A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Los Alamitos, CA
Adding an ADU in Los Alamitos usually runs between $180,000 and $420,000 for a detached one-bedroom unit, with most homeowners landing around $250,000 to $350,000 once site work, utility hookups, and finishes are included. What makes Los Alamitos different from nearby Orange County cities is the mix of 1950s-to-1970s single-story ranch homes on flat, compact lots, plus a city permitting office that reviews ADU plans for compliance with both state law and local design standards. If you’re weighing a backyard unit, a garage conversion, or a full second story, call us at (903) 568-7222 for a written price before any work starts.
Why Los Alamitos Homes Are Different
Los Alamitos sits on flat terrain with soil that drains well in most neighborhoods, which keeps foundation work simpler than hillside builds in Seal Beach or Rossmoor. The housing stock skews toward post-war single-story homes with detached garages, and many lots in the older tracts off Katella Avenue and Los Alamitos Boulevard are between 5,000 and 7,000 square feet. That lot size matters for ADUs because the city requires specific rear and side setbacks, and a narrow or shallow lot can push you toward a JADU (a converted garage or attached unit) instead of a detached prefab module. We see this in the neighborhoods around Oak Middle School and near the Joint Forces Training Base, where garage conversions make up a large share of our ADU work in Los Alamitos.
Roof lines also drive a lot of decisions here. Most original homes have low-pitch or flat sections with shallow eaves, so tying a new addition into the existing structure means matching fascia heights and roof materials rather than just framing a box off the back. Clay tile and composition shingle are both common, and matching either one changes the look of the finished roofline. On the permitting side, Los Alamitos follows state ADU law closely, which speeds up the basic approval path, but HOA-governed pockets and properties near the base can add their own architectural review steps. We handle that paperwork as part of the written scope we give you before we start.
Our Main Los Alamitos Services
The two conversations Los Alamitos homeowners start with us most are building a detached ADU for rental income or adding square footage to a home they plan to keep for another 20 years. Here’s what each one looks like on the ground.
ADU Builders in Los Alamitos
Most Los Alamitos ADU projects fall into one of three paths: a detached backyard unit, a garage conversion (JADU), or an attached wing with its own entrance. Because many lots here are rectangular and flat, a prefab panel system from Abodu or Cover can go from permit to dry-in much faster than a fully site-built frame, which matters when you’re carrying a construction loan. We walk you through setback rules, utility trenching, and whether your existing garage slab can support a conversion before we ever quote a number. ADU Builders in Los Alamitos
Home Addition Contractor in Los Alamitos
A home addition in Los Alamitos often means extending the back of a ranch home for a larger kitchen or a new primary suite, and the biggest variable is how the existing roofline ties in. We match the original fascia height and roof material so the addition doesn’t read like a box bolted onto the house. Foundation work on these flat lots is usually straightforward, but older homes sometimes have outdated footings that need reinforcement to meet current code in Los Alamitos. Home Addition Contractor in Los Alamitos
Room Addition Contractor in Los Alamitos
A single room addition, like an office or a fourth bedroom, runs leaner than a full home addition and often fits within the existing lot lines without needing a variance. On the smaller lots near the civic center, we typically design the room to tuck into a side yard, using a slab-on-grade foundation that keeps costs down. The work includes matching stucco or siding, tying into the HVAC system, and aligning the new roofline with what’s already there. Room Addition Contractor in Los Alamitos
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 Los Alamitos
We build with a short list of prefab and materials brands that Los Alamitos homeowners can research and verify on their own: Abodu, Cover, Dvele, and James Hardie cladding. Panels and materials are sourced regionally, and most popular options are quoted with clear lead times. See our brands for the full list.
Pricing for ADU Company in Los Alamitos, CA
| Service | Typical range in Los Alamitos |
|---|---|
| Detached 1-bedroom ADU (prefab panel) | $180,000 – $280,000 |
| Detached 1-bedroom ADU (site-built) | $220,000 – $340,000 |
| Detached 2-bedroom ADU | $280,000 – $420,000 |
| Garage conversion (JADU) | $110,000 – $180,000 |
| Attached ADU (single story) | $150,000 – $260,000 |
| Home addition (primary suite, 300 – 500 sq ft) | $150,000 – $280,000 |
| Home addition (kitchen extension, 200 – 350 sq ft) | $120,000 – $220,000 |
| Room addition (office/bedroom, 150 – 300 sq ft) | $80,000 – $160,000 |
| Foundation work (new slab or footing repair) | $8,000 – $25,000 |
| Utility trenching and hookups | $5,000 – $18,000 |
Prices in Los Alamitos push toward the higher end when a lot needs extra foundation work, when HOA review adds time and revisions, or when you choose site-built framing over a prefab panel system like Cover or Dvele. Every quote we give is a written, line-item price before work starts, so the number you approve is the number you pay.
Neighborhoods We Serve in Los Alamitos
We work across Los Alamitos, including the older tracts around Katella, the streets near the Joint Forces Training Base, the area by Oak Middle School, and the neighborhoods along Los Alamitos Boulevard. Most of the city is reachable from our scheduling hub in under 30 minutes.
- Old Town Los Alamitos
- Neighborhoods near Oak Middle School
- Areas around the Joint Forces Training Base
- Homes along Katella Avenue and Los Alamitos Boulevard
- South side near Cerritos Avenue
Service Area – Cities Near Los Alamitos
Beyond Los Alamitos, our crews regularly work in the surrounding communities. We serve homeowners in Cypress, CA, Hawaiian Gardens, CA, Seal Beach, CA, and La Palma, CA. Scheduling is coordinated from our Los Angeles office, with local crews dispatched to each city.
Serving Los Alamitos, CA - Our Local Coverage Area
We’re based in the Los Alamitos 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 Los Alamitos
Once we complete the site walk, survey, and design review, most Los Alamitos projects are ready for permit submittal within four to eight weeks, depending on whether HOA review is involved and which prefab brand you choose. From there, city review times vary. Call (903) 568-7222 for a timeline specific to your lot.
If your home is in an HOA-governed neighborhood, yes, the HOA may require an architectural review before the city approves the permit. Los Alamitos follows state ADU law, which limits how much an HOA can block a project, but the review step still adds time and paperwork. We handle that as part of your written scope.
If anything we built isn’t done right within a full year, we return and make it right, in writing, at no charge. It’s stamped on every project, along with a free second visit if any covered repair fails. Call (903) 568-7222 for a free estimate and we’ll walk you through the exact terms before you sign anything.
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 Los Alamitos Customers Say
"Booked a consult online and met the project manager two days later. Weekly progress updates arrived by text with photos. ADU finished on schedule."
- Hannah W."Clean, quiet crew. They respected the neighbors, kept noise to working hours, and swept the driveway every evening."
- Hope C."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N.
