A new rear addition with a vaulted beamed ceiling and tall windows
Room Addition Contractor · Los Alamitos, CA

Room Addition Contractor in Los Alamitos - Plans, Permits & Build, One Fixed Price

We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.

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A second-story addition that matches the existing roofline
A second-story addition with a balcony, matched to the original house
A compact kitchen inside a new ADU
A new modern ADU with wood cladding
The bedroom inside a new ADU
The bathroom inside a new ADU
A small deck outside a new ADU
The living room inside a new ADU
Every project starts with

A free site visit, a check of what your lot allows and a written, line-item price.

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Fast, Reliable Room Addition Contractor Across Los Alamitos

Adding a room in Los Alamitos usually comes down to one thing before anything else: what your lot will legally allow. Most homes here sit on tighter lots than people expect, and the city’s lot-coverage and rear-yard setback rules often shape the project more than your budget does. We’re Benson ADU Builders, and our Room Addition Contractor team handles that whole puzzle from first sketch to final inspection. If you’re weighing a room addition anywhere in Los Alamitos, call (903) 568-7222 and we’ll give you a written price before any work starts, not a verbal ballpark that shifts later.

Call (903) 568-7222

Why Benson ADU Builders Is Los Alamitos’s Preferred Room Addition Contractor Company

A single-story rear room addition with tall windows and a new patio

Los Alamitos homeowners tend to ask the same three questions: can this even be built on my lot, what will it really cost, and who exactly is showing up at my door. We answer all three in writing before demo day. Troy Eastman leads our team, and he’s built our process around the idea that a contractor should be as transparent as the rideshare app in your pocket. You get a written price, a real schedule, and background-checked, uniformed technicians on site. No surprises at the door, no scope creep billed after the fact.

We’re part of the Relay Home Co. family, founded in 2006, and every project carries our 365-Day Done Right Promise. If the work isn’t right within a full year, we make it right. That guarantee is stamped on every contract, and it’s why Los Alamitos homeowners keep our number. Dispatch and scheduling are coordinated from our Los Angeles office, and crews serve Los Alamitos locally. A live person answers every call, 24/7, so you’re never waiting until Monday morning for a callback.

Modular Home Addition in Los Alamitos

A Modular Home Addition in Los Alamitos means the room is built as factory-made panels or modules, then assembled on your foundation. For Los Alamitos lots with tight access or a short construction window, modular work cuts on-site framing time significantly. A typical modular room addition in Los Alamitos runs $180 – $340 per square foot depending on finish level, foundation condition, and whether the roofline ties into the existing home or stands separately. The permit path is the same as stick-built work, and the City of Los Alamitos still reviews structural, energy, and lot-coverage plans before we can set anything.

Prefab Panels and Site Fit

On some Los Alamitos lots we recommend a hybrid approach: site-built foundation and utility rough-ins, with prefab wall panels from brands like Abodu or Cover. These panels arrive pre-insulated and pre-sheathed, which speeds things up without sacrificing the roofline match that matters on older Los Alamitos homes.

When Modular Makes Sense

If your rear-yard access is narrow or you’re building close to the setback line, modular delivery and assembly can keep the job cleaner and faster. We walk the lot with you before recommending anything, because not every Los Alamitos lot can accept panel delivery without taking down a fence. The written price you get covers that assessment, not just the build.

Home Addition Plans in Los Alamitos

A new sunroom addition with three walls of windows

Home Addition Plans in Los Alamitos are where most projects are won or lost. Los Alamitos is a small, mostly built-out city where most residential lots are already close to their allowable lot coverage and rear-yard setback limits. That means your room addition usually hinges on how much existing footprint can be legally reused or expanded before a variance is required, not on raw square footage. We pull the building permit through the City of Los Alamitos before framing, a full plan check with structural, energy (Title 24), and lot-coverage review.

Reusing Existing Footprint

A patio enclosure or garage conversion can often proceed under different rules than a new foundation pour, but only if the existing slab or structure actually qualifies. On a corner lot near the Rossmoor border along Green Street, our crew framed a 340 sq ft rear room addition after the homeowner assumed the existing concrete patio could simply be enclosed. The slab had to be re-poured with proper footings, and our James Hardie siding package was matched to the original stucco so the addition read as original construction. The finished room matched the house’s roofline, and the homeowner avoided a setback variance by keeping the addition within the existing rear-yard line.

