Redwood City's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Redwood City, California, there are 4 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Garage Conversions

Garage conversions to ADUs are fully permitted in Redwood City per California ADU law. No replacement parking is required. Building permit is required. Conversion ADUs generally have no parking requirements.

Key details: Permitted: Yes, per CA ADU law. Building Permit: Required. Replacement Parking: Not required (state law). Contact: planning@redwoodcity.org | (650) 780-7236.

Unpermitted conversion: standard building code enforcement. Must bring to code or restore to garage. Safety violations: immediate correction.

Carport Rules

Redwood City Zoning Code Articles 5 (R-1 / RH), 6 (R-2), and 36 (Exterior Site Improvements) treat a carport as an accessory building. In R-1 and R-2 districts, a carport entrance or garage door must sit at least 20 feet behind the front property line, and the carport itself must meet the main building's interior side-yard setback and at least a 6-foot rear-yard setback under Section 36.5. Total accessory-building height is capped at 14 feet (with a 9-foot wall height adjacent to side and rear lines), and a building permit is required for any permanent posts and roof. Hillside parking may be located as close as 5 feet to the street property line at the Director's discretion.

Key details: Front Setback (R-1, RH, R-2): 20 ft for garage/carport entrance. Rear-Yard Setback: 6 ft minimum (Section 36.5). Side-Yard Setback: Match main building's side yard. Distance to Other Buildings: 6 ft minimum on same lot. Maximum Height: 14 ft total / 9 ft wall at side & rear.

Erecting a carport without a building permit, or one that intrudes into the 20-foot front setback, the 6-foot rear setback, or the 14-foot height limit, can result in a Code Enforcement Notice of Violation, a stop-work order, and an order to remove or modify the structure. Carports that exceed lot-coverage limits or block required parking are independently subject to zoning enforcement under Article 36. Daily fines for ongoing zoning violations follow the City's Master Fee Schedule and the Municipal Code's administrative-citation provisions. Unpermitted carports also create issues at resale and can block future permits — additions, ADUs, or kitchen/bath remodels — until the structure is brought into compliance or removed.

ADU Rules

Redwood City allows ADUs in all residential zones. One-bedroom ADUs up to 850 sq ft; two+ bedrooms up to 1,000 sq ft. Detached height limit is 24 ft. 4-ft rear/side setbacks. ADUs cannot be STRs (except pre-2020 registrations).

Key details: Max Size (1 BR): 850 sq ft. Max Size (2+ BR): 1,000 sq ft. Detached Height: 24 ft max (20 ft plate + 4 ft roof). Setbacks: 4 ft rear and interior sides. STR Restriction: No STRs except pre-2020 registrations.

Unpermitted ADU construction subject to code enforcement and fines.

Shed Rules

Small accessory structures (sheds) in Redwood City must comply with zoning setbacks and height limits. Sheds under 120 sq ft generally do not require a building permit but must still comply with zoning requirements.

Key details: Small Sheds: Under 120 sq ft usually no building permit. Setbacks: 4 ft from rear and side property lines. Habitable Use: Requires ADU permit. Contact: Building Division (650) 780-7350.

Unpermitted structure: retroactive permit with penalty. Non-compliant setback: modification or removal. Habitation violation: immediate correction.

The Bottom Line

Redwood City'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 Redwood City is broadly strict or permissive.

This guide is based on Redwood City's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.