ADU Builder in Fort Bragg, CA

Detached ADUs Built by a Fourth-Generation Fort Bragg Builder

An accessory dwelling unit (ADU) is a second, complete home on the same lot as your house, with its own kitchen, bathroom, sleeping area and entrance. Homeowners on the Mendocino Coast build them as long-term rentals, as a place for aging parents or grown kids, or as a guest cottage that adds value to the property.

Matson General Contracting builds detached ADUs: stand-alone backyard cottages, built new from the ground up. We use the same crew and the same standards as our custom homes, starting with a properly engineered concrete foundation and finishing with the trim and cabinetry. We've been through the permit process with the City of Fort Bragg and Mendocino County many times, and we handle that paperwork for you.

ADUs are one part of what we do. You can also browse everything we build.

Fort Bragg's Pre-Approved ADU Plans

The City of Fort Bragg offers two pre-approved detached ADU designs, both craftsman-style bungalows with a front porch under the roofline:

One bedroom, 720 sq ft
Two bedrooms, 960 sq ft

Because the plans are already engineered and approved, you skip paying for a design from scratch. The roofline can face either direction to fit your lot and the sun for roof-mounted solar. You still need an engineer's site visit to confirm where the cottage will sit, Title 24 energy calculations and solar plans. The city takes a $500 deposit up front, which is credited toward your building permit fees.

We can build either plan, or a detached ADU designed around your lot if the standard plans don't fit.

What California ADU Law Allows

California has rewritten its ADU rules several times to make backyard units easier to build. Under current state law, as summarized in the 2026 ADU Handbook from the California Department of Housing and Community Development:

A permit decision within 60 days. When there's already a home on the lot, the city or county has to approve or deny a complete ADU application within 60 days.
No impact fees on smaller units. An ADU with 750 sq ft of interior living space or less is exempt from impact fees. Above that, fees are charged in proportion to the size of your main house.
Four-foot setbacks. A detached ADU only has to sit 4 feet from the side and rear property lines.
Room to build. Local rules have to allow at least 850 sq ft for a one-bedroom ADU and 1,000 sq ft for one with more bedrooms, and a detached ADU can be at least 16 feet tall. In unincorporated Mendocino County, a detached ADU can be up to 1,200 sq ft.
No owner-occupancy rule. You don't have to live on the property, so you can rent the ADU, the main house, or both.

Rules change, and every lot is different, so check with the City of Fort Bragg or Mendocino County about your parcel before you buy plans.

Built for the Mendocino Coast

Wind-driven rain, fog and salt air are hard on buildings. We detail the foundation, framing, roofing and siding of every ADU for coastal conditions, the way we've built here since 1928.

Solar. California's energy code requires solar on a newly built detached ADU (with some exceptions), and the panels can go on the ADU or the main house.
Fire sprinklers. They're required in an ADU only if your main house is required to have them, and building an ADU doesn't trigger sprinklers in the main house.

Questions about the lot itself, like setbacks, septic, utilities or the Coastal Zone, go to the City of Fort Bragg or Mendocino County Planning and Building Services. They can tell you what's allowed on your parcel.

How We Build Your ADU

From first call to move-in.

First Call

Tell us what you want to build and where. We go over the plan options, timing and how we work.

Plans & Estimate

Pick one of the city's pre-approved plans or a design for your lot, and we give you a written estimate and schedule.

Permits

We assemble and submit the permit package to the City of Fort Bragg or Mendocino County and handle their questions.

Build

Foundation, framing, roofing, utilities and finish work, managed by us through final inspection.

Compact single-story home framed and roofed by Matson General Contracting in Fort Bragg, CA

Small Homes, Built Right

A compact single-story home we built in Fort Bragg. A detached ADU goes up the same way: a solid foundation, straight framing, a tight roof and careful finish work. It's the same work we've done on the coast for four generations.

See Our Residential Work

ADU Questions

How much does it cost to build an ADU in Fort Bragg?

It depends on the size of the unit, the plan you choose, the foundation, the site work and the finishes, plus permit and plan fees. Call us at 707-202-4333 to talk through your project and get a written estimate.

How long does the permit take?

When there is already a home on the lot, state law requires the city or county to approve or deny a complete ADU application within 60 days. Mendocino County says building permits for ADUs typically take 6 to 8 weeks to approve. Lots in the Coastal Zone may also need a Coastal Development Permit. Build time depends on the size of the unit and the weather, and we'll give you a schedule with your estimate.

Can I rent out my ADU?

Yes. Under California law, a city or county cannot require you to live on the property to have an ADU, so you can rent the ADU, the main house, or both. In the Coastal Zone of unincorporated Mendocino County, the county restricts using an ADU as a vacation rental.

Do you build the City of Fort Bragg's pre-approved ADU plans?

Yes. We can build either of the city's pre-approved designs, the 720 sq ft one-bedroom or the 960 sq ft two-bedroom, or a detached ADU designed for your lot.

Do I need an architect?

Not if you use the City of Fort Bragg's pre-approved plans, since the design is already done. You still need a site plan, Title 24 energy calculations and solar plans. Mendocino County's free sample plans are unstamped, so a licensed architect has to redraw and stamp them before you can submit them.

Detached Backyard Cottages on the Mendocino Coast