Everything you need to build an ADU in Redwood City — lot eligibility, size limits, the eTRAKiT permit process, free GLADUR plans explained, and a full cost breakdown. All sourced from official City records.
Data verified 2026-07-09 · City of Redwood City · Municode Zoning Article 37 · CA HCD
Lot Eligibility
ADUs are permitted on most residential lots in Redwood City under California state law. Select your ADU type and zone below — results use verified City rules.
Instant eligibility check — Redwood City rules as of 2026-07-09
ADUs are allowed in R-1, R-2, R-3 zones. No minimum lot size. State law requires ADUs anywhere single- or multi-family housing is permitted.
California removed the owner-occupancy requirement in January 2020 (SB 13). You can build an ADU on a rental or investment property in Redwood City.
Some hillside parcels (e.g. Emerald Hills-adjacent neighborhoods) may require environmental or geotechnical review — verify per parcel with City Planning before finalizing design Contact City Planning at (650) 780-7234 before finalizing your design.
ADU Types & Sizes
Redwood City allows four ADU types. Sizes are governed by Zoning Code Article 37 with a state-law floor of 800 sqft the city cannot go below.
| Rule | Redwood City | Source |
|---|---|---|
| Max detached ADU size | 1,200 sqft | CA state max, adopted locally |
| Height — new detached ADU | 16 ft (25 ft two-story) | CA SB 897 (2022) |
| Side & rear setback (detached) | 4 ft minimum | CA Gov. Code §66332 |
| Setback for conversions | Waived entirely | CA Gov. Code §66332 |
| Parking required | None | CA Gov. Code §66333 |
| Minimum lot size | None required | CA Gov. Code §66310 |
| Owner-occupancy required | No | CA SB 13 (2020) |
| State approval clock | 60 days (ministerial) | CA Gov. Code §66333 |
Permit Process
Permits are submitted online through eTRAKiT . Standard review runs 3–8 weeks; the new AB 1332 pre-approved plan fast-track targets 30 days for qualifying plan sets.
AB 1332 Fast-Track — New 2025
Redwood City is implementing California's AB 1332 pre-approved ADU plan program. Qualifying plan sets — including free HEART/GLADUR plans — target a 30-day review. Site-specific engineering and a complete permit package still required.
#1: Incomplete plan set at intake
Missing sheets, incorrect file naming, or absent Title 24 CF1R triggers rejection at intake before plan review even begins.
#2: Utility capacity unresolved
Water/sewer capacity confirmation from RCSMD or CalWater is commonly required before permit issuance — order it before submitting plans.
Feasibility & Zone Verification
Confirm your zone (R-1, R-2, R-3), setbacks, lot coverage, and any hillside or environmental overlays. Emerald Hills-adjacent parcels may carry additional geotechnical review — verify parcel-by-parcel with City Planning at (650) 780-7234.
Evaluate Free Plans vs Custom Design
HEART Housing / GLADUR offer free pre-reviewed ADU plans that qualify for the City's 30-day AB 1332 fast-track. zHeight evaluates whether a free plan fits your lot's setbacks, soil conditions, and utilities — or whether a custom design is the faster, safer path.
Design & Engineering
Full permit-ready plan set: architectural drawings, structural calculations, and Title 24 CF1R energy compliance — prepared to Redwood City standards and eTRAKiT file naming conventions.
Submit via eTRAKiT
Open your permit application on eTRAKiT (https://permits.redwoodcity.org/etrakit) and upload your plan set online. No city office visit required. zHeight handles the submission and monitors the portal for review status updates.
Order water/sewer capacity confirmation from RCSMD or CalWater before submitting — commonly required before permit issuance.
Plan Review & Corrections
Standard review: 3–8 weeks. Pre-approved AB 1332 plans: 30-day target (new 2025). zHeight responds to all City correction letters until your permit is approved.
Permit Issued — Build
Pay permit fees to Redwood City online, receive your building permit, and schedule required inspections (foundation, framing, rough MEP, insulation, final) through the Building Division at (650) 780-7350.
Cost Guide
ADU costs break into three buckets. City permit fees are valuation-based — verify current amounts with Planning before budgeting. Ranges below are Bay Area market estimates.
