







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 Westwood
Room additions in Westwood run $180 – $420 per square foot before permit fees, with most projects landing between $90,000 and $280,000 depending on site access and hillside conditions. If you’re on a downslope lot near the Santa Monica Mountains, expect the higher end: those jobs require shoring, drainage work, and marine-grade materials that flat-lot builders never think about. Our crews work Westwood weekly, know the local building department’s expectations for hillside construction, and put the price in writing before anything gets torn apart. Call (213) 732-1415 to schedule a free estimate.
Why Fielding ADU Los Angeles Is Westwood’s Preferred Room Addition Contractor Company

We’re the Room Addition Contractor team inside Fielding ADU Los Angeles, part of the Garrison Partners family that has been building to The Garrison Standard since 2006. That standard is simple: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year. Westwood homeowners tend to be exacting about that last part, and for good reason. The housing stock here is largely 1920s through 1950s single-family homes, plenty of Spanish Colonial Revival and ranch styles, often on smaller lots with mature trees that complicate foundation work and material delivery.
Reed Calloway, who leads our Westwood work, has walked more hillside lots off Veteran Avenue and Gayley Avenue than he can count. He knows which downslope streets trigger extra shoring review and which flat blocks near Westwood Village can take a standard foundation without drama. Every crew member who arrives at your door has been background-checked and wears a uniform, so you always know who is on your property. And if you call at 2 a.m. with a question about your project, a live person picks up, not a voicemail queue.
Serving Westwood means knowing the difference between a flat-lot addition off Midvale Avenue and a hillside addition south of Sunset Boulevard. The first is straightforward; the second requires drainage planning, retaining wall coordination, and material choices that hold up to coastal air. That local knowledge is why homeowners who already got burned by a fly-by-night contractor end up calling us to fix the mess.
Sunroom Builders in Westwood
Sunroom builders in Westwood contend with conditions that inland crews never see: salt air drifting in from the coast, steep downslope lots, and a building stock that predates modern drainage codes. A Westwood sunroom is not a four-season room bolted onto the back of a house; it’s a structural addition that has to shed water correctly on a slope, handle the marine layer’s corrosion cycle, and match a design review board’s expectations near UCLA. Sunroom projects in Westwood typically run $110,000 to $240,000 depending on glazing, foundation depth, and whether the lot slopes toward or away from the house.
Glazing and Frame Selection
We specify marine-grade aluminum frames for Westwood sunrooms, not the vinyl or standard aluminum you’d put on a Calabasas addition. Standard zinc-plated hardware pits within five to seven years here. Marine-grade finishes cost 12 – 18% more upfront and buy you decades before seal failure.
Hillside Foundation Work
On a downslope lot, the sunroom’s foundation often has to be stepped or pinned deeper than code minimums. We coordinate shoring and drainage before the first pour, because water moving through loose, sloping soil will find the joint where new concrete meets old hillside foundation.
Room Additions in Westwood

