Frequently Asked Questions - ADU in San Francisco, CA
Straight answers about building an accessory dwelling unit in San Francisco, from cost to permits to how long it actually takes. Russ Delmar and our local team put this together based on the questions we hear most from homeowners in the Bay Area.
Pricing & Cost FAQs
An accessory dwelling unit in San Francisco typically costs between $350,000 and $650,000 depending on whether you're converting existing space or building detached ground-up construction. Garage conversions run lower, usually $180,000 to $280,000, because the foundation, framing, and roof are already there. Detached units with new foundations, utility runs, and full kitchens cost more. Site conditions matter a lot in San Francisco: hillside lots, soft soil, seismic retrofitting requirements, and parking-preservation rules all move the number. We give you a written line-item price before any work starts, so you know exactly what you're paying for. Call (707) 760-0502 to schedule a free estimate.
The cheapest ADU in San Francisco is a garage conversion, generally $180,000 to $280,000 because the structure already exists. You're paying for insulation, drywall, electrical, plumbing, windows, and a kitchen or bath, not new framing and a roof. Some homeowners save more with prefab panels from brands like Boxabl, which arrive flat-packed and assemble quickly on site. Keep in mind that San Francisco has strict seismic requirements even for conversions, so the structural work isn't optional. A finished conversion still needs permits, inspections, and a final certificate of occupancy. Call (707) 760-0502 and we'll price your exact garage or basement conversion.
Yes. An ADU adds both resale value and rental income potential to a San Francisco property. Buyers consistently pay more for homes with a legal accessory unit because the unit generates income that offsets the mortgage. In neighborhoods like the Sunset, Richmond District, and Bernal Heights, an ADU can add several hundred thousand dollars to resale value, plus ongoing rent. The key is that the unit must be legal: permitted, inspected, and with a certificate of occupancy. Unpermitted units become liabilities at sale time. We handle permits and inspections so your ADU adds value instead of headaches. Call (707) 760-0502 to talk through your property.
No. Every job gets a written price before any work starts, and that's a Kingswell Guarantee standard. The price we put in writing covers the agreed scope. If you change the scope, like adding a second bathroom or upgrading fixtures, we write a change order with its own price and you approve it before we proceed. What you won't see is a surprise bill at the end for something we "discovered" that was actually visible from day one. If site conditions genuinely change, like hidden foundation damage on a hillside in Noe Valley, we show you what we found, explain it, and price the fix with you. Call (707) 760-0502 for a written estimate.
Service & Process FAQs
The process has five stages: design and feasibility, permits, site preparation, construction, and final inspection. We start by assessing your lot, zoning, and existing structures, then produce drawings that meet San Francisco Building Code and state ADU law. Once permits are submitted to the Department of Building Inspection, we wait for approval. Then construction begins: foundation, framing, mechanical, electrical, plumbing, finishes. Finally, a city inspector signs off and you get a certificate of occupancy. The whole timeline from first meeting to move-in is generally 10 to 18 months in San Francisco. Russ Delmar walks every client through the stages before we start.
An ADU in San Francisco typically takes 10 to 18 months from the first design meeting to the final inspection. Permitting alone can run 3 to 6 months depending on the Department of Building Inspection's workload and whether your project needs planning review. Construction is usually 6 to 12 months. Garage conversions trend faster because there's less structural work. Detached units on hillside lots with foundation work and retaining walls trend slower. We give you a schedule with the written proposal, and we show up in the window we gave. Call (707) 760-0502 and we'll give you an honest timeline for your specific project.
Yes. We handle the full permit process with the San Francisco Department of Building Inspection, including plan review, over-the-counter permits where allowed, and scheduling every inspection. San Francisco has specific ADU rules: the city streamlined the process under state law AB 68 and AB 1033, but local zoning still applies for lot coverage, setbacks, and historic districts. We prepare drawings, submit applications, respond to plan check comments, and pull the approved permit. Inspections are coordinated by our team and we stay on site until the final sign-off. Call (707) 760-0502 to talk about your project's permitting path.
