Building on a hillside in San Rafael: the local rules

Each rule below links to the section of the San Rafael Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What San Rafael's code says

San Rafael code What San Rafael's code adds
Soils or geology report	A geotechnical investigation is required before tentative map approval. Applies: Subdivisions in hillside areas with slopes over 25%. § 15.07.020 · code text A geotechnical investigation prepared consistent with the geotechnical review matrix shall be conducted.
Grading and retaining walls	New streets and driveways may be no steeper than 18%. Applies: Hillside development overlay district, unless the hearing body grants an exception. § 14.12.030 · code text New street and driveway grades shall not exceed eighteen percent (18%) unless an exception has been granted by the hearing body Driveways or streets may be as steep as 25%. Applies: Hillside overlay exception: needs hearing-body approval and a recommendation from the public works director and fire marshal. § 14.12.030 · code text the design has been recommended by the public works director and fire marshal to allow a driveway or street slope up to a maximum twenty-five percent (25%) grade.
Height on hillside lots	Walls may rise at most 20 feet from existing ground, then step back at least 5 feet. Applies: Downhill slopes in the hillside overlay district; the zoning district height limit still applies. § 14.12.030 · code text On any downhill slope a twenty-foot (20′) height limit measured from existing grade shall be observed. Walls may be at most 20 feet high from existing ground. Applies: Non-downhill slopes in the hillside overlay: walls facing front and side lot lines within 15 feet of the building envelope limit. § 14.12.030 · code text On non-downhill slope, walls facing front and side property lines shall have a twenty-foot (20′) height limit measured from existing grade shall be observed within all areas within fifteen feet (15′) of the maximum building envelope limit.
When hillside rules apply	Hillside rules apply to lots with an average slope of 25% or greater. Also lots in the hillside resource residential or hillside residential land use designations. § 14.12.020 · code text These regulations shall apply to all lots with an average slope of twenty-five percent (25%) or greater, or located in the hillside resource residential or hillside residential general plan land use designations. Hillside standards apply on lots with an average slope over 25%. Applies: New homes, accessory buildings, additions over 500 square feet, and roofline raises. § 14.16.200 · code text On new residential structures, accessory structures, additions over five hundred (500) square feet in size and any modification that increases the height of the roofline on such structures which are located on lots with an average slope greater than twenty-five percent (25%) or which are in the hillside resource residential or hillside residential general plan land use districts, the standards of Chapter 14.12, Hillside Development Overlay District, apply. Hillside lot design standards apply where slopes are over 25%. Applies: Subdivision applications; not SB 9 housing projects or urban lot splits. § 15.07.020 · code text The standards listed below shall be utilized to evaluate the lot configuration of all applications proposed in hillside areas where slopes are over twenty-five percent (25%).

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

San Rafael's code: Hillside rules apply to lots with an average slope of 25% or greater. (Also lots in the hillside resource residential or hillside residential land use designations.) (§ 14.12.020); New streets and driveways may be no steeper than 18%. (Hillside development overlay district, unless the hearing body grants an exception.) (§ 14.12.030).

Building on a hillside in San Rafael

What San Rafael's code says

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