







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 Van Nuys
A room addition in Van Nuys typically runs $180 – $340 per square foot depending on the structural work your existing house needs, with most 400 – 600 square foot additions landing between $90,000 and $210,000 including finishes. The biggest variable on this city’s post-war stucco-and-slab housing stock is the tie-in: what we discover once we open the ceiling and see what your 2×4 framing is actually carrying. We scope it honestly before you sign, and the price goes in writing. That’s the whole point. Call (361) 315-4177 to schedule a free estimate.
We work throughout Van Nuys, from the blocks around Van Nuys Boulevard up to the airport influence area and over toward Sepulveda Basin. Our crews know these streets, the permit counter downtown, and the specific structural surprises that show up in houses built between 1940 and 1965. Reed Calloway leads every project, and the crew that walks your site is background-checked and uniformed. You know who’s on your property, and you get a written price before any work starts.
Why Fielding ADU Builders Is Van Nuys’s Preferred Room Addition Contractor Company

We’re an independently owned member of the Garrison Partners family, building to The Garrison Standard since 2006. That standard is five lines, and it’s how we run every Van Nuys project: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year. No contractor-speak. Just the terms on paper.
Our Van Nuys customers tend to be homeowners who’ve already been through one bad build. They mention the same things: a contractor who missed the schedule, moved the price at the door, or left the permit board blank. We exist because those failures are avoidable. The Garrison Standard includes a 365-Day Done Right Promise. If workmanship on your addition fails within that year, we return and correct it at no charge. That guarantee is written, not verbal.
We answer the phone with a live person, 24 hours a day. You call at noon or midnight, a person picks up. For planned construction, we don’t promise same-day anything. We promise a realistic calendar, a written line-item price, and a permit pulled before we open a wall.
ADU Conversion in Van Nuys
ADU conversion in Van Nuys means taking an existing attached garage, a detached garage, or underused space inside your house and turning it into a legal, permitted dwelling unit: its own kitchen, its own bath, its own address for the utility company. On Van Nuys lots, a garage conversion is often the fastest path to rentable square footage because the shell, slab, and roof already exist. What determines the cost is what’s inside those walls: electrical service, plumbing runs, seismic anchoring, and whether the city considers the space habitable without a major structural retrofit. Most attached garage conversions in Van Nuys run $120,000 – $190,000 before permit fees, assuming the slab is sound and the existing framing passes a structural review. Detached garage-to-ADU conversions run higher, typically $180,000 – $260,000, because you’re adding utility trenching and often a new panel.
The honest truth for Van Nuys: a garage built in 1955 wasn’t framed to be lived in. The ceiling joists may be undersized, the slab may lack a moisture barrier, and the setback rules around the Van Nuys Airport influence area can restrict how tall or how close to the rear line you can build. We walk the space, check the structural reality, and write a price that reflects what’s actually there, not what a salesperson hopes is there.
Garage-adjacent layout planning
On a typical Van Nuys 50-foot-wide lot, your attached garage already sits at the rear setback line. Converting it into livable space changes the open-space math for the whole property. We work the rear-yard requirement before we quote, because redesigning after you’ve signed is the kind of experience that drives people away from contractors entirely.
Prefab and panelized ADU options
For detached ADUs, we’re fluent with leading prefab platforms including Cover, Dvele, Mighty Buildings, and Boxabl. These systems can shorten the build calendar meaningfully on a Van Nuys lot where access is tight or you want less construction traffic. We’ll match the right build method to your budget and lot constraints, and the written-price rule applies whether we’re assembling panels or pouring foundations.
Sunroom Builders in Van Nuys

