A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Los Angeles
Adding square footage to a house in Los Angeles means navigating LADBS plan check, fire-separation rules, and older housing stock that rarely matches its original blueprints. Benson ADU Builders handles that from the first site visit: we scope the addition, flag the permit triggers, and put a written price in front of you before any work starts. Our Los Angeles office coordinates crews across the metro, so the team that quotes your project is the one that builds it. Call (903) 568-7222 to schedule a free estimate, and we’ll walk the property with you and tell you exactly what the addition will take. No verbal ballparks. No price that shifts at the door.
Key Takeaways:
- A typical home addition in Los Angeles runs $250 – $450 per square foot depending on scope, finish level, and whether the addition triggers fire-rated assemblies near property lines.
- LADBS plan check and inspection scheduling usually gates the timeline more than construction labor does.
- Every project gets a written price, a 365-Day Done Right Promise, and real-time tracking through The Relay Visibility Guarantee.
- We build with James Hardie cladding and can source prefab systems from Abodu, Cover, and Dvele for faster, cleaner builds.
Why Benson ADU Builders Is Los Angeles’s Preferred Home Addition Contractor Company
Los Angeles homeowners deal with a specific set of realities: 1920s bungalows in Highland Park sit on lots where the side setback is measured in inches, while 1950s stucco boxes in Westchester hide galvanized plumbing behind drywall that hasn’t been opened in seventy years. Our crews have worked through enough of these to know what to look for before the first wall comes down. That local familiarity means the quote you get reflects what we’ll actually find, not what a generic bid assumed.
Every job runs under The Relay Visibility Guarantee. You get a written price before work starts, a written guarantee on the completed project, and a 365-Day Done Right Promise that says if something isn’t right within a full year, we make it right. The technicians who show up at your Los Angeles home are background-checked and in uniform, and someone answers the phone around the clock. Troy Eastman leads the team, and he holds every project to the same standard: if it’s not in writing, it didn’t happen.
We’re part of the Relay Home Co. family, founded 2006. Our Home Addition Contractor team brings that structure to every project we take on in Los Angeles.
Sunroom Addition in Los Angeles
A sunroom addition in Los Angeles typically runs $180 – $320 per square foot, and it’s one of the more cost-effective ways to add living space without touching the main roofline. We build them as conditioned spaces with proper insulation, glazing, and a foundation that meets LADBS standards, so the room works year-round instead of becoming a hotbox in August. The biggest variable is glazing: single-pane costs less up front, but double-pane low-E glass holds temperature better and cuts the cooling load during Santa Ana stretches.
Foundation And Access
Most Los Angeles sunrooms go on a slab-on-grade or a raised perimeter footing, depending on what the existing house sits on. If the addition lands within 5 feet of a side or rear property line, LAMC Chapter 9 requires a 1-hour fire-rated wall assembly, which adds framing and drywall scope. We include that in the written price from the start, because it’s not optional and it’s not a surprise.
Glazing And Orientation
In Los Angeles, west-facing glass turns a sunroom into an oven by mid-afternoon between June and October. We spec glazing and overhangs for the actual orientation of your lot, which is something a one-size-fits-all sunroom kit never accounts for. The result is a room you’ll actually use, not one you’ll avoid from 2 p.m. onward.
Second Story Addition Contractor in Los Angeles
A second story addition contractor in Los Angeles has to deal with two things most cities don’t: a plan-check queue that can stretch for months and existing foundations that were never engineered to hold another floor. A second-story addition here typically runs $300 – $500 per square foot, and the range swings on whether we’re adding over an existing footprint or cantilevering, plus what the soil report and existing foundation say. We handle the full scope: structural engineering, LADBS submittal, shear walls, hold-downs, and matching the new exterior to the old.
Working With Existing Structure
We built a 480-square-foot second-story addition plus a ground-floor sunroom for a family on West 74th Street in the Westchester area near LAX, tying the new framing into a 1950s stucco house with a raised foundation. After LADBS plan check, we poured a new footing, ran shear walls and hold-downs to the existing structure, and matched the original stucco with James Hardie siding on the addition’s upper portion. The rough framing and final inspections cleared, and the family gained a primary suite plus a sunroom without touching the front setback.
Hidden Conditions To Budget For
Older Los Angeles housing stock hides things: knob-and-tube wiring, galvanized supply lines, or a prior non-permitted addition that’s now part of the structural load path. We open walls before we finalize the number, not after you’ve signed. If the framing reveals a problem, we document it, explain the fix, and update the written price before proceeding.
Trusted Brands We Service in Los Angeles
We build with James Hardie cladding on a large share of our Los Angeles additions because it handles the dry heat, the marine layer, and the occasional heavy rain without warping or peeling. For homeowners who want a faster, cleaner build, we can source prefab systems from Abodu, Cover, and Dvele, which take a significant portion of the framing offsite and shorten the time your yard is a construction zone. Our Los Angeles customers appreciate being able to research those brands independently, and we stock the common trim, flashing, and panel profiles locally so we’re not waiting on a truck from out of state when a run is short.