Yes, in most cases. San Francisco state ADU law requires the city to allow at least one accessory dwelling unit on any lot zoned for residential use, including small and sloped lots. The design has to work with the terrain though. Hillside lots in areas like Twin Peaks, Glen Park, and Diamond Heights often need retaining walls, pier foundations, or stepped floor plans. Small lots may require a compact footprint or a stacked unit over a garage. We've designed and built on lots under 2,500 square feet. Russ Delmar and our team will tell you honestly what your lot can support. Call (707) 760-0502 for a free site assessment.
Yes. We serve San Francisco and the surrounding Bay Area: Oakland, Hayward, Richmond, Daly City, San Leandro, San Rafael, Hillsborough, Martinez, San Bruno, San Carlos, and Millbrae. Each city has its own ADU ordinance and permit process. Oakland has a streamlined pre-approved plan program. San Leandro and Hayward allow detached units under state standards. San Rafael and Hillsborough have hillside and fire-zone requirements that affect design. We know each city's rules and we design to them from day one, not after we've submitted a plan that won't pass. Call (707) 760-0502 to see if we cover your address.
Check four things: zoning and lot coverage, setback requirements, existing utility connections, and whether your property is in a historic district. San Francisco historic districts like Liberty Hill and parts of the Mission have additional design review, which can add months. Also check your sewer lateral condition; on older San Francisco homes, an ADU can push a failing lateral into replacement territory, which costs extra. We handle the whole evaluation for you. During the estimate, we walk the property, review city records, and flag anything that will affect cost or schedule before you commit. Call (707) 760-0502 for a free walkthrough.
Brands & Parts FAQs
We can. Prefab and panelized systems work well on many San Francisco lots, especially where the access is tight and traditional stick framing would mean weeks of material staging. We've worked with panels from Boxabl and systems from Plant Prefab, which manufacture off-site and assemble quickly on location. Prefab can shorten construction time and reduce weather delays, which matters in San Francisco's summer fog belt. The tradeoff is that prefab limits custom design changes once the panel set is ordered. We'll show you stick-built and prefab pricing side by side so you can decide with real numbers. Call (707) 760-0502 for both options on paper.
James Hardie fiber cement siding holds up well to San Francisco's coastal fog, salt air, and temperature swings. The fog belt through the Outer Sunset and Richmond District keeps wood siding wet for months, which invites rot and pests. Fiber cement doesn't absorb fog moisture the way wood does. For trims and soffits, we use rot-resistant materials and proper rainscreen details behind cladding. Metal roofing also performs well on San Francisco ADUs because it sheds fog drip and lasts decades with minimal maintenance. Interior-wise, vapor barriers and proper ventilation are non-negotiable in San Francisco's damp microclimates. Call (707) 760-0502 to talk materials for your specific neighborhood.
No. Tuff Shed and similar backyard storage buildings don't meet San Francisco's requirements for a legal accessory dwelling unit. An ADU needs a permanent foundation, insulation to Title 24 energy standards, plumbing, electrical service, and approval from the Department of Building Inspection. A storage shed isn't engineered for habitation and won't pass a residential inspection. That said, we've had homeowners start with the idea of a shed conversion and end up with a well-designed stick-built or prefab ADU on a proper foundation. If you want the shed aesthetic, we can build a legal unit that looks like one. Call (707) 760-0502 to talk options.
Licensing & Insurance FAQs
Every pro working under the Lodgewick name in San Francisco is required to hold the license and insurance their state requires. We follow the same standard across every Kingswell company: before a project starts, you receive proof of license and insurance for your records. The written proposal includes our license information and contact details. In California, ADU builders must hold a General B contractor license from the Contractors State License Board. We won't ask you to take our word for it; we'll show you the paperwork. Call (707) 760-0502 and we'll send you the documentation before you sign anything.
Russ Delmar leads our local San Francisco team. Every pro working under our name is required to hold the license and insurance their state requires. We coordinate the full project: design, permits, construction, and inspections. We work with a network of local subcontractors for specialized trades like electrical, plumbing, and foundation work, which is standard for residential construction in California. The important thing is that one team is accountable for the whole project: the price, the schedule, and the guarantee. You have one point of contact, not a phone tree. Call (707) 760-0502 to meet the team in person.
