Novato, CA Building Safety: Anti-Mansionization (2026)
Key Facts
- Applies to
- Parcels with average slope of 10 percent or greater
- Sliding scale
- Ratio falls one percent per one percent of slope
- Absolute cap
- 4,000 square feet regardless of ratio
- Garage and accessory allowance
- 500 square feet excluded from the ratio
- Table 3-6.1 at 30% slope
- 20% floor area ratio
- Review
- Design Review plus story poles
Summary
In the City of Novato, California, Municipal Code § 19.26.050.I limits new homes and additions on hillside lots by floor area ratio. The allowed ratio drops one percent for each percent of average slope, and no home can exceed 4,000 square feet. Division 19.26 applies to parcels with an average slope of 10 percent or greater.
I.Single-Family Residential Building Size Limits. A limitation on home size is required in hillside areas to ensure that the home is compatible with the hillside conditions and the scale of development in the community. Residential building sizes for new homes and additions to existing homes shall be limited by floor area ratio, utilizing a sliding-scale that is based on the average slope of the lot and the lot size. As the average slope of a lot increases by one percent, the allowable floor area ratio is decreased by one percent. The floor area ratio limits are presented in Tables 3-6.1 and 3-6.2. This resulting allowable floor area ratio represents a maximum limit subject to the following conditions and allowances:1.The maximum residential building size shall be limited to 4,000 square feet, regardless of the maximum permitted floor area ratio.2.A minimum single family residential building size of 2,000 square feet may be permitted, if deemed appropriate by the Review Authority.3.The allowable floor area ratio does not include a 500 square foot allowance for garage and accessory structures.
Full Breakdown
Novato does not leave house size on sloping lots to the setback and height tables alone. Section 19.26.050.I states that a limitation on home size is required in hillside areas so the home is compatible with hillside conditions and the scale of development in the community. Residential building sizes for new homes and additions are limited by floor area ratio on a sliding scale tied to the lot's average slope and the lot size. As the average slope rises by one percent, the allowable ratio falls by one percent.
Table 3-6.1 covers existing lots recorded on or before the enactment of Ordinance No. 1480, dated 1/13/04. It prints a maximum floor area ratio of 40% at a 10% average slope, 30% at 20%, 25% at 25%, 20% at 30% and 10% at 40% or more. Table 3-6.2, for lots recorded after that ordinance, runs only from 40% at 10% slope down to 25% at 25% slope, and Item 5 bars new residential lots where the average slope exceeds 25 percent.
Four conditions sit on top of the tables. The maximum residential building size is 4,000 square feet regardless of the ratio. A minimum building size of 2,000 square feet can be permitted if the Review Authority deems it appropriate. The ratio excludes a 500 square foot allowance for garage and accessory structures, and anything beyond 500 square feet counts against the ratio. An accessory dwelling unit counts against the primary residence's ratio too. Under Item 6, the Review Authority can consider a larger home where the property is secluded with minimal off-site visibility, or where the design is exemplary or unique in innovative architecture.
Process matters as much as the numbers. Section 19.26.030 requires Design Review for hillside development, except new accessory structures, additions under ten percent of the existing square footage, retaining walls and improvements the Director finds visually insignificant. Story poles must show the location, footprint, massing and height of the building. Flat lots follow the district tables instead: the R1-40, R1-20, R1-10, R1-7.5 and R4-6.0 rows of Section 19.10.050 print a 50% floor area ratio.
Violations & Fines
A home built larger than the Design Review approval and the Section 19.26.050.I ratio allows violates the Zoning Ordinance. Section 19.59.040 declares it unlawful and a public nuisance, makes the violator guilty of a misdemeanor or infraction at the City's election, and permits a Stop Work Order for construction that breaches permit conditions. Section 19.59.110 adds the Council's additional permit processing fees for work done without a required permit, and Section 19.59.090 adds a daily civil penalty under the Code Enforcement Fee Schedule.
Frequently Asked Questions
How large can a house be on a 30 percent slope in Novato?
Do garages and accessory dwelling units count toward the Novato size limit?
Can Novato approve a house bigger than the table allows?
Does the hillside size limit apply to a flat lot in Novato?
Sources & Official References
Other rules in Novato
California rules heatmap·Compare Novato to another location·View the California building safety overview
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