Golden State ADUs is a full-service design-build Accessory Dwelling Unit (ADU) specialist serving Davis homeowners from our Roseville office. If you’re looking for an ADU builder in Davis who handles architectural design, structural and civil engineering, permitting and construction with one accountable team, that’s what we do, and ADUs are all we do. We’re licensed and bonded (LIS. #1125656), trusted by 100+ happy customers, and every project carries a 10-year structural integrity warranty plus a 1-year fit-and-finish warranty.
Inside city limits, your ADU building permit comes from the City of Davis Community Development and Sustainability Department, Building Division, at 23 Russell Boulevard, Suite 2. Not Yolo County. Davis also adopted Ordinance No. 2693 on September 1, 2026, updating its ADU regulations, with a calculated effective date of October 1, 2026. We design to the local rules that apply today.
Book a free 1-hour project walkthrough and start with clarity instead of guesswork.
Our Accessory Dwelling Unit (ADU) Construction Services in Davis
Every service below is handled in-house. Architectural design, structural and civil engineering through our partner firm Golden State Design & Engineering, permitting, and construction all sit with one team, so you’re never coordinating an architect, an engineer and a general contractor on three different schedules. See our full ADU services.
Detached ADUs and Custom Design
A detached ADU is a secondary housing unit set apart from your main living space, with its own kitchen, bathroom, living area and own entrance. In Davis, detached ADUs subject to local standards can reach 850 square feet with zero or one bedroom, and 1,000 square feet with two or more bedrooms. Those size limitations shape the floor plan more than anything else. We design studios through three-bedroom layouts around your design goals, shaped to your lot rather than dropped onto it. ADUs can also be attached to the primary residence where the site favors it.
Garage Conversion and Attached ADU Options
Garage conversions are one of the most practical ADU paths in Davis, where the 1970s and 1990s were the city’s largest housing construction decades, and the basic structure is already standing. Before we price a conversion, we check the existing garage framing, electrical capacity, sewer routing and any prior unpermitted work. Davis warns that an ADU may require a larger sewer lateral, a larger electrical panel or photovoltaic solar, so utilities get verified early. Conversions of existing space, including an existing basement where one is present, generally move faster than ground-up construction, and basement apartments follow the same permitting path.
Permitting and Compliance, Done for You
We prepare the scaled site plan, submit to the Davis Building Division, respond to corrections and carry the ADU through inspections. We verify that your project complies with state ADU law, Davis zoning laws and current local standards before plans are finalized, which is where most bureaucratic delays actually begin. You sign where needed. We handle the rest of the code and paperwork.
Interior Design Bundles and Material Coordination
Our interior design bundles cover curated layouts, finish selections and material ordering, coordinated in-house so you manage no separate vendors. Because Davis summers are hot and dry, we plan window placement, shading and orientation for natural light and better energy performance without turning the ADU into a heat trap. Smart layout also makes a small space live far larger than its plan suggests. Construction quality is held to the approved plans and adopted local building codes at every stage.
Why Davis Homeowners Choose Golden State ADUs
ADUs are our specialty, not one line on a remodeling menu, and one team stays accountable from concept to certificate of occupancy. Choosing the right ADU builder matters more in Davis than most places, because the variables here (trees, utilities, a freshly updated ordinance) tend to surface after a homeowner has already fallen in love with a floor plan.
“Will it go over budget?” We give you a written, itemized estimate with allowances, exclusions and assumptions spelled out, plus value engineering options where they make sense. No low teaser figure that quietly grows. A good builder tells you what a project will cost before you’re emotionally invested, not after. Costs vary based on several factors, and the honest drivers in Davis are worth hearing early:
- Tree protection review and any required mitigation
- A larger sewer lateral, a larger electrical panel or photovoltaic solar, all of which the city flags as possible ADU requirements
- Site preparation, access and utility routing
- Size: Davis exempts ADUs below 750 square feet of interior livable space from development impact fees
- Materials and finish level
- Permit fees, which the city does not publish as one standard ADU price, directing applicants to the Building Division for project-specific amounts
“Will permitting be a nightmare?” Not yours. We know which office issues the permit, what Ordinance No. 2693 changed, and how to answer plan-check corrections quickly instead of losing weeks to a round trip.
“Will it actually get built?” We’re licensed and bonded under LIS. #1125656, which gives you the protections that come with hiring a licensed California builder. Responsiveness and personalized service are named standards here: we answer calls and emails and send regular project updates without you chasing them. Our portfolio spans detached units, garage-adjacent builds and compact studios, and we’re glad to walk you through completed projects and client references before you commit.
An ADU built well adds real property value and gives you flexible options later: a rental unit that helps offset mortgage payments, extra living space for family members, or a quiet base for remote work and a small business. Many homeowners plan to generate rental income and end up using the space for multi-generational living instead. See what 100+ homeowners already decided.
How Your Davis ADU Project Works: Our 5-Step Process
- 1. Initial consultation and site walkthrough. A free 1-hour meeting at your property, where we assess setbacks, trees, easements, utilities, access and what you actually want the unit to do, whether that’s income, private space for a parent or a workshop.
- 2. Feasibility and budget analysis. We tell you what fits, what it will realistically cost and which conditions on your site drive the number up. If your yard won’t support the ADU you want, you’ll hear that from us.
- 3. Custom design and engineering. Architectural, structural and civil work happens in-house. Design and permit plans typically take 3 to 5 months, collaborative and iterative, with your input at each stage.
- 4. Permit submittal and city review. We file with the Davis Building Division at 23 Russell Boulevard and manage corrections. The city publishes a general building-permit processing period of 20 to 35 business days from submission, though corrections extend it.
