Do I need a permit in Redwood City, CA?
Redwood City sits on the Peninsula between the Bay and the Santa Cruz Mountains, which means your permit rules depend partly on where your property sits. Coastal and mid-Peninsula properties fall under climate zone 3B–3C with minimal frost risk; foothills and mountain properties face zone 5B–6B with 12–30 inches of frost depth that affects deck footings and foundation work. The City of Redwood City Building Department handles all residential permits from single-family additions to major remodels. California's Business & Professions Code § 7044 allows owner-builders to pull permits and do their own work, but you'll need a licensed electrician and licensed plumber for any electrical work, plumbing, or gas work — you can't legally do those yourself even if you're the homeowner. Most residential permits file through the online portal, but plan-check review timelines and fee structures are consistent across the city. A 90-second call to the Building Department before you order materials or book a contractor can save weeks of rework.
What's specific to Redwood City permits
Redwood City adopts the California Building Code (currently the 2022 CBC, which incorporates the 2021 IBC with California amendments). If you're upgrading an older home, code cycles matter: the 2022 code is stricter on electrical egress, attic access, and insulation than the 2019 version, and significantly stricter than anything pre-2016. Plan-check reviewers will flag code mismatches between existing work and new additions, so budget time for corrections if your home was built before 2000.
Soil conditions vary sharply by location. Coastal properties and Bay Area foothills typically rest on bay mud or granitic soils with good bearing capacity but variable settlement characteristics. Plan-check reviewers will often ask for a soils engineer report on new foundations, especially if your property has fill or prior disturbance. Mountain properties face granitic soils and steeper slopes, which triggers slope stability and drainage reviews. Bring a survey and photo of the site when you file — reviewers use these to flag hidden issues early.
The frost-depth variation is real: coastal and mid-Peninsula properties need deck footings 12 inches below grade (well above the IRC minimum of 36 inches for non-frost zones); foothills and mountain properties jump to 18–30 inches depending on exact elevation. Get this wrong and your footing inspection fails. If your property is near the climate zone boundary (around 1,000–1,500 feet elevation), ask the Building Department to confirm your frost depth in writing before you dig.
Plan-check turnaround in Redwood City averages 2–3 weeks for straightforward projects (decks, room additions, electrical upgrades), but 4–6 weeks for projects requiring engineering review or environmental assessment. Complex remodels, additions on small lots, or work near sensitive areas (creeks, wetlands, tribal lands) can add another 2–4 weeks. File early in the week and avoid mid-month when the queue backs up.
The online portal requires an account and digital file uploads (PDFs, site plans, calculations). Over-the-counter permits (simple roof replacements, water-heater swaps, small electrical panels) are possible but less common than online filing. Bring or email a complete application package on the first try — incomplete submissions get returned, adding 3–5 days to the cycle.
Most common Redwood City permit projects
These projects show up in the Building Department's queue constantly. Click through to see local thresholds, fees, inspection points, and next steps specific to Redwood City.
Decks
Any deck over 200 square feet or over 30 inches above grade requires a permit in Redwood City. Frost depth is the hidden cost: foothills and mountain properties need footings bottomed at 18–30 inches, not the coastal standard of 12 inches. Plan for two inspections: framing and final.
Room additions
A bedroom, office, or family room addition requires permits for framing, mechanical, electrical, plumbing, and grading. Redwood City plan-check reviewers flag window egress (IRC R310 requires direct egress for bedrooms), lot coverage, setbacks, and drainage. Mountain properties often need slope stability review. Budget 4–6 weeks for plan check.
Kitchen and bathroom remodels
Permits required if you're moving walls, changing plumbing runs, upgrading electrical service, or adding/relocating receptacles in wet areas. Bathroom ventilation (IRC M1501) and kitchen ventilation (IBC 502) are always reviewed. Cosmetic-only work (new counters, cabinets, flooring) typically doesn't need a permit.
Electrical panel upgrades
Panel upgrades, sub-panels, and branch-circuit additions all require a permit and licensed electrician. Redwood City uses NEC 2023 (via the 2022 CBC). Main panel work is inspected before you close up walls. Expect a 1–2 week turnaround for straightforward panels; longer if load calculations or bonding issues arise.
Garage conversions
Converting a garage to living space is common but heavily reviewed: you'll need egress windows, sprinklers, fire separation, and an accessible parking space elsewhere on the property (per California Title 24). Electrical and plumbing upgrades are standard. Mountain properties often fail egress review due to grade or slope — budget extra time for design fixes.
Solar installation
Residential rooftop solar (residential photovoltaic systems under 10 kW) follows California's streamlined AB 2188 process. Redwood City issues permits over-the-counter with standard documentation. Battery storage adds complexity and plan-check time. Turnaround is typically 1–2 weeks if you use an approved installer; DIY applications face stricter review.
Redwood City Building Department
City of Redwood City Building Department
1017 Middlefield Road, Redwood City, CA 94063 (verify current location with city website)
650-780-7250 (confirm current number)
Monday–Friday, 8 AM–5 PM (verify before visiting)
Online permit portal →
California context for Redwood City permits
Redwood City operates under the California Building Code (2022 CBC), which is the state's adoption and amendment of the 2021 International Building Code. California adds stricter requirements in seismic design (Title 24 Part 2), Title 24 energy code (insulation, HVAC efficiency, lighting), and electrical (NEC 2023 with state amendments). You can pull permits as an owner-builder under Business & Professions Code § 7044, but all electrical work must be done by a California-licensed electrician (any voltage, any circuit), and all plumbing and gas work must be done by a licensed plumber. This is not optional — mixing unlicensed work into a permitted project can result in inspection failure, permit revocation, and liability issues if something fails. California Title 24 energy requirements apply to most renovations: if you're replacing more than 25% of roof, wall, window, or HVAC systems, the whole building's energy performance is reviewed. Plan accordingly.
