Home Addition Drawings · Redwood City, CA
Permit-Ready Home Addition
Drawings for Redwood City, CA
Expand your home with a permitted room addition, second story, or family room extension. We deliver complete, code-compliant drawing sets for Redwood City's building department — 14-day money-back guarantee.
14-day money-back guarantee · permit-ready delivery
Local Intelligence
What Redwood City Homeowners Need to Know Before Submitting
Size & Zoning Rules
Any new square footage added to your Redwood City home counts against the same zoning envelope that governs ADU size, meaning large additions may affect your ability to add a future ADU. Redwood City's current ADU size cap is 1,000 sq ft — within the typical range for most floor plan configurations.
Redwood City does not impose an owner-occupancy requirement, so you can rent both the main home and any ADU or conversion as investment units.
If the addition creates a second unit or is later converted to a rental, Redwood City's ADU market supports approximately $4,200/month for a 2-bedroom unit.
Permit Process & Fees
Building & Code Enforcement Services permit fees for this project type typically range from $7,000 to $11,000 depending on project valuation and scope. Plan check runs approximately 12 weeks — though each correction cycle adds 3–6 weeks, which is why code-compliant drawings matter so much.
Addition permit packages submitted to Building & Code Enforcement Services must include a site plan, floor plans, all four elevations, an electrical plan, and energy compliance documentation — plus stamped structural drawings are always required for any load-bearing elements, second-story work, or new foundation.
Visit Building & Code Enforcement Services ↗Construction Cost Context
Redwood City's home addition construction costs run $250–$490 per square foot — a wide range driven by labor markets, local code complexity, and finish level. Our drawings are priced at a fraction of what a full-service architect would charge to produce the same permit set.
⚠ Common Pitfall in Redwood City
If your ADU is 750 sqft or larger, Redwood City applies development impact fees, which include school district fees from Sequoia Union High School District—this can add several thousand dollars to your project costs unexpectedly. Additionally, homeowners in areas with older sewer infrastructure often face mandatory lateral upgrades, which can run $10,000–$15,000 and require coordination with Public Works before permits are approved.
Expert Verdict — Marcus Reid, Licensed Designer
"In my experience with Redwood City submittals, that 12-week plan check figure and the $/sqft cost number are really state-level estimates, not local truth — I'd get quotes from at least two Peninsula-based contractors and call Building & Code Enforcement Services directly before you bank on either one holding up. Also worth noting: with HOA presence at 30%, don't be surprised if a CC&R review adds its own delay on top of whatever the city hands back."
Market Context
Redwood City has a median home value of $1,550,000. Comparable renovation projects in this market typically add 30% to resale value.
Neighborhoods in Redwood City with the strongest home addition and resale value potential include Farm Hill, Edgewood Park, Mount Carmel, Woodside Plaza, Eagle Hill. Top ADU pick with large 7,000-12,000 sq ft lots, detached single-family housing stock, and strong $2,800-$3,500/mo rental demand near downtown employers.
Permit Process
Permit applications are reviewed by the Building & Code Enforcement Services, with a plan check timeline of approximately 12 weeks. Permit fees in Redwood City range from $7,000 to $11,000 depending on project scope.
Redwood City falls within Seismic Design Category E, which affects structural requirements for any new addition tying into the existing structure.
Local Financing Resources
Local Home Addition Lenders in Redwood City
These lenders offer HELOC, construction, and renovation loans for home addition projects in San Mateo County. Compare terms before committing.
Dedicated ADU HELOC product with variable rate starting at 8.25% APR, line amounts from $10,000 up to $400,000, with a 2-year interest-only draw period followed by a 20-year repayment term; branch located at 1105 Veterans Blvd, Redwood City.
Visit Lender ↗Local San Mateo County credit union with branches including Redwood City; home equity loans/lines of credit from $25,000 to $600,000 with introductory 5.99% APR for 6 months, terms up to 15 years, borrowing up to 75% of home value.
Visit Lender ↗California-based credit union offering construction loans specifically for ADUs (fixed- and adjustable-rate terms) including a dedicated ADU loan product developed with Napa Valley Community Foundation to help homeowners finance second units.
Visit Lender ↗Bay Area tech-industry credit union with branches in Cupertino, Palo Alto, and San Jose; offers HELOCs and home equity loans that can fund ADU construction/renovation for eligible tech-company employees and their families.
Visit Lender ↗San Mateo County-based credit union offering construction loans specifically for ADUs (fixed- and adjustable-rate terms) including a dedicated ADU loan product developed to help homeowners finance second units in the Bay Area.
Visit Lender ↗Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.
Local Build Partners
Vetted Home Addition Contractors in Redwood City
We draw the plans. These contractors build the addition. Independent — no referral fees paid or received.
Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.
Free — No Obligation
What Will Redwood City Let You Add?
Setbacks, lot coverage, and height limits decide your addition before a single line is drawn. Send us the address and we’ll tell you what’s actually approvable — free, before you commit to a design.
- ✓Maximum footprint your lot and setbacks allow
- ✓Lot-coverage and height limits in Redwood City
- ✓Whether your addition triggers structural or energy upgrades
- ✓Realistic plan-check timeline for your project
- ✓A straight answer within 48 hours
Review My Project — Free
Takes 60 seconds. We'll deliver your personalized report within 48 hours.
