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Get your free estimateADU Company in Milpitas, CA
An ADU (accessory dwelling unit) is a self-contained living space – think a small house with its own kitchen, bath, and entrance – built on a lot you already own. In Milpitas, that usually means a detached backyard unit on a ranch-home lot from the 1960s or 70s, or a garage converted into a compact rental. The homes here were built for single families on generous lots, which makes Milpitas one of the easier South Bay cities for adding a second unit without fighting for space. We’re Lodgewick ADU Builders, the ADU company of the Kingswell family, and we put every price, window, and warranty commitment in writing before work starts. Call (669) 266-4319 to talk about your lot.
Why Milpitas Homes Are Different

Milpitas housing stock runs heavily to single-story ranch and split-level homes built between 1955 and 1985, sitting on 6,000 to 8,000 square foot lots. That’s good news for ADU work: the rear setbacks are deep enough to hold an 800 to 1,200 square foot detached unit, and most attached garages are wide and flat enough to convert into a JADU (junior accessory dwelling unit) without structural gymnastics. But there are quirks specific to Milpitas that show up on nearly every job.
The first is drainage. Many Milpitas backyards slope gently toward creeks or the old salt-pond flats near the bay, which means foundations often need imported fill and added drainage. Contractors who work Milpitas regularly budget for extra grading and, on lower lots, a sump pump. The second is climate. Summers are dry and warm, but heat waves do land. We design ADUs to maximize cross-ventilation and typically spec a mini-split heat pump, which handles both cooling and heating without adding ductwork. And because Milpitas enforces the Water Efficient Landscape Ordinance, we plan drought-tolerant plantings around the new unit from day one, not as an afterthought when the inspector asks.
One more thing: homeowners near Great Mall or the BART station are sitting on rental gold. Tech commuters priced out of Santa Clara regularly rent ADUs here, and a well-built detached unit with its own entrance and parking pad commands strong monthly rent. That income math is why so many Milpitas owners choose a backyard ADU over a garage conversion when the lot allows it.
Our Main Milpitas Services
Most Milpitas homeowners call us about one of three projects: adding square footage to the main house, converting an attached garage, or building a detached backyard ADU. Each has its own page with local pricing and process details.
Home Addition Contractor in Milpitas
Home additions in Milpitas usually extend off the back of a ranch home, where the lot is long and the roofline is simple. The work often involves matching 1960s or 70s framing, tying into existing slab foundations, and upgrading the electrical panel, which many older Milpitas homes never got around to replacing. Because additions change the footprint rather than adding a separate unit, the permitting conversation with the City of Milpitas is different from an ADU project, and we handle that paperwork end to end. Russ Delmar leads our home addition work in Milpitas. Get the full breakdown on our Home Addition Contractor in Milpitas page.

Garage Conversion Contractor in Milpitas
A garage conversion in Milpitas turns an attached or detached garage into a JADU or full ADU with a kitchenette, bath, and separate entrance. The big Milpitas-specific consideration is that many older garages were built on slabs with no moisture barrier, so we test for vapor and add a barrier before flooring goes in. Shallow sewer laterals are common here, which can affect where the bathroom goes. You can read the local cost range and permitting path on our Garage Conversion Contractor in Milpitas page.

ADU Builders in Milpitas
Detached ADUs are the most popular route in Milpitas because the lots support them. A 1965 ranch with a deep rear yard can usually hold a 1,000 square foot two-bedroom unit and still leave room for a patio. We handle site prep, foundation with proper grading for those sloping Milpitas yards, utility runs, and the full build. We also work regularly with prefab ADU manufacturers when the lot and budget suit factory-built construction over stick-built. Full local pricing is on our ADU Builders in Milpitas page.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Milpitas
We spec and install materials from our brands that hold up in Milpitas’s dry summers and occasional heat waves. That includes James Hardie siding for fire-resistant exteriors, plus prefab ADU systems from Abodu, Cover, and Dvele when a homeowner wants a faster path from permit to move-in.
Pricing for ADU Company in Milpitas, CA
| Service | Typical range in Milpitas |
|---|---|
| Detached ADU, 1 bed / 1 bath (site-built) | $180,000 – $280,000 |
| Detached ADU, 2 bed / 1 bath (site-built) | $250,000 – $380,000 |
| Prefab ADU (Abodu, Cover, or Dvele) | $225,000 – $350,000 installed |
| Garage conversion to JADU | $90,000 – $160,000 |
| Garage conversion to full ADU | $140,000 – $220,000 |
| Home addition, 200 – 400 sq ft | $120,000 – $220,000 |
| Home addition, 400 – 600 sq ft | $200,000 – $340,000 |
| Foundation work (fill, grading, drainage, sump) | $15,000 – $45,000 |
| Mini-split heat pump install for ADU | $8,000 – $16,000 |
| Electrical panel upgrade (common on 1960s – 70s homes) | $3,500 – $6,500 |
What pushes Milpitas pricing upward is typically the site work: imported fill on sloped yards, added drainage, and sometimes a sump pump for lots near the old salt-pond flats. Prefab ADUs can save two to three months on the timeline, but the foundation and utility costs stay roughly the same. Whatever the final number, you get a written price before work begins, on every project, no exceptions. Call (669) 266-4319 for a free estimate on your specific lot.
Neighborhoods We Serve in Milpitas
We work across Milpitas, from the 1960s ranch tract near the Great Mall to the hillside lots above Calaveras Boulevard. Most crews can reach any Milpitas neighborhood same week for an estimate.
- Central Milpitas near Great Mall and BART
- Milpitas Hills above Calaveras Boulevard
- Sunnyhills neighborhood and surrounding tracts
- South Milpitas near the county line
- East Milpitas toward the foothills
Service Area – Cities Near Milpitas
Our Milpitas crews also cover nearby South and East Bay cities. For work in San Jose, CA, Santa Clara, CA, Fremont, CA, or Los Altos, CA, scheduling is coordinated from the brand’s San Francisco Bay Area office, with local crews dispatched to each city.
Serving Milpitas, CA - Our Local Coverage Area
We’re based in the Milpitas area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Company in Milpitas

Most Milpitas addresses can be seen within the same week, and we arrive in a defined window that we give you in writing. No open-ended “sometime between 8 and 5.” Call (669) 266-4319 to schedule a free estimate.
If your Milpitas neighborhood has an HOA, the HOA may have its own review on top of city permitting, even though California law limits how much an HOA can restrict ADUs. We walk you through both approval tracks before work starts. Call (669) 266-4319 and we’ll tell you what applies to your specific street.
No. The Kingswell Guarantee means a written price before work begins, with no price changes at the door. If site conditions force a change in scope, you see it in writing and approve it first. Call (669) 266-4319 for a free estimate and a written quote.
Want to talk through your Milpitas lot? Call (669) 266-4319 or visit our home page to see how the Kingswell family has built a different kind of ADU company since 2010.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Milpitas Customers Say
"Converted our garage into a rental studio. The crew was respectful of the neighbors and kept the site clean. It's bringing in rent now and paid for itself faster than I expected."
- Grace Yoon"Built a backyard unit for my mother in law. They handled the permits, gave me a real timeline, and stuck to it within a few days. The written price is what we paid, which anyone who's done construction knows is rare."
- Dennis Fairchild"Added a suite for my dad. They walked us through every cost before a hammer swung and stuck to it. The written price is what we paid, no change orders."
- Ingrid Salazar





