A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Martinez, CA
An ADU in Martinez, CA typically costs $180,000 to $420,000 depending on whether you convert an existing garage, build a detached backyard cottage, or add onto the main house. The older housing stock here, with its roomy lots and detached garages, makes Martinez one of the stronger East Bay cities for ADU potential. Lodgewick ADU Builders handles accessory dwelling units (a second, fully independent home on your existing property), garage conversions, and home additions with a written price before any work begins. Call (707) 760-0502 to talk through your lot.
Why Martinez Homes Are Different
Much of Martinez’s housing dates from the early to mid 20th century, which means single-family homes on larger lots with detached garages and generous backyards. That’s the sweet spot for ADU work. The common construction is wood frame with stucco or siding, which generally offers flexibility for tying new framing into existing walls. But homes built before the 1960s, particularly on the hillsides above downtown, often have undersized footings and old slab-on-grade garage floors. A garage conversion on one of those lots frequently starts with structural upgrades before the livable space can be framed, and that’s a line item a contractor needs to flag early.
Martinez also has a Mediterranean climate: hot, dry summers and mild, wet winters. An ADU here needs real insulation and proper ventilation, not the minimum. Winter rains put a premium on drainage and foundation waterproofing, especially on sloped lots where runoff collects against the new structure. These aren’t optional upgrades in Martinez; they’re the difference between a unit that stays comfortable year round and one that bakes in August and smells musty by February.
Our Main Martinez Services
Homeowners in Martinez call us most often about three things: adding square footage to the main house, converting a detached garage into a rental or in-law unit, and building a new ADU from the ground up. Each has its own dedicated page with pricing and local specifics.
Home Addition Contractor in Martinez
Home additions in Martinez often mean expanding into a backyard that is deeper than it is wide, or bumping out a kitchen on a mid-century ranch. The permitting path runs through the City of Martinez, and hillside lots can trigger geotechnical review. Our team handles the structural work, the foundation, the roofline tie-in, and the interior finish as one scope with one written price. Home Addition Contractor in Martinez covers what a typical addition costs here and how we sequence the job around your family living in the house during construction.
Garage Conversion Contractor in Martinez
A garage conversion in Martinez usually starts with a detached garage built between the 1920s and 1960s. Many of those structures were never permitted for habitation and sit on thin slabs with shallow footings. That means engineered plans, new footings, and often a full re-frame of the walls before insulation and drywall go in. The upside is that the footprint already exists, which keeps the per-square-foot cost below new construction in most cases. Garage Conversion Contractor in Martinez details the structural and permitting realities specific to this city.
ADU Builders in Martinez
New detached ADUs in Martinez work well on the large lots found in neighborhoods like Virginia Hills, Mountain View, and the tree streets east of downtown. We walk the site, check the soils and the setback requirements, and help you choose between stick-built and prefab systems from Abodu or Cover when the lot suits them. Every build gets a written guarantee before we start. ADU Builders in Martinez has full pricing, process, and timeline detail.
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 Martinez
We work regularly with Abodu, Cover, James Hardie, and Tuff Shed products in Martinez. Prefab shells from Abodu and Cover fit many flat and gently sloped lots here, and Hardie siding holds up well to the dry summer heat. Visit our brands page for the full list and what we stock locally.
Pricing for ADU Company in Martinez, CA
| Service | Typical range in Martinez |
|---|---|
| Detached ADU (1 bed, 1 bath, 500 – 600 sq ft) | $180,000 – $260,000 |
| Detached ADU (2 bed, 2 bath, 700 – 1,000 sq ft) | $250,000 – $400,000 |
| Garage conversion to ADU (400 – 600 sq ft) | $120,000 – $200,000 |
| Garage conversion, hillside lot with structural upgrades | $160,000 – $240,000 |
| JADU (500 sq ft or less, attached) | $90,000 – $150,000 |
| Home addition (300 – 500 sq ft) | $120,000 – $220,000 |
| Home addition with kitchen or bath rough-in | $150,000 – $260,000 |
| Foundation replacement under existing garage | $25,000 – $60,000 |
| Utility trenching and new service panel | $8,000 – $20,000 |
Prices in Martinez trend higher when the lot slopes, the garage predates 1960 and needs new footings, or the existing panel can’t carry the new load. Every project gets a written price before we start, and that number doesn’t change at the door.
Neighborhoods We Serve in Martinez
We work across Martinez, from the flats near downtown to the hillside streets with bay views. Crews are typically in the area two to three days a week, so scheduling a walk-through is usually quick.
- Virginia Hills
- Mountain View
- Downtown Martinez
- The tree streets east of downtown
- Alhambra Valley area
Service Area – Cities Near Martinez
We also serve homeowners in nearby East Bay communities, including Orinda, CA, Moraga, CA, Richmond, CA, and Emeryville, CA. Each city has its own permitting quirks and lot patterns, and our estimators know them well enough to flag potential issues on a first walk-through.
Serving Martinez, CA - Our Local Coverage Area
We’re based in the Martinez 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 Martinez
Site visits for Martinez homeowners are usually scheduled within a week. Permitting through the City of Martinez typically takes two to four months depending on plan review volume and whether a hillside geotechnical report is required. Call (707) 760-0502 to get on the schedule and see where your project fits.
Most Martinez neighborhoods do not have HOAs, but a few hillside communities do. If your property falls within one, we review the HOA’s architectural guidelines as part of the pre-construction walk-through and flag any restrictions before you pay for plans.
No. The price is written before work begins, and it does not change at the door. If we uncover an unknown condition during construction, Russ Delmar sits down with you and puts any adjustment in writing before proceeding. The 365-Day Done Right Promise covers the workmanship after the job is finished: if something is not right, we come back and make it right, free.
Call Lodgewick ADU Builders at (707) 760-0502 for a free estimate on your Martinez ADU, garage conversion, or home addition. A live person answers, every time.
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 Martinez Customers Say
"The ADU came out beautiful and the permitting, which terrified me, was handled start to finish. They kept me updated every week so I was never wondering what was happening."
- Shauna Mills"Turned our detached garage into a little guest house. Clean crew, respectful of the neighbors, and no mystery charges at the end. Love how it turned out."
- Carmela Fontes"I was nervous about adding on but they walked me through every step and every cost before we started. No surprise change orders halfway through like I'd heard horror stories about."
- Eleanor Pratt