Yes. Every ADU we build is permitted through the appropriate city building department, whether that's the San Francisco Department of Building Inspection or the equivalent in Oakland, San Rafael, or any other city we serve. We don't build unpermitted units, and we don't ask homeowners to pull owner-builder permits so we can avoid oversight. The permit is what protects you: it ensures the work is inspected, the unit is legal, and your property value and insurance stay valid. Unpermitted ADUs in San Francisco can trigger enforcement actions and complicate a home sale. Call (707) 760-0502 if you want a straight answer about your specific situation.
Emergency & Response FAQs
Yes. This situation is more common in San Francisco than people realize, especially in older homes where a basement or back room was finished without permits decades ago. Legalizing an unpermitted ADU means bringing it up to current code: structural, electrical, plumbing, egress windows, and fire separation, then filing for the proper permits and passing inspections. Depending on the unit's condition, the cost can range from a moderate retrofit to a full rebuild. We tell you which one you're facing before any work starts. Call (707) 760-0502 to have Russ Delmar and our team look at your unit.
It depends on the scope, but a garage conversion or detached ADU causes less disruption than you'd expect. The work happens in one contained area, and we set up dust barriers, walkway protection, and daily cleanup. The Kingswell Way says leave the place cleaner than we found it, and that's the standard on every site. For detached units, you'll see deliveries and crews in the yard but not inside your home. For attached conversions, expect noise during work hours and some dust control measures. We give you a schedule and tell you what to expect each week. Call (707) 760-0502 to talk through your specific project.
Call (707) 760-0502. Our office is open Monday through Friday from 7:00 AM to 7:00 PM and Sunday from 7:00 AM to 7:00 PM, closed Saturdays. A live coordinator answers and connects you with Russ Delmar and the local team. During construction, you'll also have the direct contact for your project lead. We don't leave you guessing about who to call when something comes up. If you have a question about schedule, materials, or an invoice, call us. If you need something in writing, we send it. Call (707) 760-0502 and you'll reach a person, not an automated system.
Warranty & Guarantees FAQs
Every job is covered by the Kingswell Guarantee. It's a written promise: a written price before any work starts, a real arrival window, a clean job site, and a written guarantee on the work. If a repair fails inside the guarantee period, we come back and fix it at no charge. The guarantee is printed in your proposal and on our terms page; you don't have to ask for it and you don't have to remember a verbal promise. Russ Delmar and our team stand behind every ADU we build in San Francisco. Call (707) 760-0502 and we'll send you a copy of the guarantee before you sign.
The Kingswell Guarantee covers our work in writing for the period stated on your proposal. We put the exact terms, what's covered, and what's excluded in the document you sign, so there's no ambiguity later. If a repair fails inside the guarantee period, we come back and fix it at no charge. We don't ask you to chase subcontractors or file claims yourself; we handle it. That's the whole point of the guarantee: you know what you're getting before you pay, and you know what happens if something fails after we leave. Call (707) 760-0502 for a written proposal with the full guarantee terms.
Manufacturer warranties cover their materials, and our workmanship guarantee covers how those materials are installed. For example, James Hardie provides its own product warranty on fiber cement siding, and we pass the manufacturer documentation to you at project close. The Kingswell Guarantee covers our labor and installation. If a material fails because of a manufacturing defect, we help you process the manufacturer claim. If something fails because of how it was installed, that's on us, and we fix it at no charge inside the guarantee period. Call (707) 760-0502 and we'll explain exactly what's covered on your specific project.
Call (707) 760-0502. If a repair fails inside the guarantee period, we come back and fix it at no charge. That's the Kingswell Guarantee in writing. We don't argue about who's responsible; if it's our workmanship and it's inside the coverage period, we schedule the return, show up in the window we gave, and make it right. Our office is open Monday through Friday from 7:00 AM to 7:00 PM and Sunday from 7:00 AM to 7:00 PM. Russ Delmar and our local team take guarantee calls seriously because the guarantee is the whole reason homeowners choose Lodgewick ADU San Francisco.
Written by Russ Delmar, Owner at Lodgewick ADU San Francisco, serving San Francisco and the Bay Area since the branch opened.
Still Have Questions?
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(707) 760-0502