- 5. Construction and final inspection. Once construction begins, it typically runs 3 to 4 months, built to the approved plans and local codes, with regular updates and your warranty coverage in hand at handoff.
All timelines are typical, not guaranteed. We’d rather give you a schedule that holds than one that sounds good in a sales meeting.
What Building ADUs in Davis Actually Involves: Local Knowledge That Changes the Plan
Trees come first. In Davis, private trees that otherwise would not be protected become protected the moment a permit is pulled on the property, and that explicitly includes an ADU permit. This can reshape your buildable footprint before a single line is drawn. We review tree locations and driplines during feasibility, well before your project begins on site.
Current code, not last year’s. Ordinance No. 2693 governs new Davis ADUs as of its October 1, 2026 effective date. Under the current ordinance, new ADUs generally require four-foot side and rear setbacks, and a detached ADU subject to local standards generally must sit five feet from the primary dwelling, unless that separation would preclude an otherwise qualifying 800-square-foot ADU. Davis does not require an additional vehicle parking space for an ADU. The number of ADUs allowed on a given parcel depends on current state and local standards, which we confirm lot by lot. Height, coverage and siting decisions all key off these rules, and older online guidance may be stale.
Free city plans versus custom design. Davis offers free pre-designed ADU plans in three sizes (a 300-square-foot studio, a 565-square-foot one-bedroom and a 740-square-foot two-bedroom) in Adobe, Agrarian and Mid-Mod styles. They’ve already been plan-checked, which is a real advantage. The catch: the city does not permit applicants to modify those plans before the approved structure is complete, and you still need a site plan, project review and a building permit. When your lot geometry, your family’s unique needs or your home’s roofline call for something else, custom design is the better route. We’ll compare both honestly with you.
Neighborhoods and housing stock. Old North, Old East and University Avenue/Rice Lane are the traditional residential neighborhoods Davis identifies around its historic core, and they carry design considerations that a backyard build has to respect. The city’s Old East historic study documents Victorian, Eastlake, Four Square/Colonial Revival, Craftsman and bungalow homes around I, J, K and Third streets, so an ADU there needs an architectural vocabulary that complements the main house. Covell Park, developing north of Covell Boulevard by the late 1960s, has homes bordering a greenbelt network, where access, easements and root zones get checked parcel by parcel. South Davis skews later: most of it was still farmland in 1968. Our Roseville-based team serves Davis as part of our broader Northern California service area, planning site visits, inspections and construction management around the I-80 corridor and your project’s schedule.
Frequently Asked Questions
Do I need a permit to build an ADU in Davis?
Yes. Every ADU in Davis requires a building permit, issued by the City of Davis Community Development and Sustainability Department, Building Division, at 23 Russell Boulevard, Suite 2. If your property is inside city limits, that’s a City of Davis permit, not a Yolo County one. We handle the zoning review, submittal and inspections for you.
How much does it cost to build a 1,000 sq ft ADU in Davis?
Cost varies by site, square footage and scope, so we quote after feasibility rather than from a per-foot teaser figure. The real variables are tree protection, sewer lateral work, electrical panel capacity, photovoltaic solar, site work and finish level. Size matters too: ADUs below 750 square feet of interior livable space are exempt from Davis development impact fees, and the city doesn’t publish one standard permit price, directing applicants to the Building Division for project-specific fees. Our online ADU cost estimator is a useful starting point, not a quote.
How long does Davis take to approve ADU plans?
The City of Davis publishes a general building-permit processing period of 20 to 35 business days from submission. That’s city review only. Across the whole project, design and permit plans typically run 3 to 5 months and construction typically runs 3 to 4 months. All of it is typical rather than guaranteed, and plan-check corrections extend the schedule.
Does Davis require a tree permit before I build an ADU?
It can. Private trees that would otherwise be unprotected become protected when a permit is pulled on your property, including an ADU permit, and Davis currently states a $150 fee for a city or private/protected tree-permit application. We review tree ownership and driplines during feasibility so the ADU footprint is set around them rather than against them.
Can an ADU support multigenerational living?
Yes, and it’s one of the most common reasons Davis families call us. In-law suites and granny flats describe the same core idea: a self-contained living space a few steps from the main house. Aging parents stay close, adult children get real independence, and the same unit later serves as guest suites or a home office. That makes an ADU a versatile addition as your home life changes.
What’s the most cost-effective way to build an ADU?
Converting existing space, such as a garage, or building a compact footprint under 750 square feet usually carries the fewest ADU construction cost drivers, since that size is exempt from Davis development impact fees. We also apply value engineering during design, trading where it doesn’t show and holding quality where it does. And we’ll compare your options against the city’s free 300, 565 and 740-square-foot plan sets rather than pretending they don’t exist.
Do you serve my part of Davis?
Yes. We serve Davis and the surrounding Northern California region from our Roseville office, including Old North, Old East, Central, North and South Davis, along with the Woodland-adjacent and I-80 corridor communities.
Book Your Initial Consultation and See What Your Davis Property Can Do
One partner, from the first sketch to the certificate of occupancy, backed by a 10-year structural integrity warranty and a 1-year fit-and-finish warranty. Step one costs you nothing: a free 1-hour project walkthrough where you leave with feasibility insight, a realistic budget conversation and clarity on the Davis rules that took effect October 1, 2026, whether or not you hire us.
There’s a good reason to start now. Tree and utility conditions are far cheaper to identify before a footprint is set than after. And the right ADU can hold aging parents close, house a working adult child, or become the home office your main house never had room for.
Call us at (916) 909-2387, email office@gsadus.com, or visit our office at 1001 Enterprise Way #100 in Roseville. Book a consultation and get a free estimate for your Davis ADU.
