building and planning department (by the architecture and design review board or administratively at the staff level). A tree removal permit must be obtained from the building and planning official, or designee. Yes, a protected tree removal permit is required. Applies: Applies to removing a protected tree in a subdivision. § 14.04.030 · code text Should a protected tree require removal in a subdivision, a protected tree removal permit must be submitted.
Penalty	A misdemeanor. Applies: Applies to damaging or destroying a tree in violation of the tree rules or a related agreement. § 14.04.060 · code text Any person who damages or destroys a tree, in violation of this chapter or any agreement entered into pursuant thereto, shall be guilty of a misdemeanor. $150 per inch of trunk diameter, or the tree's appraised value, whichever is greater. Applies: Applies when the tree was destroyed or cannot be restored to its former condition. § 14.04.060 · code text a penalty will be assessed of either one hundred fifty dollars per inch of trunk diameter of the removed tree, or the appraised value of the removed tree as determined by the most recent edition of the International Society of Arboriculture (ISA) Guide for Plan Appraisal, whichever is greater. An additional fee may be charged to offset damage caused during removal. Applies: Applies when the tree was destroyed or cannot be restored to its former condition. § 14.04.060 · code text An additional fee may be assessed to mitigate damages caused during the tree removal.
Replacement trees	A replacement tree of at least 36-inch box size, planted within 6 months. Applies: Applies when a tree was destroyed or cannot be restored, in violation of the tree rules. § 14.04.060 · code text In addition, a replacement tree will be required that is a minimum of thirty-six-inch box size of a species approved by the town, and that it be replaced within six months. The removal permit must state how many replacement trees will be planted and how they are maintained. Applies: Applies to protected tree removal permits. § 14.04.040 · code text A statement indicating the number of replacement trees to be replanted and associated maintenance.

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 What Hillsborough's code adds
Bees	Allowed: no more than 3 hives per residential property, and no more than 3 in town per owner. Applies: Each hive must be more than 50 feet from any street, home or public gathering place. § 6.24.010 · code text The total number of hives or swarms kept within the town by the owner of the bees does not exceed three, and no more than three hives or swarms are kept on any one residential property within the town ("residential property" meaning the legal parcel or contiguous legal parcels which together are used as the location for one residence).
Chickens	Fowl must be kept in an escape-proof enclosure; the number is not stated. Applies: Applies to all fowl kept in town. § 6.24.040 · code text All fowl permitted to be kept within the town shall be kept and confined within a yard, pen, corral, chicken or bird house, or other enclosure (all hereinafter referred to as "enclosure" or "enclosures") so constructed as to make escape impossible.
Coop setback	At least 125 feet from any home the resident does not own, lease or control. Applies: Applies to any part of a fowl enclosure. § 6.24.040 · code text No part of any enclosure shall be within one hundred twenty-five feet of any dwelling that is not owned, leased, or otherwise controlled by the resident of the property on which the enclosure is located.

Who this affects

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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 between 40% and 60% of the original lot area. (Applies to urban lot splits (SB 9).) (§ 16.44.050); 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).

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).

Do I need a permit to remove a tree in Hillsborough?

Hillsborough's code: A permit may be issued if a certified arborist writes that disease, damage or danger requires removal within 30 days. (Applies to protected trees; a town-qualified arborist reviews the opinion.) (§ 14.04.040); A misdemeanor. (Applies to damaging or destroying a tree in violation of the tree rules or a related agreement.) (§ 14.04.060).

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).

Can I keep chickens or bees at my home in Hillsborough?

Hillsborough's code: Allowed: no more than 3 hives per residential property, and no more than 3 in town per owner. (Each hive must be more than 50 feet from any street, home or public gathering place.) (§ 6.24.010); Fowl must be kept in an escape-proof enclosure; the number is not stated. (Applies to all fowl kept in town.) (§ 6.24.040).

General information, not legal advice.

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