A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Room Addition Contractor Across Los Angeles
A room addition in Los Angeles typically runs $250 – $450 per square foot before permit fees, depending on foundation work, roofline changes, and whether the site triggers Hillside or Coastal review. Most standard additions take 5 – 8 months from first plan check to final inspection, with LADBS plan check alone consuming 6 – 12 weeks on a clean submittal. If you’re weighing a 400 sq ft bedroom bump-out against a 900 sq ft primary suite, the numbers matter before the first wall comes down. Our crews work Echo Park, Woodland Hills, San Pedro, and everywhere between, and we put the price in writing before any work starts. Call (361) 315-4177 for a free estimate.
Why Fielding ADU Builders Is Los Angeles’s Preferred Room Addition Contractor Company
Fielding ADU Builders operates as an independently owned member of the Garrison Partners family, which has built to The Garrison Standard since 2006. That standard is simple: a written price before work begins, permits pulled by the book, background-checked uniformed crews on site, and a written one-year guarantee on the finished job. Homeowners who have already been burned by a contractor that missed the schedule or moved the number at the door tend to appreciate the difference.
We answer the phone with a live person around the clock, so when you call about a LADBS correction notice or a subcontractor question at 9 p.m., someone picks up. Our crews know Los Angeles permitting quirks, from Hillside Area conditional use reviews to Coastal Development Permit triggers that most out-of-area builders never see coming. Reed Calloway leads the team and signs off on every room addition scope before we hand you the written price.
We also work the full range of build methods: conventional framing with James Hardie siding, plus prefab and modular platforms like Abodu, Cover, and Dvele. That matters in Los Angeles because lot coverage limits, rear setbacks, and Hillside constraints often make one method dramatically cheaper than another. We match the method to your lot, not the other way around.
Modular Home Addition in Los Angeles
Modular home addition in Los Angeles means building the new space in a factory and assembling it on your lot, which can save 6 – 10 weeks of on-site framing time and cut weather delays that plague stick-built work near the coast and in the canyons. A modular addition in Los Angeles typically runs $220 – $380 per square foot depending on the module count, foundation upgrades, and whether your site can accept a crane or needs a panelized assembly instead. Homes in the flats of the Valley, for example, often take a crane easily, while hillside lots in Mount Washington may require panelized modular that costs more to set.
Factory-Built Modules, Assembled On Your Lot
We work with Abodu, Cover, and Dvele on modular additions where the roofline, setbacks, and floor plan align with what factory construction does well. The modules arrive pre-sheathed and pre-windowed, then our crew sets them on the foundation, ties in the roof, and handles the mechanical connections plus LADBS inspections.
When Modular Beats Stick-Built
If your Los Angeles home sits on a tight lot with limited staging space, modular means fewer material deliveries and less time with a dumpster in the driveway. It also locks in the wall assembly quality, because the modules are built indoors with consistent tolerances, then bolted and sealed on site.
Home Addition Plans in Los Angeles
Home addition plans in Los Angeles are the documented drawings and calculations you submit to LADBS for plan check, and they cost $6,000 – $18,000 depending on whether you need structural engineering, Title 24 energy modeling, or Hillside/Coastal discretionary packages. A clean submittal from a drafter who knows LADBS forms can clear first review in 6 weeks, while a sloppy set of online-bought plans often bounces through 3 or 4 correction cycles and lands you 4 months behind before you ever break ground. We prepare plans in-house and walk them through LADBS ourselves.
Measure, Draw, Submit
The plan set includes floor plans, elevations, a site plan showing setback compliance, structural calcs, Title 24 energy forms, and any Green Building Code documentation LADBS requires. For additions over 500 sq ft in single-family zones, the plans must also show lot coverage math so the city can verify you stay under the 45% cap.
Plan Check Corrections and Resubmittals
Most Los Angeles plan check delays trace back to missing Energy Code or Green Building Code forms, not bad drawings. We submit the full package the first time, and when LADBS issues corrections, we turn them around quickly because we see the same correction types every week from Echo Park to Westchester.
Trusted Brands We Service in Los Angeles
We build with and service the systems Los Angeles homeowners are already researching: Abodu, Cover, Dvele, plus conventional James Hardie siding builds. When you call about a modular addition, we can walk you through the real tradeoffs between Abodu’s panelized system and Cover’s fully finished modules for your specific lot and budget, and we keep the materials moving so a module order doesn’t stall your foundation. For a 600 sq ft Echo Park addition, for example, we used James Hardie siding matched to the original stucco so the new wing read as part of the 1920s structure, not a bolt-on box.
Common Room Addition Contractor Problems We See in Los Angeles Homes
- Unpermitted prior work that kills the new permit. A surprising number of Los Angeles homes have an older garage conversion, patio enclosure, or extra bathroom that was never permitted. LADBS flags it during plan check, and the room addition permit gets held until that prior work is corrected or removed. The fix can add $8,000 – $30,000.