Request Received
Your feasibility report is being prepared. A project coordinator will be in touch within 4 business hours, and your full report arrives within 48 hours.
Drawing Package Details
What's Included in Your Redwood City Home Addition Package
What You Get
What's in Your Redwood City Home Addition Package
One-time fee, no retainer, no hourly billing — your exact scope and price confirmed on a free call.
- ✓Site plan
- ✓Floor plans (existing + proposed)
- ✓All 4 elevations
- ✓Electrical plan
- ✓Title 24 energy compliance
- ✓PDF + DWG delivery
- ✓10 business day turnaround
- ✓Everything in Starter
- ✓Stamped structural drawings
- ✓Foundation plan
- ✓Roof framing plan
- ✓Window & door schedules
- ✓1 round of revisions
- ✓Everything in Standard
- ✓3D rendering
- ✓Cross-section details
- ✓Material specifications
- ✓HOA submission package
- ✓2 rounds of revisions
- ✓Priority 5-day turnaround
After You Order
Your Addition Drawings in 3 Steps
Submit Your Project Details
Share your property address, existing floor plan (if available), and the addition scope. We assign your project coordinator within 4 business hours.
We Draft Your Drawings
Our team designs your complete addition drawing set — engineered for Redwood City's building department requirements and CA CBC code. Delivered in 10 business days.
Submit to Your Building Dept
Download your complete package and submit to Building & Code Enforcement Services. We support plan check corrections at no extra charge.
Common Questions
Redwood City Home Addition FAQs
Do I need a permit for a home addition in Redwood City? +
Yes — any structural addition to your home in Redwood City requires a building permit. This applies to room additions, second-story additions, sunrooms, and attached garages. You'll need permit-ready drawings before the building department will accept your application. Our packages are formatted specifically for Redwood City's submittal requirements.
How much does a home addition cost in Redwood City? +
Home additions in Redwood City typically cost between $150–$500 per square foot depending on the scope, finishes, and structural complexity. A 600 sq ft addition ranges from $90,000 to $300,000. Second-story additions cost more than ground-floor extensions due to structural requirements. Contact us to discuss drawing package options for your project.
What drawings are required to permit a home addition in Redwood City? +
Redwood City's building department requires: a site plan showing the addition's footprint and setbacks, floor plans for all affected levels, all four exterior elevations, an electrical plan, and energy compliance (Title 24 in California). Structural plans stamped by a licensed engineer are required for any load-bearing elements — included in our Premium package.
How long does the permit process take for a home addition in Redwood City? +
Plan check in Redwood City typically takes 12 weeks for home additions. Additions with structural components may require additional review. Complete, code-compliant drawings significantly reduce correction cycles — each cycle adds 3–6 weeks. Our drawings are engineered to pass on the first submittal.
What setbacks apply to home additions in Redwood City? +
Redwood City enforces minimum setbacks from property lines for all additions: typically 4–5 ft side setbacks and 5 ft rear setbacks, though these vary by zoning district and lot size. Your addition must stay within the buildable envelope. Our site plan documents existing and proposed setbacks and flags any zoning variances required.
Do I need structural drawings for a home addition in Redwood City? +
Yes, for most additions. Any load-bearing walls, new foundations, second-story construction, or roof structure changes require stamped structural drawings from a licensed engineer. California's CBC (California Building Code) and seismic requirements make structural plans mandatory for most addition types. Our Standard and Premium packages include stamped structural drawings.
How much do home addition drawings cost in Redwood City? +
Our permit-ready home addition drawing packages for Redwood City include everything your building department requires — floor plans, elevations, structural, and energy compliance. Every package is engineered for CA code compliance and formatted for Redwood City's building department. 14-day money-back guarantee.
Will a home addition increase my home's value in Redwood City? +
In Redwood City, where median home values are approximately $1,550,000, a permitted home addition adds square footage that appraisers value as part of the home's gross living area. Return on investment varies by addition type — master suite additions, family room expansions, and additional bedrooms typically recoup 50–75% of project cost in appraised value in CA markets.
Can I add a second story to my home in Redwood City? +
Second-story additions are permitted in most Redwood City residential zones, subject to height limits and design review requirements. California generally requires ministerial permit approval, but some cities impose design compatibility or neighborhood compatibility review for second stories. Our drawings cover all levels including foundation upgrades, shear walls, and roof framing required for vertical additions.
Nearby Cities
Also Available in Redwood City
Adding an ADU instead? See our ADU design service.
Next Steps
Ready to Move Forward With Your Redwood City ADU?
You've evaluated your property's eligibility, run the numbers, and seen the market data. The next step is getting permit-ready architectural drawings to submit to Building & Code Enforcement Services.
Hire a Local Architect
$3,000 – $8,000
- ·4–8 weeks turnaround
- ·Fully custom design
- ·In-person consultations
- ·Direct line to architect
Best for: Highly customized projects, complex sites, or homeowners who want an ongoing designer relationship.
Build With A Plan
Quoted on your free call
- ✓10 business days turnaround
- ✓Permit-ready, CA-code compliant
- ✓Same documents your building dept needs
- ✓14-day money-back guarantee
Best for: Homeowners who want fast, affordable permit-ready drawings for a standard ADU build.
Both options produce permit-ready architectural drawings accepted by Building & Code Enforcement Services. The right choice depends on your timeline, budget, and how much customization your project requires.