Sunroom builders in Van Nuys deal with a specific California condition: a room that needs to hold up to summer heat, valley wind, and the occasional winter downpour while still feeling like part of the house rather than a patio with windows. A sunroom addition in Van Nuys typically runs $65,000 – $120,000 for a 200 – 350 square foot build, depending on whether you want conditioned space tied into your HVAC or a three-season room that carries its own heating and cooling.
The structural conversation in Van Nuys is different from most cities. Your existing post-war house was framed with shallow 2×4 ceiling rafters and sits on a slab. Adding a sunroom that ties into that roofline means the existing ceiling assembly often needs reinforcement at the connection point, not just new headers at the opening. We plan for that in the written price from day one, so the number you approve doesn’t move when the engineer weighs in.
Foundation and glazing decisions
Sunrooms on Van Nuys slabs can often use the existing concrete if we’re staying within the original footprint or building off the rear wall. If the slab has settled or tests show insufficient thickness, we’ll pour a new perimeter footing and tie it properly. Glazing choice matters in this climate too: low-E glass and operable vents keep the room usable from June through September without running your electric bill into the ground.
Attached sunroom permitting
An attached sunroom is treated as a room addition by LADBS, not a patio cover. That means plan check, a structural calc, and a final inspection. We pull the permit ourselves, post the job card, and pass the inspection before you write the final check. There’s no scenario where we ask you to “just live with it” unpermitted.
Trusted Brands We Service in Van Nuys
We work with the systems homeowners in Van Nuys are already researching. For prefab ADUs, that’s Cover, Dvele, Mighty Buildings, and Boxabl. For conventional builds, we use James Hardie siding and Tuff Shed-style structures where the design calls for them. We also stock common replacement hardware and rough-in materials for local builds, which keeps material runs short and the calendar honest. Having a crew that has actually assembled a Dvele or Mighty Buildings module matters: these systems have their own connection details, and a crew that’s never touched one will learn on your dime. We’ve already learned.
Common Room Addition Contractor Problems We See in Van Nuys Homes
- Slab and framing surprises. Houses built in the 1940s and 1950s across Van Nuys were framed with 2×4 ceiling members on slab foundations. When a structural engineer reviews the tie-in, the existing roof-ceiling assembly often needs sistering or a new shear wall, and that’s a legitimate cost that should be in the original quote.
- Airport influence-area plan check delays. Large portions of Van Nuys fall under the Van Nuys Airport influence area, which adds a notification and review layer at LADBS. Skipping that pre-consultation means correction cycles before your permit is even issued.
- Garage-adjacent setback miscalculations. Converting or adding next to an existing garage changes the rear-yard open-space math. Bidding the work without confirming the setback variance first leads to a redesign after you’ve signed.
- Unconditioned sunrooms that roast in August. A sunroom built without low-E glazing or proper venting in Van Nuys heat becomes unusable for four months of the year. That’s a design failure, not a climate problem, and it’s avoidable with the right glazing spec.
Pricing for Room Addition Contractor in Van Nuys, CA
We write real numbers, not ranges pulled from a national website. For Van Nuys specifically: a straight single-story room addition of 300 – 400 square feet runs $75,000 – $140,000 depending on foundation work, roof tie-in, and finish level. A 400 – 600 square foot addition runs $140,000 – $210,000. If the added square footage includes a bathroom or kitchen, plan for the higher end: wet walls, drain lines, and ventilation add $30,000 – $60,000 depending on how far the existing lines need to run. A garage conversion to living space runs $120,000 – $190,000 attached, and a detached ADU conversion runs $180,000 – $260,000. Permit fees, plan check, and school district fees are separate line items and we show them to you before you sign. The price you approve on day one is the number on the final invoice. Call (361) 315-4177 for a free written estimate.
We Also Serve Cities Near Van Nuys
Our crews work throughout the central San Fernando Valley. We serve Sherman Oaks, Studio City, North Hollywood, and Encino with the same written-price policy and the same 365-day guarantee. If you’re a few blocks from the Van Nuys border in any direction, you’re still in our service area. Learn more about our Room Addition Contractor team or see what we do across Van Nuys.
Serving Van Nuys, CA - Our Local Coverage Area
We’re based in the Van Nuys 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 Van Nuys
Adding conditioned living space to a Van Nuys house requires a full LADBS plan check. This isn’t a re-roof or a window replacement. You’re changing the structural load path, the building envelope, and often the electrical service, so the city wants drawings, a structural calculation, and a title-24 energy report. We handle the plan check and corrections as part of the project. Call (361) 315-4177 and we’ll walk you through the exact path for your lot.
Yes. Your existing 2×4 ceiling framing was not designed to carry the added roof loads from a new addition, so the structural engineer will likely call for sistering the existing joists or adding a shear wall at the tie-in. That’s a real cost, typically $5,000 – $15,000 depending on how much reinforcement the engineer requires. We include it in the written price before you sign, not as a change order after demolition.
In most Van Nuys cases, yes. The attached garage already has a roof, a slab, and exterior walls, so the conversion cost runs lower per square foot than new construction. The catch is whether the existing framing and slab meet habitable-space standards. If they don’t, the retrofit costs can eat the savings. We’ll inspect, tell you which path is cheaper for your specific house, and write the price. Estimates are free.
Plan for 5 – 8 months total. The LADBS plan check and any Van Nuys Airport influence-area review typically runs 4 – 10 weeks before a permit is issued. Construction for a 400-square-foot addition runs 3 – 4 months once we open the walls. That calendar includes inspections and our own final walk-through. We give you the schedule in writing at contract signing, and we update it weekly. Call (361) 315-4177 to get a specific timeline for your project.
If we open a wall and find rotted framing or a slab that’s thinner than the drawings assumed, we stop work, show you what we found, and write a change order for only that specific work. You approve it before we proceed. What we don’t do is keep building and hand you a bigger invoice at the end. The Garrison Code is clear on this: price in writing, by the book, no surprises at the door. For the full breakdown on your house, call (361) 315-4177.
Written by Reed Calloway, Owner at Fielding ADU Builders, serving Van Nuys under The Garrison Standard.