$7,000 – $16,000+
zHeight flat-fee or custom quote. Includes architectural plans, structural calculations, and Title 24 CF1R. Hillside parcels requiring geotechnical coordination are at the higher end.
Valuation-based
Minimum $125. Plan check: 65% of permit fee (building/MEP/fire) or 25% (electrical). Full tiered schedule in the City's Master Fee Schedule PDF — call (650) 780-7234 for current amounts before budgeting.
$300 – $500+ / sqft
Paid to your licensed general contractor — not zHeight. Detached ADUs typically run $200K–$500K+ total. Conversions cost less; utility upgrades add cost. Get contractor bids after permit approval.
Verify Permit Fees Before Budgeting
The City of Redwood City uses a valuation-based fee table. The minimum permit fee is $125. Plan check fees are 65% of permit fee (min $125) for building, mechanical, plumbing, and fire; 25% of permit fee (min $125) for electrical. Full tiered amounts are in the City's Master Fee Schedule PDF — call Planning at (650) 780-7234 for current figures before you finalize your budget.
Want a cost estimate for your specific lot and ADU type?
Get a Free Project EstimateWhy zHeight
The City's AB 1332 program and HEART Housing / GLADUR's free ADU drawings are a genuine head start. Here's exactly what they include — and what still requires site-specific work before eTRAKiT will accept your submission.
Free plans are a real option. Free pre-reviewed detached ADU construction plans (studio through larger units) funded by BAAQMD grant. These qualify for the 30-day fast-track. If a free plan fits your lot, zHeight can assemble the site-specific permit package around it — adding structural engineering, Title 24 CF1R, and eTRAKiT submission — rather than starting from scratch.
| What you need | Free GLADUR Plans | zHeight Package |
|---|---|---|
| Plan drawings | Generic templates reviewed for a typical lot | Drawn specifically for your lot, setbacks, and configuration |
| Structural engineering | Generic calcs — may not match your soil or foundation | Site-specific structural calcs stamped by a licensed engineer |
| Title 24 CF1R | Not included — required separately before permit is issued | Included in every permit package |
| eTRAKiT submission | You submit and monitor yourself | zHeight handles submission and portal monitoring |
| Plan check corrections | You respond to City correction letters | zHeight responds to all corrections until permit is issued |
| Hillside / overlay review | Not addressed in generic plans | Flagged in feasibility and addressed in design |
The #1 cause of permit delays is an incomplete plan set at intake. zHeight's organized, City-compliant submission — correct file naming, all required sheets, Title 24 CF1R included — avoids rejection before review even begins.
zHeight provides architectural drawings, structural engineering, Title 24 compliance, and permit processing. We coordinate with your chosen licensed General Contractor throughout — we do not perform construction or contracting.
FAQ
Common questions about ADU eligibility, zoning, setbacks, the eTRAKiT portal, GLADUR plans, and costs in Redwood City.
Have a question not answered here?
Our Redwood City ADU experts typically respond within one business day.
Our Services
From a kitchen remodel to a full ADU build, zHeight handles the design, planning, and permitting. We work alongside your contractor — we are not the builder.
Design & permitting only. zHeight provides architectural drawings, structural engineering, Title 24 compliance, and permit processing. We do not provide construction or contracting services. We coordinate with your chosen builder throughout the process.
Detached ADU, attached ADU, JADU, and garage conversion plans — permit-ready and eTRAKiT-compliant for Redwood City.
Layout changes, kitchen and bath redesigns, wall removals, and structural updates. We draw the plans — you hire the contractor.
New rooms, bedroom additions, second stories, and square footage expansions — fully permitted and code-compliant.
Ground-up home builds and whole-home designs. Full plan set from concept to permit approval.
zHeight — Redwood City
We handle the complete permit package — architectural drawings, structural, Title 24 CF1R, eTRAKiT submission, and correction response — so your project moves from submission to permit.
All regulatory data verified 2026-07-09 against City of Redwood City ADU Ordinance, Zoning Code Article 37 (library.municode.com/ca/redwood_city), City Master Fee Schedule, CA Gov. Code §66310–66342, and CA AB 1332 (2023). Fee amounts beyond the stated minimums should be confirmed with City Planning at (650) 780-7234 before budgeting.