San Anselmo · Building on your lot

Building on your lot in San Anselmo

San Anselmo sets its own rules for keeping hens, pool barriers, trailer storage, rooftop solar permits and SB 9 lot splits. Hens need a residential chicken-keeping permit and must be kept away from neighboring residences.

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Key points

Hens: Keeping hens needs a town permit: at most 6 hens, or up to 12 with written consent of all adjacent owners or special circumstances.
Pool barriers: Pool barriers must be at least 5 feet tall; a barrier or compliant pool cover must be in place before any water is added.
SB 9 splits: SB 9 splits in R-1 zones make 2 near-equal parcels, each at least 1,200 square feet and 40% of the original parcel.
Trailer storage: Trailers and camp cars kept on the owner's property must be screened from the street and neighbors, within permitted height limits.
Rooftop solar: Complete rooftop solar applications are processed the same day over the counter or in 1 to 3 business days electronically.

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

Lot splits under SB 9

San Anselmo code SB 9 splits in R-1 zones make 2 near-equal parcels, each at least 1,200 square feet and 40% of the original parcel.

All 6 San Anselmo rules on lot splits under SB 9, with the code text →

RV and boat parking

San Anselmo code Trailers and camp cars kept on the owner's property must be screened from the street and neighbors, within permitted height limits.

All 4 San Anselmo rules on RV and boat parking, with the code text →

Solar panels and EV chargers

San Anselmo code Complete rooftop solar applications are processed the same day over the counter or in 1 to 3 business days electronically.

All 4 San Anselmo rules on solar panels and EV chargers, with the code text →

Swimming pools

San Anselmo code What San Anselmo's code adds
Pool barrier	A barrier at least 5 feet tall meeting building code, or an ASTM F1346 pool cover, must be in place. Applies: Before any water goes in the pool, including for curing the pool walls. § 9-1.203 · code text Before water is placed in a pool for any reason, including the curing of the pool walls, a barrier at least 5' tall conforming to the requirements of CBC Section 3109 must be in place or a pool cover complying with ASTM F1346 must be installed and operational.
Barrier height	At least 5 feet tall. Applies: Applies to barriers around a swimming pool. § 9-1.203 · code text Barriers enclosing a swimming pool must be at least 5' tall.

Pets, chickens and bees

San Anselmo code Keeping hens needs a town permit: at most 6 hens, or up to 12 with written consent of all adjacent owners or special circumstances.

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

Building in a flood zone

San Anselmo code What San Anselmo's code adds
Floodplain permit	A permit is needed before any construction or other development, including manufactured homes, in a special flood hazard area. § 7-11.403 · code text A development permit shall be obtained before any construction or other development, including manufactured homes, within any area of special flood hazard established in Section 3.2.
Building in a floodway	No fill, new building, substantial improvement or other development unless a civil engineer certifies no rise in flood levels. Applies: Inside an adopted regulatory floodway. § 7-11.506 · code text Within an adopted regulatory floodway, the Town of San Anselmo shall prohibit encroachments, including fill, new construction, substantial improvements, and other development, unless certification by a registered civil engineer is provided demonstrating that the proposed encroachment shall not result in any increase in flood levels during the occurrence of the base flood discharge. No new building or development, including fill, unless all development combined raises base flood level no more than 1 foot. Applies: Zones A1-30 and AE, until a regulatory floodway is adopted; measured at any point in the Town. § 7-11.506 · code text Until a regulatory floodway is adopted, no new construction, substantial development, or other development (including fill) shall be permitted within Zones A1—30 and AE, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other development, will not increase the water surface elevation of the base flood more than one (1) foot at any point within the Town of San Anselmo.
Height of the lowest floor	The lowest floor must be 1.00 feet above the base flood elevation. Applies: New or substantially improved homes in AE, AH and A1-30 zones; elevations in NAVD88. § 7-11.501 · code text In AE, AH, A1-30 Zones, elevated to 1.00 feet above the base flood elevation pursuant to NAVD88. The lowest floor must be 1 foot above the base flood elevation. Applies: New or substantially improved homes in an unnumbered A zone with no base flood elevation on the FIRM; elevations in NAVD88. § 7-11.501 · code text In an A zone, without BFE's specified on the FIRM [unnumbered A zone], elevated to one (1) feet above the base flood elevation pursuant to NAVD88; as determined under Section 7-11.402(c). 1 foot above the FIRM depth number, measured from the highest nearby grade. Applies: New or substantially improved homes in an AO zone with a depth number on the FIRM. § 7-11.501 · code text In an AO zone, elevated above the highest adjacent grade to a height one (1) feet above the depth number specified in feet on the FIRM, or elevated at least two (2) feet above the highest adjacent grade if no depth number is specified pursuant to NAVD88. At least 2 feet above the highest nearby grade. Applies: New or substantially improved homes in an AO zone with no depth number on the FIRM. § 7-11.501 · code text In an AO zone, elevated above the highest adjacent grade to a height one (1) feet above the depth number specified in feet on the FIRM, or elevated at least two (2) feet above the highest adjacent grade if no depth number is specified pursuant to NAVD88.