- Foundation surprises on raised floors. Many 1920s – 1950s bungalows in Mid-City and Highland Park sit on raised foundations with girders and posts that were never sized for added load. Once we open the floor, we often find rot, undersized footings, or seismic strapping gaps that must be corrected before framing can pass inspection.
- Hillside and Coastal triggers nobody flagged up front. A 500 sq ft addition in a Hillside Area or within the Coastal Zone can trigger a discretionary review that adds 3 – 6 months. We flag this before pricing, because it changes both the budget and the calendar dramatically.
- Roofline conflicts with neighbor views and solar panels. Los Angeles has view preservation review in some hillside neighborhoods, and many existing roofs already carry solar arrays. A poorly planned roofline can create a view complaint or force a solar rework that costs $4,000 – $12,000.
Pricing for Room Addition Contractor in Los Angeles, CA
A standard stick-built room addition in Los Angeles runs $250 – $450 per square foot. A 400 sq ft bedroom and bath addition usually lands between $100,000 and $180,000. A 900 sq ft primary suite with a full bathroom, walk-in closet, and upgraded finishes typically falls between $225,000 and $405,000. Modular additions run $220 – $380 per square foot, and home addition plans cost $6,000 – $18,000 before construction begins. These ranges include framing, roofing, electrical, plumbing, drywall, paint, and standard finishes, but not permit fees, which LADBS sets separately. Foundation corrections, Hillside/Coastal discretionary work, and solar panel rework are the main line items that change a Los Angeles price once plans come back from plan check. Call (361) 315-4177 and we’ll put a written line-item price in front of you, free.
We Also Serve Cities Near Los Angeles
Our Los Angeles crews also run room additions in Los Angeles metro edge cities like Huntington Park, South Gate, Bell, and Maywood. If you’re in one of those areas and want the same written-price, permitted-work, one-year-guarantee approach, call us and we’ll schedule a free estimate. Distance doesn’t change the standard.
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 Room Addition Contractor in Los Angeles
No, a room addition attached to your existing house is permitted as a single-family dwelling addition, not an ADU, as long as the new space shares access and isn’t set up as a separate living unit. But the line blurs in Los Angeles because a 500 sq ft addition that includes a kitchenette and exterior door can trigger ADU classification, which pulls in different lot coverage and parking rules. If you’re planning a primary suite or family room with no kitchen, you file as a standard addition; add cooking facilities, and LADBS may route you through ADU review. Call (361) 315-4177 and we’ll tell you which path your layout falls under before you spend money on plans.
Plan for 6 – 12 weeks on a clean LADBS submittal, plus another 2 – 6 weeks if corrections are required, and 3 – 6 additional months if Hillside Area or Coastal Development review applies to your lot. Most Los Angeles room additions clear plan check in 8 – 16 weeks total, then construction runs 3 – 6 months after the permit is issued. Our Room Addition Contractor team manages the submittal and correction cycle so you’re not chasing LADBS counters yourself.
Foundation condition is the biggest one, especially on older raised foundations in neighborhoods like West Adams or Eagle Rock where seismic strapping and footings often need upgrades. The second is whether your lot sits in a Hillside Area or Coastal Zone, which layers discretionary review costs onto the job. Roofline complexity, solar panel rework, and finish level follow close behind. A 400 sq ft addition on a flat Valley lot with a clean foundation can stay near $110,000, while the same footprint on a hillside with a failing girder system can push past $180,000. The free estimate we give you at (361) 315-4177 includes the foundation condition check, so the number you approve is the number you pay.
Yes, modular room additions are permitted in Los Angeles and can work well on lots with crane access and standard setbacks, like much of the San Fernando Valley and the flats of the Westside. Hillside lots with narrow access or steep grades often need panelized modular instead, which costs more to set. We work with Abodu, Cover, and Dvele, and we’ll tell you honestly if your lot is a good modular candidate or if stick-built is the cheaper route.
LADBS will inspect foundation and excavation, framing, rough electrical, rough plumbing, insulation, drywall, and a final building inspection, plus any Hillside or Coastal conditions attached to your permit. You’ll also need a separate LA Department of Water and Power or SoCalGas inspection if utility work is involved. We pull the permits, schedule the inspections, and stand on site for each one. If anything fails, we correct it and get the re-inspection scheduled immediately.
Not unless the written scope changes. The Garrison Standard is a written price handed to you before any work starts, and the number you approve on day one is the number on the final invoice. If LADBS corrections reveal foundation work or unpermitted prior construction that wasn’t visible during estimating, we price that change in writing and you approve it before we proceed. No surprises at the door. Call (361) 315-4177 for your free estimate.
Written by Reed Calloway, Owner at Fielding ADU Builders, serving Los Angeles since 2006.
