--- title: "ADU Construction in Nevada City, CA | TDI®" description: "ADU builder in Nevada City, CA: detached and attached ADUs, garage conversions and junior ADUs. Permits handled, free estimates. Call (530) 349-8997." url: https://www.tdiusa.com/service-areas/nevada-city-ca/adu-construction/ --- ![TDI® crew framing the interior of an accessory dwelling unit in Sacramento](https://www.tdiusa.com/images/services/general-contractor.webp) Nevada City, CA · ADU Construction # ADU Construction in Nevada City ADU builder in Nevada City, CA: detached and attached ADUs, garage conversions and junior ADUs. Permits handled, free estimates. Call (530) 349-8997. [📞 Call (530) 349-8997](tel:+15303498997) [All Services in Nevada City](https://www.tdiusa.com/service-areas/nevada-city-ca/) Our technicians serve Nevada City and are typically on-site within 60 minutes of your call. An accessory dwelling unit (ADU) adds a complete, permitted living space on the lot you already own: room for aging parents or grown kids, a home office, or rental income that helps cover the mortgage. TDI® builds ADUs in Nevada City and across Nevada County, and manages each project from the first site review to the final inspection under one contract. ## ADUs we build in Nevada City - **Detached ADUs**, a standalone backyard cottage with its own foundation, kitchen, bathroom and entrance - **Attached ADUs**, a new unit built onto the existing home with its own entrance - **Garage conversions**, turning an attached or detached garage into a full living unit - **Junior ADUs**, up to 500 square feet carved out of existing space inside the home, with an efficiency kitchen and a separate entrance - **Above-garage units**, where the lot and local rules allow it ## Building an ADU in Nevada City Nevada City is the Nevada County seat, known for its Gold Rush-era downtown, historic homes and foothill properties on sloped, wooded lots. Sloped lots are common in Nevada City, so the first question is where a unit can sit without a costly foundation. A garage conversion or an attached ADU often avoids major grading, while a detached unit on a slope may need a stepped or engineered foundation. Wildfire-area building standards for siding, vents, decks and roofing apply in many foothill locations, and we design to them from the start. Older homes often need an electrical service upgrade to carry a second unit, and sewer and water lines may need to be replaced or upsized for the new connection. We check the panel, the sewer lateral and the water service early so those costs are in the estimate, not a surprise during construction. Foothill properties see hot summers, more winter rain than the valley floor, occasional snow at higher elevations, and wildfire-area building rules for exteriors. We design ADUs to California Title 24 energy standards, with insulation, window placement and a properly sized heating and cooling system so the unit stays comfortable year round. ## How an ADU project works with TDI® 1. **Site and zoning review.** We look at your lot, setbacks, utilities and access before anything is drawn, so the design fits what can be permitted. 2. **Design and drawings.** We coordinate floor plans and construction drawings sized to your goals and budget. 3. **Permits and plan check.** We submit the application to the City of Nevada City building department (or Nevada County for properties outside city limits), answer plan check comments and track the permit through approval. 4. **Construction.** Foundation, framing, roofing, plumbing, electrical and HVAC, insulation to Title 24, then drywall, cabinets, fixtures, flooring and finishes. 5. **Final inspection and walkthrough.** We close the permit and walk the finished unit with you, so you have a legal, insurable, rentable space. ## Licensed and accountable - **CSLB licensed general contractor**, License #1041773, Class B General Building - **Native American owned (Cherokee)** and a certified Minority Business Enterprise - **Building in Northern California since 1983** Thinking about an ADU in Nevada City? Call us for a site review and a free written estimate. Serving Nevada City — ★ 5.0 · 9 Google reviews > “Thank you Alex for answering my questions.” — Marie, May 2026 Coverage ## ADU Construction in Nevada City: Service Coverage TDI® Serving Nevada City and the surrounding area ★★★★★ 5.0 · 9 Google reviews 701 Del Paso Road Suite 200, Sacramento, CA 95834 [(916) 259-7848](tel:+19162597848) 24/7 [📞 Call Now](tel:+19162597848) [Get Directions](https://www.google.com/maps/dir/?api=1&destination=701%20Del%20Paso%20Road%20Suite%20200%2C%20Sacramento%2C%20CA%2095834) ## Frequently Asked Questions How fast can you arrive for adu construction in Nevada City? We offer 24/7 emergency response and typically arrive on-site in Nevada City, CA within about 60 minutes of your call — often sooner for active water, fire, or storm damage. Can I build an ADU on my property in Nevada City? In most cases, yes. California law allows an ADU on lots with a single-family or multifamily home, and many single-family lots can have both a detached or attached ADU and a junior ADU inside the existing house. Projects in Nevada City are permitted through the City of Nevada City building department (or Nevada County for properties outside city limits), and local rules still control details like height, setbacks and utility connections, so we start with a site and zoning review before any drawings are made. How big can an ADU be? Under state law, a junior ADU can be up to 500 square feet and is built within the existing home. Attached and detached ADUs are generally allowed up to 1,200 square feet, though local limits and lot conditions can affect the final size. Units of 750 square feet or less avoid most impact fees, which is why many owners design right at or under that size. Is a garage conversion cheaper than a new detached ADU? Usually. A garage conversion reuses the existing foundation, walls and roof, so the work focuses on the floor, insulation, windows, a kitchen, a bathroom and utilities. A detached ADU needs its own foundation, framing, roof and utility runs. The right choice depends on the garage's condition, your parking needs and how much living space you want. How long does an ADU take to build in Nevada City? Design and permitting often take two to four months, and California requires local agencies to act on a complete ADU application within 60 days. Construction typically runs two to four months for a garage conversion or junior ADU, and four to eight months for a new detached unit. Is TDI® licensed and insured? Yes. TDI® is a CSLB licensed general contractor (#1041773, Class B General Building), insured for residential and commercial work, and has been building in Northern California since 1983. Will my homeowners insurance cover adu construction in Nevada City? Often, yes — most homeowners policies cover sudden and accidental damage, though coverage always depends on your specific policy and the cause of the loss. We work with all major insurance carriers, bill them directly, and document the damage with photos and moisture readings so your Nevada City adjuster has everything needed to process the claim. ## ADU Construction response in Nevada City Most Nevada City calls see a technician on-site within 60 minutes of your call. [Call (530) 349-8997](tel:+15303498997) [Get a Free Estimate](https://www.tdiusa.com/contact/#estimate) More Coverage ## Nearby & Related - [Contact TDI®](https://www.tdiusa.com/contact/) - [ADU Construction in Sacramento](https://www.tdiusa.com/services/adu-construction/) - [General Contractor Serving Nevada City](https://www.tdiusa.com/service-areas/nevada-city-ca/) - [Garage Construction in Nevada City](https://www.tdiusa.com/service-areas/nevada-city-ca/garage-construction/) - [Room Additions and Home Additions in Nevada City](https://www.tdiusa.com/service-areas/nevada-city-ca/room-addition/) - [ADU Construction in Grass Valley](https://www.tdiusa.com/service-areas/grass-valley-ca/adu-construction/)