Grading and erosion control

San Anselmo code Slopes of digging, fill or grading may be no steeper than 2:1. No permit when less than 25 cubic yards of earth or material is moved.

All 3 San Anselmo rules on grading and erosion control, with the code text →

Building on a hillside

San Anselmo code What San Anselmo's code adds
When hillside rules apply	R-1 lots with an average slope of 15% or more need a larger minimum lot area. Applies: R-1 District; see the slope density table (Table 4C). § 10-3.409 · code text The Slope Density/Lot Area Table, referred to as Table 4C, lists the minimum lot size for the R-1 District for lots which have average slopes of fifteen (15%) percent or greater.

Noise and construction hours

San Anselmo code 7:00 a.m. to 7:00 p.m., Monday through Friday. 9:00 a.m. to 5:00 p.m. on Saturdays.

All 6 San Anselmo rules on noise and construction hours, with the code text →

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

San Anselmo code What San Anselmo's code adds
Garage and covered spaces	A parking space at least 8 by 17 feet may not be converted to another use unless replaced Applies: Converting a garage, carport or uncovered parking space; the site must still have the required spaces § 10-3.504 · code text No parking space either uncovered or within a garage or carport, having minimum dimensions of eight (8) feet in width by seventeen (17) feet in depth, shall be converted to a use other than for vehicular parking, unless the following conditions are satisfied:

Signs on homes

San Anselmo code 2 square feet; 1 display face Number of sign faces not limited; at most 8 square feet per sign face

All 5 San Anselmo rules on signs on homes, with the code text →

Trash and recycling carts

San Anselmo code By 12:01 a.m. on the day following the scheduled pick-up Not before 12:01 a.m. on the day preceding the day of scheduled pick-up

All 3 San Anselmo rules on trash and recycling carts, with the code text →

Other San Anselmo rules on this

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

Permit to remove trees on private property (Title 4, Ch. 13)

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What are the pool fence and setback rules in San Anselmo?

Pool barriers must be at least 5 feet tall; a barrier or compliant pool cover must be in place before any water is added.

What are the rules for building in a San Anselmo flood zone?

San Anselmo's code: A permit is needed before any construction or other development, including manufactured homes, in a special flood hazard area. (§ 7-11.403); The lowest floor must be 1.00 feet above the base flood elevation. (New or substantially improved homes in AE, AH and A1-30 zones; elevations in NAVD88.) (§ 7-11.501).

What extra rules apply to a hillside lot in San Anselmo?

San Anselmo's code: R-1 lots with an average slope of 15% or more need a larger minimum lot area. (R-1 District; see the slope density table (Table 4C).) (§ 10-3.409).

Can I run a family child care home in San Anselmo?

California law sets this for every city, including San Anselmo: 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)).

How many parking spaces does a home need in San Anselmo?

San Anselmo's code: A parking space at least 8 by 17 feet may not be converted to another use unless replaced (Converting a garage, carport or uncovered parking space; the site must still have the required spaces) (§ 10-3.504).

General information, not legal advice.

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