About
Maya Okafor
Longbeam ADU Builders is an Oakland design-build contractor that has spent the last decade building backyard cottages, garage conversions and in-law units across the East Bay, San Francisco and the Peninsula. We start with a site visit, give you a fixed-price build estimate, coordinate the designer, permit expediter, lender and site crew, and hand you the keys with a one-year workmanship warranty. One project manager from first sketch to final inspection, and a weekly update every Friday.
4 offerings
ADU Building & Remodeling
ADU Care Plan
Keep your new backyard home in top shape after move-in. Twice a year a Longbeam technician inspects the roof, gutters, drainage, windows, plumbing, heat pump and water heater, replaces filters and smoke detector batteries, and sends a written report with photos. Members get priority service within two business days, 10% off repairs and help with warranty claims. Billed monthly; cancel anytime with 30 days' notice.
starting as low as $89.00
Book Now
ADU Building & Remodeling
Backyard ADU Open House Tour
Walk through three finished backyard homes in Oakland and Berkeley in one morning: a 420 sq ft factory-built studio, a two-bedroom detached cottage and a garage conversion. Meet the owners, the builder, the designer and a lender, ask what each one really cost, and see finishes up close. Saturday, November 14, 2026, 10:00 am to 1:00 pm. Start at our Oakland office; a shuttle runs between homes. Ticket includes the shuttle and coffee.
$15.00
Book Now
ADU Building & Remodeling
ADU Feasibility Site Visit
A 90-minute visit from a Longbeam project manager to answer the first big question: what can you build on your lot? We measure setbacks and access, check the sewer lateral, electrical panel and slope, flag trees and easements, and walk you through detached, attached and garage conversion options with a realistic cost range for each. Add a written zoning and utility memo to share with your designer and lender.
$495.00
Book Now
ADU Building & Remodeling
Free ADU Build Estimate
Thinking about a backyard cottage, a garage conversion or an in-law unit? Tell us about your lot and what you want to build, and a Longbeam project manager calls you within one business day. After a short call we send a written, fixed-price build estimate with a realistic timeline for your city. No cost and no obligation.
Request Info
Request Info
Reviews (0)
No reviews yet
FAQs
Q: How long does an ADU take from first visit to move-in?
Most detached ADUs take 12 to 18 months: 3 to 5 months for design, 2 to 6 months for permits depending on the city, and 5 to 7 months of construction. Garage conversions are usually 3 to 4 months faster.
Q: What does a backyard ADU cost in the Bay Area?
In 2026 most of our site-built ADUs land between $350 and $550 per square foot, all-in. Garage conversions start lower. Your site visit gives you a range for your lot; the build estimate is a fixed price.
Q: Which cities do you build in?
Alameda and Contra Costa counties, San Francisco, and San Mateo County. For the South Bay we partner with local crews and keep the same project manager and warranty.