Common Home Addition Contractor Problems We See in Los Angeles Homes
- Plan-check and inspection delays get blamed on the contractor. A crew can be ready to start, but the LADBS queue controls when the permit issues and when inspections land. We build the calendar around the city’s schedule and tell you the real timeline up front, not a start date that assumes everything clears in two weeks.
- Property-line fire-separation rules get missed in cheap bids. LAMC Chapter 9 requires 1-hour fire-rated wall assemblies when an addition sits within 5 feet of a side or rear property line. A generic bid omits that, then hits you with a change order mid-framing. We include it from the first quote.
- Additions on sloped lots trigger the Baseline Hillside Ordinance. If your Los Angeles lot has any meaningful grade change, the engineering scope changes: taller stem walls, deeper footings, and possibly a soils report. We look at the slope on the first visit and price accordingly.
- Hidden wiring and plumbing in pre-1980 houses. Knob-and-tube wiring behind the walls or galvanized supply lines that have rusted through show up after demo. We open walls before the final price locks in, so the number you sign reflects the house as it actually exists.
Pricing for Home Addition Contractor in Los Angeles, CA
Here’s what we see across Los Angeles right now. A sunroom addition runs $180 – $320 per square foot. A second-story addition runs $300 – $500 per square foot, with the higher end covering structural upgrades to the existing foundation and shear-wall work. A garage addition or bump-out typically lands at $200 – $350 per square foot. What moves the number: property-line proximity and the fire-rated assemblies it requires, the condition of the existing foundation, whether the lot sits on a slope, and the finish level you choose. We give you a written line-item price before work starts, and that number only changes if you change the scope. Call (903) 568-7222 to schedule your free estimate.
We Also Serve Cities Near Los Angeles
Beyond Los Angeles proper, our crews regularly work in Huntington Park, South Gate, Bell, and Maywood. The permitting rules in those cities share a lot with Los Angeles, but each has its own quirks around setbacks and plan check. We handle the specific submittal requirements for whichever jurisdiction your property falls in, so you don’t have to translate the municipal code yourself.
Serving Los Angeles, CA - Our Local Coverage Area
We’re based in the Los Angeles 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 Home Addition Contractor in Los Angeles
No, you don’t need a separate ADU permit unless the addition creates a second dwelling unit with its own kitchen. A second-story addition or sunroom that stays part of the primary house goes through a standard LADBS building permit for additions and alterations. What does matter: if the addition is within 5 feet of a property line, it triggers the 1-hour fire-rated assembly requirement, and if the lot is on a slope, the Baseline Hillside Ordinance may add engineering scope. We handle both in the initial scope. Call (903) 568-7222 and we’ll tell you exactly which permit path applies to your property.
A realistic timeline for a home addition in Los Angeles is 2 to 5 months from submittal to issued permit, depending on LADBS plan-check queue volume and whether the project requires structural review or hillside review. That’s before construction starts. The actual build for a sunroom is typically 4 to 8 weeks once the permit is in hand, and a second-story addition usually runs 3 to 5 months. We build the full calendar around the city’s schedule so you know the real timeline before you commit. Call (903) 568-7222 for a project-specific estimate.
The biggest cost drivers are property-line proximity, existing foundation condition, lot slope, and finish level. A fire-rated wall assembly near a property line adds framing and drywall scope. A raised foundation from the 1950s may need new footings and shear-wall tie-ins. A sloped lot under the Baseline Hillside Ordinance adds stem-wall height and possibly a soils report. Finish choices like flooring, countertops, and glazing swing the number by $50 – $100 per square foot. We itemize all of it in the written price. Call (903) 568-7222 to schedule a free estimate.
Yes, we match the existing exterior as closely as the structure allows. On the West 74th Street project, we tied a 1950s stucco house into a new second story using James Hardie siding on the addition’s upper portion, and the result read as one continuous house, not a box dropped on top. For sunrooms, we match the roofline where practical and carry the same trim profiles through the new space. If a perfect material match isn’t possible because the original product is discontinued, we show you samples and put the choice in writing. Call (903) 568-7222 to talk through your project.
The price changes only if we find hidden conditions we couldn’t see before opening walls, and you approve the updated scope in writing. Knob-and-tube wiring that has to come out, galvanized plumbing that’s failed, or a prior non-permitted addition that has to be brought up to code are the common ones in older Los Angeles homes. We open the walls before finalizing the number whenever possible, so most of those discoveries happen before you sign. If something surfaces mid-build, we document it with photos and a written change order, and nothing proceeds until you approve it. That’s the Relay Visibility Guarantee, and it’s how every project runs. Call (903) 568-7222 to schedule your free estimate.
Written by Troy Eastman, Owner at Benson ADU Builders, serving Los Angeles, CA.
