How San Ramon Handles Accessory Structures: A Practical Guide

San Ramon maintains 131 local ordinances across all categories, and 3 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where San Ramon falls on the strict-to-permissive spectrum compared to other cities.

Tiny Homes

San Ramon zoning treats a tiny house on wheels as a recreational vehicle, not housing, unless it sits on a permanent foundation. Municipal Code section D4-36.B caps a wheeled tiny house at under 320 square feet of interior living area and routes it into the RV storage limits of section D3-41.E.

Key details: Wheeled tiny house: Classified as an RV under 320 sq ft (D4-36.B). Foundation threshold: 150+ sq ft with kitchen/fridge becomes efficiency unit. Front setback storage: Prohibited for RVs/tiny houses (D3-41.E). Side yard storage: Allowed only behind a 7-foot screening fence. Driveway loading limit: 72 consecutive hours maximum.

A wheeled tiny house kept in a required front setback without qualifying under the closed 2006 grandfather registration is treated the same as any unauthorized recreational vehicle under D3-41.E and is subject to the City's standard zoning enforcement and abatement process. A tiny house built on a permanent foundation that does not meet the 150-square-foot efficiency-unit threshold, or that lacks Accessory Dwelling Unit approval under D4-39, is not a legal dwelling and cannot be occupied as one.

This is one of the stricter rules in San Ramon's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

ADU Rules

San Ramon allows accessory dwelling units and junior ADUs by right in every zone that permits residential use, including mixed-use districts, under Zoning Ordinance Section D4-39. Before a building permit issues, the owner must obtain a ministerial Zoning Clearance under Section D6-30; the city cannot deny a compliant ADU through discretionary review, per Ordinance No. 522.

Key details: Governing section: Zoning Ordinance Section D4-39. Review type: Ministerial Zoning Clearance, no hearing. Permit step: Zoning Clearance under Section D6-30 first. Adopted by: Ordinance No. 522, Section 6, 12/12/2023. Effective date: January 11, 2024.

Building without the required Zoning Clearance is a zoning violation enforceable under Title B of the Municipal Code, the same enforcement title that governs short-term rental and other zoning infractions citywide; the Building Division will not finalize permits on an ADU that skipped the D6-30 clearance step. Because review is ministerial, the more common dispute is a rejected application citing a state-law standard (size, height, parking) rather than a discretionary denial, which can be appealed through the Community Development Department.

The rules around adu rules in San Ramon lean permissive, but that does not mean anything goes.

Shed & Carport Rules

San Ramon caps backyard sheds and other accessory structures in residential zones at three percent of the lot's total floor area and enforces a sliding setback: no setback for structures 18 inches or less, a three-foot setback up to six feet in height, and setback equal to height minus three feet above that, under Zoning Ordinance Section D4-26.

Key details: Governing section: Zoning Ordinance Section D4-26. Max floor area (R zones): 3% of lot area. Height limit: 12 ft (HR/RS/RM) or 16 ft (RC/RE-A/RR). Setback under 18 in.: No setback required. Setback 18 in. to 6 ft: 3-foot setback required.

An accessory structure built over the three-percent floor-area cap, taller than the Table 4-2 limit, or sited inside a required setback is a zoning violation processed under the Municipal Code's general enforcement title; the Building and Community Development Departments can require the structure be modified, relocated or removed before any related building permit is finalized. Because the setback and height rules are objective numeric standards rather than discretionary findings, an out-of-compliance shed is typically resolved through a code-compliance case rather than a Use Permit hearing.

The Bottom Line

San Ramon's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming San Ramon is broadly strict or permissive.

Keep in mind that San Ramon can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.