Do You Actually Need Neighbor Approval to Build an ADU? No.
Most Redwood City homeowners on single-family lots already have the right to build — no public hearing, no neighborhood vote.
Most R1 Lots Already Qualify — By Right
California law changed the process entirely. Under SB 9 — the state law that expanded housing rights on single-family zoned lots — and earlier ADU reforms, most R1-zoned properties in Redwood City now qualify for at least one ADU, and in many cases one JADU, through by-right approval.
By-right approval means ministerial review only. The city checks your plans for code compliance. It does not hold a public hearing. It does not notify neighbors. It does not give adjacent homeowners a vote on your project. If your parcel meets objective zoning standards, the permit must be issued. That's state law, not a loophole.
Bark and Build constructs detached and attached ADUs on R1-zoned properties throughout Redwood City and across San Mateo County — handling eligibility confirmation, design, permitting, and construction under CA License #1119304.
Licensed by the CSLB under CA #1119304 — active & publicly verifiable.
How SB 9 Changed the Approval Process for R1 Neighborhoods
SB 9 didn't just make ADUs easier to build — it removed an entire layer of government review most homeowners didn't realize was optional. Before 2020, building an ADU in Redwood City's residential neighborhoods often meant navigating discretionary review, where neighbors could object, planning commissioners could weigh in, and no outcome was guaranteed. That system no longer applies to most single-family parcels.
Here's what most homeowners don't realize: the by-right pathway has been the law for years. The assumption that special approval is required hasn't caught up to the actual code.
Redwood City's R1 neighborhoods span a range of lot sizes — from compact 5,000-square-foot parcels in Stambaugh-Heller to larger lots in the Farm Hills and Emerald Hills corridors. Lot size affects what you can build and where it can sit. It does not change whether you have the right to build. The parcel-level details — setback depth, existing lot coverage, utility access — determine the buildable envelope, and those are engineering questions answerable before a dollar goes to design.
A Homeowner Who Waited Two Years for Approval That Was Never Required
We worked with a homeowner in the Farm Hills area of Redwood City who had been researching an ADU for almost two years. She'd attended a neighborhood meeting, spoken to a planning consultant, and formed the impression that her neighbors would need to sign off before anything could move forward. None of that was true.
When our team reviewed her parcel, we confirmed she was in an R1 zone. Her 7,200-square-foot lot had a rear yard with enough depth to position a detached ADU within the 4-foot minimum setback California law requires. Her existing lot coverage left room for a structure well within the allowable square footage. She qualified for by-right approval — ministerial review: the building department checks code compliance and issues the permit, full stop.
We submitted her permit package to San Mateo County. She received approval in under three months, and construction began shortly after. Two years of waiting; four months of actual process. That gap almost always traces back to one thing — a homeowner who didn't know which approval pathway applied. Our first job on every single-family ADU project is closing that gap before anything else starts.
We Confirm Your Parcel's Eligibility Before Any Design Money Is Spent
We review your lot's specific dimensions, setbacks, and coverage numbers before any design work begins — not after. This isn't a courtesy step; it's a structural protection for your budget. A floor plan that doesn't account for your actual rear setback, current lot coverage, or utility locations isn't a design asset — it's a document that will require corrections before it can be submitted.
Our team checks four things on every R1 parcel before design starts: lot dimensions and available buildable area; setback availability (California ADU law requires a 4-foot rear and side minimum for new detached ADUs); existing lot coverage after accounting for your house, garage, and structures; and utility access — water, sewer, and electrical connection points, because where those land affects where the ADU can practically sit.
Only after that review do we move to design. You know exactly what your parcel can support before any drawing begins.
By-Right Approval, Setbacks & Lot Coverage on an R1 Lot
By-right approval, ministerial review, and R1 zoning each mean something specific — and here's what the rules actually require for a new detached ADU.
From Parcel Review to Permitted ADU on an R1 Lot
Parcel Diagnostics
We start with a review specific to your address — lot dimensions, setback availability, current lot coverage, and utility access, confirmed before any design begins. We also verify permit jurisdiction; Redwood City runs its own building department at 1017 Middlefield Road, and its plan check has specific documentation expectations we account for upfront.
Design & Permit Preparation
Our in-house team draws your floor plans from your actual parcel data — site plan, architectural drawings, structural details, and Title 24 documentation, all prepared to current plan-check requirements. Because design and permitting happen under one roof, the drawings are already formatted for the department receiving them; one team holds the record from first line to final submittal.
Submission & Response
We submit directly to the relevant building department and handle each correction letter internally — revising the documents to address the department's specific comments and resubmitting on a tracked schedule, so you're never left interpreting technical plan-check language. We monitor each resubmittal cycle so the project doesn't stall between rounds.
Construction & Inspections
Once approved, our 25-person crew takes over under CA #1119304 — foundation through finish, every trade in-house, no coordination gap between the permit documents and the field. We schedule all required inspections with San Mateo County and resolve items before final sign-off. The project is complete when the permit is closed.
R1 ADU Projects Across Redwood City & San Mateo County
Each area presents different lot configurations — hillside parcels in Farm Hills and Emerald Hills, mid-sized lots in the Stambaugh-Heller corridor, and denser blocks near downtown — and our parcel review is calibrated to those differences.
Inside the existing home instead? See our JADU conversion page.
ADU Eligibility Questions for Single-Family Homeowners
Yes, in most cases. SB 9 applies to single-family residentially zoned parcels throughout California, including R1-zoned properties in Redwood City. There are limited exceptions — properties in historic districts, certain coastal zones, or lots that don't meet minimum size thresholds — but the majority of R1 parcels in Redwood City qualify. A parcel-level review confirms which rules apply to your specific address.
By-right approval means the city reviews your plans for objective code compliance only — setbacks, height, lot coverage, and similar measurable standards. There is no public hearing, no neighbor notification, and no discretionary judgment from a planning commission. If your plans meet the objective standards, the permit must be issued. This differs from how discretionary approvals worked before California's ADU reforms took effect.
Yes. California law permits a single-family lot to have one Junior ADU (created within the footprint of the existing home, up to 500 square feet) and one detached ADU (up to 1,200 square feet) on the same parcel. Both can be approved through ministerial review. They are treated as separate permit applications but can be developed concurrently.
California ADU law sets a 4-foot minimum setback from rear and side property lines for new detached ADUs on single-family lots. This applies statewide and overrides more restrictive local accessory-structure standards that predate the reform. Front setbacks generally follow the primary-structure standard for your zone. Our parcel review maps these against your specific lot dimensions before any design begins.
Lot coverage limits cap the percentage of your parcel that structures can occupy. If your existing house, garage, and outbuildings already consume most of that allowance, a full-size detached ADU may not fit within the permitted envelope. In those cases we evaluate whether a smaller-footprint ADU, a garage conversion, or a JADU within the existing structure is the more practical path — identified before design begins, not after you've spent money on plans.
Know Your R1 Lot's ADU Rights Before the First Design Dollar
Your single-family lot may already qualify for an ADU by right — a parcel review is the fastest way to confirm eligibility, not a planning consultation. Give us your address and we'll confirm setback availability, lot coverage, and by-right eligibility for your specific R1 parcel before any design spend is on the table.