Room additions in Westwood mean adding square footage to homes built between the 1920s and 1950s, many of them Spanish Colonial Revival or ranch styles on compact lots with protected trees and specific setback limits. A bedroom or family room addition here typically runs $95,000 to $260,000, and the spread comes from site access on narrow hillside streets plus the need for upgraded fasteners and finishes that stand up to coastal air. You’ll also need to know whether your lot falls under Westwood’s hillside construction regulations, which can add geotechnical review time.
Matching the Existing Structure
Westwood’s Spanish Colonial Revival homes have thick stucco walls and clay tile roofs; ranches have low eaves and horizontal siding. We match profiles, not just colors, so the addition reads as part of the original house rather than a box nailed on the side. That matters here, where neighborhoods near UCLA hold their character closely.
Drainage at the Connection Point
The most common failure we see on Westwood room additions is water intrusion where the new foundation meets the old hillside structure. We install sub-surface drains and waterproofing membranes at that joint as standard, not as an upgrade.
Trusted Brands We Service in Westwood
We work with the systems Westwood homeowners are already researching: Abodu and Cover for prefab ADU Builders - Westwood projects and room extensions, Dvele for high-performance modular builds, and James Hardie siding for conventional construction that holds its finish against coastal moisture. Stocking the right marine-grade fasteners and flashing for these systems means we do not get caught waiting on coastal-spec parts when your project is mid-frame. If you have been quoted a prefab unit and a conventional build, we can walk you through which one fits your lot and your budget before you commit.
Common Room Addition Contractor Problems We See in Westwood Homes
- Salt air corrosion on standard galvanized fasteners. Inland contractors often specify zinc-plated hardware because it passes code everywhere. On Westwood’s hillside homes, that hardware rusts and loosens within five years, especially on railing posts and window frame anchors exposed to the marine layer.
- Improper drainage on downslope lots. A room addition that works on a flat lot can become a water trap on a sloped one. Without sub-surface drains at the foundation connection, water follows the path of least resistance and shows up inside the new room within two rainy seasons.
- Inland-grade window frames with pitting and seal failure. Standard aluminum frames without marine finishes pit within a decade near Westwood’s coastal influence. Once the seals fail, you get drafts, condensation, and eventually framing rot.
- Paver patios with sand that washes out. The loose, sloping soils near the Santa Monica Mountains shift under standard paver installations. We use polymeric sand with a stabilizer and compacted base, plus sealed joints, so the patio stays level through wet winters and warm summers.
Pricing for Room Addition Contractor in Westwood, CA
Here are straight numbers for Westwood’s market. A sunroom runs $110,000 to $240,000. A conventional room addition runs $95,000 to $260,000. The reason the range is wide comes down to three things: whether your lot is flat or downslope, how much marine-grade material your exposure requires, and whether the design review process adds time. A flat-lot addition near Westwood Village with standard components sits at the lower end. A hillside addition south of Sunset with coastal-spec windows, stainless fasteners, and shoring work sits at the upper end. Every estimate from us is line-item, written, and free. The price you approve on day one is the price on the final invoice, guaranteed by The Garrison Standard. Call (213) 732-1415 for a free estimate.
We Also Serve Cities Near Westwood
We work throughout the Westside, including Room Addition Contractor in Westwood, West Hollywood, Beverly Hills, Culver City, and the broader Los Angeles area. If your project sits near the city line, we’ll still come out, walk the lot, and give you a written price.
Serving Westwood, CA - Our Local Coverage Area
We’re based in the Westwood 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 Westwood
Three factors drive the difference: hillside foundation work on downslope lots, marine-grade material upgrades for salt air, and design review requirements near UCLA. A flat-lot addition in Van Nuys might not need any of the three. A hillside addition in Westwood needs all of them, and each adds 8 – 15% to the total. Call (213) 732-1415 for a free written estimate that shows exactly where your money goes.
We specify stainless steel or hot-dip galvanized fasteners on every Westwood project, never standard zinc-plated hardware. Salt air from the coast corrodes zinc plating within five to seven years, causing loosened clips and premature roof failure. Stainless costs more upfront but lasts the life of the structure.
We install sub-surface drains and a waterproofing membrane at the foundation connection where new construction meets existing hillside structure. This is standard on our Westwood jobs, not an upgrade. Without it, water follows the slope and intrudes at the joint within two rainy seasons.
Marine-grade aluminum frames are what we specify for Westwood sunrooms. Vinyl and standard aluminum frames pit and lose their seals within a decade here. Marine-grade finishes run 12 – 18% more upfront and eliminate the coastal retrofit you would otherwise need by year ten. Call (213) 732-1415 to get a window budget in writing.
Yes. We seal paver joints with polymeric sand and a stabilizer, then compact the base before laying pavers. Westwood’s loose, sloping soils shift over time, and standard sand washes out during wet winters. Sealed joints keep the patio level and reduce maintenance.
If you have more questions about your specific lot, call (213) 732-1415. A live person answers, day or night, and we’ll walk you through the process for your street and your budget.
Written by Reed Calloway, Owner at Fielding ADU Los Angeles, serving Westwood since 2006.









