A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Los Altos
Adding an accessory dwelling unit in Los Altos typically runs $180,000 to $450,000 for a custom detached build, with prefab installations landing between $120,000 and $280,000. We know those numbers matter before you pick up the phone, so we put them in writing. The team here at Lodgewick ADU San Jose works across Los Altos daily, from the winding streets off Foothill Expressway to the newer subdivisions near Rancho San Antonio, and we know what the city’s planning department expects before plans ever hit the counter. If you want straight answers about ADU construction in Los Altos, call (669) 266-4319 and talk to a live person, not a voicemail.
Why Lodgewick ADU San Jose Is Los Altos’s Preferred ADU Builders Company
Lodgewick ADU Builders is the Kingswell family’s ADU company, established in 2010. Russ Delmar leads our team, and he’s built the company on a simple idea: write the price down before work starts, then honor it. Los Altos homeowners have told us that’s rare. They’ve dealt with contractors who gave a verbal number, then came back with a change order two weeks in. Under The Kingswell Guarantee, every project gets a written price, a defined arrival window, a clean job site, and a written guarantee delivered before a single nail is driven.
Our crews serving Los Altos are background-checked and uniformed, so you know exactly who’s on your property. Hand us a tricky lot on a hillside near Los Altos Hills, a mid-century ranch off Springer Road, or a two-story addition behind a heritage oak near Loyola Corners, and we’ll plan around the grading, the roots, and the city’s design review. We also coordinate with local prefab manufacturers, including Plant Prefab and Abodu, for homeowners who want factory-built precision with faster site time.
When you call us from Los Altos, a live person answers. 24 hours a day, 7 days a week. Not a chatbot, not a voicemail loop. That matters when you have a question about your build schedule or your written guarantee at 9 p.m.
ADU Plans in Los Altos
ADU Plans in Los Altos are where most projects win or lose before construction starts. The city’s zoning code, minimum lot size rules, and design review process mean a plan set that works in Santa Clara won’t necessarily pass in Los Altos. We prepare plans that account for setbacks, height limits, heritage tree protection zones, and Title 24 energy requirements from the first draft.
Site Assessment and Feasibility
Before plans are drawn, we walk the lot. In Los Altos, that means checking where mature oaks and redwoods sit, how runoff moves across the property during winter rains, and whether the existing foundation can support an attached ADU. Our team documents utility locations and any unpermitted structures that might need to be brought into compliance before the city signs off.
Permit-Ready Drawing Sets
We produce full plan sets: architectural drawings, structural calculations, Title 24 energy compliance, and drainage details. Los Altos requires solar or other renewable energy generation on new ADUs, so we factor panel placement and conduit runs into the drawings from day one. Expect plan preparation to cost $8,000 to $25,000 depending on lot complexity and whether you need a survey.
ADU Contractor in Los Altos
As an ADU Contractor in Los Altos, we handle the build from foundation to final inspection, and we pull every permit. Most detached ADU projects in Los Altos take 6 to 12 months from groundbreaking to certificate of occupancy. Attached ADUs and garage conversions run faster, often 4 to 8 months, because the structure’s shell already exists.
Construction Management Done the Kingswell Way
Our crews show up in the arrival window we gave you in writing, keep the site tidy at the end of every day, and leave your property cleaner than we found it. You get a written schedule and a single point of contact who answers your questions directly. No chasing subs, no wondering who’s showing up tomorrow.
Final Inspections and Closeout
We walk the unit with you before the city’s final inspection, fix anything that isn’t right, and hand over a written guarantee covering every element of the build. If something fails within 365 days, we come back and make it right. That’s the 365-Day Done Right Promise, and it’s in writing on every Los Altos project.