What the Plan Set Includes

A full plan set in Los Alamitos covers structural drawings, Title 24 energy calculations, lot-coverage and setback verification, and the materials list. If you skip this step and treat the addition like a cosmetic remodel, you’ll discover mid-build that the city won’t pass rough framing without it. We handle the full plan check so you don’t end up with a partially framed room and a stop-work notice.

Trusted Brands We Service in Los Alamitos

We’re authorized to build with Abodu, Cover, Dvele, and James Hardie materials, which means Los Alamitos homeowners get curated options instead of a single take-it-or-leave-it product. You can research any of those names independently before you sign anything. We stock the trim, flashing, and panel components for these systems in common configurations, so Los Alamitos turnarounds don’t stall waiting on a cross-country shipment. If you want a Dvele module or a James Hardie cladding package on your addition, we quote it exactly and order it before the permit is even issued.

Common Room Addition Contractor Problems We See in Los Alamitos Homes

  • Underscoped permit sets. We regularly meet Los Alamitos homeowners who assumed a room addition only needed a simple remodel permit, then discovered the City of Los Alamitos requires a full plan check with structural, Title 24, and lot-coverage review before a single wall can be framed. That discovery usually happens after demolition has started, and it’s expensive to unwind.
  • Enclosing a patio that was never meant to be living space. An existing concrete patio slab or covered patio often sits close to the property line and lacks new footings, vapor barrier, and insulation. On Los Alamitos’s smaller, older lots, this is one of the most common failures we see once the walls start going up.
  • Roofline and stucco mismatches. A fixed price set before the existing roof or exterior finish is opened up often leads to change orders when the new addition has to tie into an old stucco or roofline that no longer matches current materials or codes. We open the wall, check the tie-in points, and update the written price before you’re committed.
  • Setback surprises on narrow lots. Many Los Alamitos homes sit on lots where the rear-yard setback and lot-coverage math leaves very little room. We verify the legal buildable area before designing anything, so you don’t fall in love with a footprint the city will never approve.

Pricing for Room Addition Contractor in Los Alamitos, CA

Room additions in Los Alamitos run about $220 – $420 per square foot depending on whether we’re enclosing an existing covered patio, extending on a new foundation, or building a modular addition. A 300 sq ft rear addition typically lands between $66,000 and $126,000 all-in, including permits, plan check, foundation, framing, electrical, insulation, drywall, paint, and exterior finish. The two cost drivers that move the number the most are foundation condition (re-pouring a patio versus pouring fresh footings) and roofline tie-in complexity. Every project gets a written price before work starts. No verbal estimate that shifts at the door. Call (903) 568-7222 for an exact quote, estimates are free.

We Also Serve Cities Near Los Alamitos

We run room additions across Los Alamitos and into Cypress, Hawaiian Gardens, Seal Beach, and La Palma. If you’re just over the city line, call (903) 568-7222 and we’ll confirm coverage and schedule a lot assessment. The same written-price guarantee applies everywhere.

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 Room Addition Contractor in Los Alamitos

Why Los Alamitos Chooses Benson ADU Builders

We set the standard for room addition contractor in Los Alamitos.

No Change-Order Surprises

The written quote you sign is the price you pay. Anything we find mid-job gets priced and approved by you in writing before we touch it.

Licensed & Insured

Fully certified technicians who meet all local and state licensing requirements.

Upfront Pricing

No hidden fees, no surprises. You approve the price before any work begins.

Guaranteed Work

Every repair and installation is backed by our workmanship warranty and satisfaction guarantee.

How It Works in Los Alamitos

Getting your room addition contractor handled is simple and fast.

1

Call or Request a Free Estimate

Tell us about your room addition contractor needs and we provide an upfront, transparent quote - no obligation, no hidden fees.

2

Licensed Technician Dispatched

A background-checked, certified technician arrives in Los Alamitos - typically within 30-60 minutes, with parts stocked on the truck.

3

Problem Solved, Guaranteed

We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.

What happens when you call

  1. 1
    A real person answersNo phone trees - talk to a local room addition contractor pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
  3. 3
    We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
  4. 4
    You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.

What Los Alamitos Customers Say

Trusted by homeowners across Los Alamitos and surrounding areas.

★★★★★

"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. · Verified customer
★★★★★

"Clean, quiet crew. They respected the neighbors, kept noise to working hours, and swept the driveway every evening."

Hope C. · Verified customer
★★★★★

"Communication was the best part. I always knew what was happening that week without having to ask."

Dolly N. · Verified customer

More ADU services in Los Alamitos

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