Mill Valley · Building on your lot
Building on your lot in Mill Valley
Mill Valley sets its own fence permit limits, accessory-structure limits and home-business rules. Fence limits depend on whether the fence sits in an exterior or interior yard setback.
Key points
- Fence height: City rule: without a permit, fences are limited to 7 ft in interior setbacks or outside setbacks, 4 ft in exterior yard setbacks.
- Accessory structures: City rule: accessory structures are limited to 15 ft, 500 sq ft each, and 3 per lot, not counting pools and required garages.
- Home businesses: City rule: home businesses in residential districts need a business license and may employ no one except for domestic purposes.
Each rule below is marked Mill Valley code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.
Fences and walls
Mill Valley code City rule: without a permit, fences are limited to 7 ft in interior setbacks or outside setbacks, 4 ft in exterior yard setbacks.
All 3 Mill Valley rules on fences and walls, with the code text →
Sheds, garages and other accessory structures
Mill Valley code City rule: accessory structures are limited to 15 ft, 500 sq ft each, and 3 per lot, not counting pools and required garages.
All 6 Mill Valley rules on sheds, garages and other accessory structures, with the code text →
Running a business from home
| Employees |
|
|---|---|
| Permit |
|
| Businesses not allowed |
|
Lot splits under SB 9
Mill Valley code New lots must be about equal; neither may be smaller than 40% of the original lot area. Each new lot must be at least 1,200 square feet.
All 10 Mill Valley rules on lot splits under SB 9, with the code text →
RV and boat parking
| Parking on the street |
|
|---|
Solar panels and EV chargers
Mill Valley code Expedited nondiscretionary permit; complete applications meeting checklist and health and safety rules are approved administratively within 1 to 3 days. Expedited nondiscretionary permit, approved administratively when complete and meeting the checklist and all health and safety rules; no Design Review.
All 3 Mill Valley rules on solar panels and EV chargers, with the code text →
Tree removal
| Permit to remove |
|
|---|
Pets, chickens and bees
| Chickens |
|
|---|---|
| Coop setback |
|
| Large animals |
|
Building in a flood zone
Mill Valley code A development permit is needed before any construction or development, including manufactured homes, in a special flood hazard area. No encroachments, including fill, unless a registered engineer or architect shows no rise in flood elevation.
All 4 Mill Valley rules on building in a flood zone, with the code text →
Grading and erosion control
Mill Valley code A permit is needed to grade or fill more than 50 cubic yards. No permit if graded or filled volume at most 50 cubic yards, or natural and finished slopes are under 10%.
All 4 Mill Valley rules on grading and erosion control, with the code text →
Noise and construction hours
Mill Valley code 7:00 a.m. to 6:00 p.m. No construction on Saturday, Sunday or legal holidays without a special permit.
All 9 Mill Valley rules on noise and construction hours, with the code text →
Family child care homes
| Zoning | A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning |
|---|---|
| Business license or fee | A city or county may not charge a business license, fee or tax to run a family child care home |
| 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 |
| Small home | Up to eight children, counting the provider's own children under 10 who live there |
| Large home | 7 to 14 children, counting the provider's own children under 10 who live there |
Affordable units in new housing (inclusionary)
Mill Valley code Exempt: renovations and additions to existing homes costing less than the construction valuation threshold. Exempt: accessory dwelling units.
All 9 Mill Valley rules on affordable units in new housing (inclusionary), with the code text →
Parking spaces required for homes
| Garage and covered spaces |
|
|---|
Home alarm permits and false alarms
| How long an alarm may sound |
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|---|
Trash and recycling carts
Mill Valley code You must subscribe to solid waste collection service. You are not required to subscribe.
All 6 Mill Valley rules on trash and recycling carts, with the code text →
Who this affects
Frequently asked questions
Can I run a business from my home in Mill Valley?
City rule: home businesses in residential districts need a business license and may employ no one except for domestic purposes.
Do I need a permit to remove a tree in Mill Valley?
Mill Valley's code: The Director of Building and Planning may issue an emergency removal permit; the tree must be removed within 7 days. (A heritage tree that poses an immediate threat to people or property.) (§ 20.67.080).
Can I keep chickens or bees at my home in Mill Valley?
Mill Valley's code: At most 12 mature poultry; no crowing roosters, quacking ducks, geese, guinea fowl or peafowl. (Any premises in the city.) (§ 6.12.120); At least 40 feet. (Rabbits or poultry, from any dwelling on an adjacent property.) (§ 6.12.120).
Can I run a family child care home in Mill Valley?
California law sets this for every city, including Mill Valley: 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 Mill Valley?
Mill Valley's code: Parking spaces may be uncovered. (All zoning districts.) (§ 20.61.050).
Do I need a permit for a home alarm in Mill Valley?
Mill Valley's code: The alarm must shut off within 15 minutes. (§ 5.34.030); On U.L. certificated systems, the alarm must shut off within 30 minutes. (§ 5.34.030).
General information, not legal advice.
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