Trusted Brands We Service in Los Altos
For Los Altos homeowners who want a prefab ADU, we work directly with Plant Prefab, Abodu, and Tuff Shed, plus we spec James Hardie siding and trim on nearly every custom build because it holds up to the Bay Area’s wet winters and dry summers without warping. We know these brands’ panel systems, tolerances, and lead times, which means we can give you accurate pricing and a realistic schedule before you commit. We also stock common components locally so we’re not waiting on a freight shipment when a project needs to move forward.
Common ADU Builders Problems We See in Los Altos Homes
- Heritage tree and setback conflicts. Los Altos protects healthy oaks and redwoods, and many lots have trees within 20 feet of the proposed build zone. We flag these on the first site visit so you don’t pay for plans the city will reject.
- Hillside drainage and foundation slope issues. Winter rains on sloping lots near Los Altos Hills and the Adobe Creek corridor can saturate soil and stress new foundations. We design drainage and waterproofing to handle it from day one.
- Unpermitted existing structures. Los Altos has a stock of older detached garages and converted spaces that were never legalized. Sorting out what’s allowed under the city’s ADU amnesty program is part of what we do before plans are submitted.
- Title 24 energy and solar requirements. New ADUs in California must meet current energy code, including renewable generation. We integrate solar, mini-split HVAC, and EV charger rough-ins into the build instead of bolting them on later.
Pricing for ADU Builders in Los Altos, CA
Here are the numbers we quote for Los Altos, and we stand behind them in writing. A prefab or modular studio ADU runs $120,000 to $280,000 including site work, foundation, and utility connections. Custom detached one-bedroom units run $180,000 to $350,000. Two-bedroom custom ADUs with high-end finishes, two-story designs to save yard space, and premium systems run $300,000 to $450,000. Garage conversions typically land at $100,000 to $220,000, a junior ADU inside an existing home at $80,000 to $150,000. What moves the number: lot slope, foundation type, distance to utility connections, finish level, and whether you choose stick-built or prefab. You’ll get a written line-item price before any work begins. Call (669) 266-4319 to schedule a free estimate.
We Also Serve Cities Near Los Altos
Our crews work across the South Bay and Peninsula. If you’re in Palo Alto, Portola Valley, Santa Clara, or Los Gatos, we handle ADU projects there too, and we’ll bring the same written pricing and 365-Day Done Right Promise. For additions beyond ADUs, talk to our Home Addition Contractor in Los Altos team.
Serving Los Altos, CA - Our Local Coverage Area
We’re based in the Los Altos area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Builders in Los Altos
Once we finish the site assessment and you approve the written plans, we can typically start site work within 4 to 6 weeks, depending on the city’s plan check turnaround. Prefab units from Plant Prefab or Abodu can shave a month or more off the front end because the factory builds while the foundation goes in. Call (669) 266-4319 to get your project on our schedule.
Yes, we build across all of Los Altos, including the neighborhoods around Loyola Corners, the Country Club area off Miramonte Avenue, the hillside lots near Rancho San Antonio, and the central district near downtown. We know the different setbacks and design review expectations across the city’s zoning map.
ADU construction is planned work, not emergency repair, but if something goes wrong on an active build site, like a weather-related issue or a material failure, our crews respond quickly and a live person answers your call 24/7. If your project is still under the 365-day guarantee period, we come back at no charge. Call (669) 266-4319 and we’ll dispatch a crew.
Los Altos runs higher than Santa Clara and San Jose, mostly because the city’s design review, heritage tree protections, and hillside grading requirements add plan time and engineering. Expect to pay 10% to 20% more than you’d pay for the same unit in a flat, less-regulated neighboring city. We’ll show you exactly where those costs come from in the written estimate.
Every project includes our written 365-Day Done Right Promise. If any work fails within one year of completion, we return and make it right at no charge. That covers structural elements, roofing, waterproofing, finishes, and systems installs we performed. The guarantee is in writing before construction starts. Call (669) 266-4319 for an exact quote and a copy of the guarantee terms.
Written by Russ Delmar, Owner at Lodgewick ADU San Jose, serving Los Altos and the greater South Bay.
