Build a legal ADU in San Jose or the Bay Area with Esquives General Contractors. We handle permits, design, and full construction. Rental-ready builds.
An ADU (accessory dwelling unit) is a separate living unit on the same lot as a primary home—often called an in-law unit, granny flat, or backyard cottage. AB 68 and related California laws made it much easier to build ADUs by limiting local restrictions and speeding up approvals. Most single-family lots in cities like San Jose and Morgan Hill now have a clear path to adding an ADU, subject to size, height, and setback rules.
By law, California cities are supposed to review complete ADU applications within 60 days, but real-world timelines can vary based on plan check comments and resubmittals. In many Bay Area jurisdictions, you should plan for 2–4 months from submittal to approved permits. We help prepare a complete package up front to reduce back-and-forth and keep the schedule as tight as possible.
State law allows certain minimum setbacks—often as little as 4 feet from side and rear property lines for detached ADUs—but each city layers its own standards within those limits. Maximum ADU size usually ranges from about 800 to 1,200 square feet depending on your lot and local rules. We’ll review your specific property and local zoning to determine what’s allowed before you invest in design.
An ADU can often share water and sewer with the main house, but it depends on existing capacity and local utility requirements. Electrical can be a sub-panel off your main service if the panel has enough capacity, or we can add a new service if needed. We’ll review your current utilities, coordinate with the utility providers, and design the most cost-effective approach that meets code.
For a detached, stick-built ADU, construction usually runs 4–8 months depending on size, complexity, and site access. Garage conversions or smaller units can be faster, while larger two-story ADUs may take longer. We’ll give you a schedule based on your specific design and whether we’re dealing with grading, retaining walls, or tight access common in some Bay Area lots.
In California, your existing home’s assessed value usually stays the same, but the ADU is assessed separately as new construction. That means your property taxes will go up based on the value of the ADU portion, not a full reassessment of the entire property. For exact numbers, you’d want to talk with your county assessor or a tax professional, but we can help you understand the construction cost side.
In most Bay Area cities, you can rent out an ADU as long as you follow local regulations, such as occupancy rules and any owner-occupancy requirements if they apply. Short-term rental rules (like Airbnb) can be stricter, so it’s important to check local ordinances. We focus on building the unit to meet all code requirements so you can use it for long-term rental, family, or personal use.
A garage conversion uses the existing structure as a starting point but often still needs foundation upgrades, new framing, insulation, windows, and full MEP systems. A detached ADU is built from the ground up, usually offering more design freedom but also requiring new foundation and all-new utilities. Costs can be similar depending on the condition of the garage and local code requirements, especially for seismic and fire separation.
ADU fire sprinkler requirements in California depend on your local jurisdiction and whether the main house already has sprinklers. There are also fire separation and exterior wall rating requirements when an ADU is built close to property lines or another structure. We coordinate with your designer and the local building department to make sure the plans meet all applicable fire and life safety codes.
We design ADUs by reviewing your lot dimensions, local setback rules, existing home layout, and budget goals to identify the most feasible option first. From there, we work with you and your designer or one of our design partners to create a floor plan that uses space efficiently without unnecessary structural complexity. We advise on cost impacts of key layout choices and finish selections so the design stays aligned with your budget throughout.
ADUs go through the same inspection stages as a small home: foundation, underground utilities, framing, rough plumbing/electrical/HVAC, insulation, drywall, and final inspection, among others. Some jurisdictions may have additional inspections for energy compliance or fire safety. We coordinate all inspections and make sure each stage is ready so the project keeps moving.
You should bring a contractor into the ADU conversation as early as possible, ideally while you’re still exploring layouts and size. That allows us to provide realistic cost input, flag tricky site issues like drainage or access, and prevent you from spending money on a design that’s too expensive to build. We can work with your chosen designer or connect you with design partners used to California ADU rules.
Esquives General Contractors · Morgan Hill, CA · (408) 809-1212 · sales@esquivescontractors.com · Mon–Fri 6:00am–5:00pm, Sat 6:00am–2:00pm · CSLB License #1056641 · Licensed, bonded & insured.