Common questions
Can I pull a permit as the homeowner and do the work myself?
Yes, under California Business & Professions Code § 7044, but with critical limits. You can frame, add drywall, paint, install fixtures — essentially all non-licensed work. Electrical work (any voltage, any circuit) must be done by a California-licensed electrician. Plumbing and gas work must be done by a licensed plumber. If you hire a general contractor, that contractor must be C-10 licensed (general building) or hold a specific license for the trade. Mixing licensed and owner work is legal but must be documented on the permit application. Don't lie about who's doing the work — inspectors will catch it and your permit will be revoked.
How long does plan check take in Redwood City?
Typical turnaround is 2–3 weeks for straightforward projects (decks, electrical upgrades, water-heater swaps). Room additions and remodels with mechanical/electrical/plumbing work average 4–6 weeks. Complex projects requiring engineering review (slope analysis, soils report, structural design), environmental review, or tribal consultation can take 8–12 weeks. Submit a complete, well-organized application the first time — incomplete submissions get returned unreviewed, costing 3–5 days. If the reviewer asks for corrections or clarifications, turnaround on resubmittals is typically 1–2 weeks.
Do I need a separate electrical permit if I'm doing a kitchen remodel?
Yes. If your remodel involves any electrical work — moving outlets, upgrading circuits, adding lighting, installing ventilation — you file a separate electrical permit (or your electrician does). Redwood City issues electrical permits over-the-counter same-day if the application is complete. The electrician pulls the permit, you pay the fee, and the electrician does the work under that license. The electrical permit must be inspected separately from the building permit. Plan for two inspections total: rough electrical (before drywall) and final electrical (after trim). If the kitchen remodel also requires plumbing or gas work, those are additional permits.
What's the difference between coastal and foothills frost depth in Redwood City?
Coastal and Bay-facing properties (sea level to ~1,000 feet elevation) use a 12-inch frost depth for deck footings and shallow foundation work — well above the IRC minimum of 36 inches for non-frost zones. Foothills and mountain properties (1,000+ feet elevation) jump to 18–30 inches depending on exact elevation and aspect. This affects deck footing cost directly: deeper footings mean digging deeper and buying more concrete. If your property is near the boundary (1,000–1,500 feet), call the Building Department and ask them to confirm your frost depth in writing. Don't guess — footing inspection failures are expensive to fix.
What happens if I start work without a permit?
If Building Department inspectors spot unpermitted work, they issue a stop-work order and require you to cease immediately. You'll then need to file a retroactive permit, pay double the original fee (or a retroactive penalty), submit for full plan check and inspection, and correct any work that doesn't meet current code. If the unpermitted work is structural or electrical, you may be required to hire a licensed engineer to certify it safe before inspections can proceed. Unpermitted work also clouds title and makes resale complicated. Insurance claims may be denied if work was unpermitted. The fastest, cheapest path is always to pull the permit before you start.
Is there a way to speed up plan check?
The main way is to submit a complete, code-compliant application on the first try. Include site plans showing property lines and setbacks, floor plans, sections, elevations, structural calcs if required, electrical one-lines, and plumbing riser diagrams. For additions and remodels, show existing and proposed conditions clearly. Use a qualified designer or engineer if the work is complex; their stamp on plans signals competence and reduces reviewer questions. Mountain and slope properties especially benefit from professional design — DIY slope-stability sketches get marked incomplete. Redwood City also offers pre-application meetings (call the Building Department to schedule) where you can ask reviewers what documentation they'll need before you file. That costs nothing and saves 2–3 weeks of back-and-forth.
Do I need an environmental or tribal review for my project?
Depends on location and scope. Work near creeks, wetlands, or sensitive habitat may trigger environmental review under the California Environmental Quality Act (CEQA). Redwood City is within or adjacent to tribal territories; some projects may require tribal consultation. The Building Department will flag this during intake — they'll tell you if your project needs it. If you're unsure, submit a site plan early in pre-design and ask. Environmental/tribal reviews can add 4–8 weeks to permitting, so get clarity early.
What if my project is on a steep slope or in a fire zone?
Redwood City foothills and mountain properties often sit on steep slopes or in State Responsibility Areas (high fire-risk zones). Slope work may require a geotechnical engineer's report and slope-stability analysis. Fire-zone properties face Cal Fire defensible-space requirements and may need fire-resistive materials (roofing, siding, etc.). Both add plan-check time and cost. The Building Department will tell you at intake if your property is in a fire zone (check San Mateo County mapping, too). If slope or fire risk applies, budget extra design time and hire a professional engineer early. DIY applications fail slope and fire reviews reliably.
Ready to file your Redwood City permit?
Start with a specific question: Do you need a permit for your project? Call the Building Department at 650-780-7250 (verify current number) or visit the online portal to see application requirements. Bring your property address, a sketch of the project, and a clear sense of scope — the faster you answer those three things, the faster you move toward filing. Most Redwood City homeowners file online and get plan-check feedback within 2–3 weeks. If your project involves electrical, plumbing, gas, or structural work, have a licensed contractor or engineer involved from day one — they'll spot code issues you won't.