
Room Addition
Contractor in Tarzana, CA
More room without moving — room additions, primary suites, and second stories, engineered and permitted through LADBS and matched to your Tarzana home, on the flats or up in the hills. CSLB #1021284.
Right Image Builders is a licensed room addition contractor serving Tarzana, CA. We build rear room additions, primary-suite wings and second stories for Tarzana's larger residential lots — level parcels on the flats north of Ventura and Hillside Area parcels in the Tarzana hills to the south — engineered and permitted through LADBS, with hillside and fire-zone review where a specific parcel calls for it. As your home addition contractor we carry plans, structural engineering, permits and construction under one fixed-price contract. CSLB #1021284, licensed since 2016, insured, a straight drive east on the Valley floor to our Valley Glen shop. Free on-site consultation: (818) 210-4544.
More Room,
Without Moving
Outgrowing your Tarzana home doesn't have to mean buying a bigger one — with today's prices, staying and adding on is often the smarter move. A well-built addition gives you the extra bedroom, the primary suite, the bigger kitchen, or the second story you need, and it does it on the street and in the school district you already chose.
Right Image Builders is a licensed general contractor based in Valley Glen, a straight drive east on the Valley floor. An addition is a serious structural project — new foundation, framing tied into the existing house, roof and systems extended, all engineered and permitted. We manage the whole thing: architectural plans, structural engineering, LADBS permits, and construction, under one written fixed-price contract and one accountable company.
Tarzana's lots shape what's possible. On the big, level flats north of Ventura Boulevard, there's genuine room for a large ground-floor addition or a primary suite. South of Ventura, in the upscale, semi-rural Tarzana hills, additions run into the City of LA Hillside Ordinance — grading, access, and drainage that have to be engineered from the start. The art either way is making the new square footage look original — matched rooflines, stucco, and windows — not bolted on.

Ways to Add
Space in Tarzana
Rear & Ground-Floor Room Additions
A new bedroom, family room or office built off the back of the house on its own foundation and roof, framed into the existing structure and permitted through LADBS — on Tarzana's level lots north of Ventura there is usually room to build out generously.
Primary Suite Additions
Add the primary bedroom, walk-in closet, and en-suite bath an older Tarzana home may never have had — a high-return addition that transforms how the house lives. On a generous flats lot, there's often space for a genuinely large suite.
Second-Story Additions
When you want to keep the yard — or the lot is a hillside parcel to the south — we build up. Second-story additions require careful structural engineering to carry the new load on the existing foundation, exactly the work a licensed contractor engineers and permits. Our second-story addition guide covers the structural evaluation and roof work involved before you decide to build up.
Bump-Outs & Kitchen Expansions
Sometimes a few hundred square feet changes everything — pushing out a cramped kitchen or dining area, or adding a mudroom or breakfast nook. Smaller additions that deliver outsized daily impact.
Engineering, Permits & Hillside
Every addition is designed, structurally engineered, and permitted through LADBS. On hillside homes south of Ventura we also engineer and permit to the Hillside Ordinance — grading, retaining, drainage, and access — and carry the project to signed-off final inspection.
Seamless Integration
Matched rooflines, stucco texture, window styles, and floor heights so the addition reads as part of the original home. The difference between an addition that adds value and one that looks tacked on — and on upscale Tarzana homes, that value is real money.
What Your Tarzana
Lot Will Allow
Every Tarzana addition starts with the parcel — and here, that means which side of Ventura Boulevard you're on. On the flats north of Ventura, including the Vanalden area, the lots are big and level: the rules are mostly floor-area ratio and the front, side, and rear setbacks you have to keep clear, and there's real room for a large ground-floor addition or primary suite.
South of Ventura, in the Tarzana hills, the lots are larger and more valuable, with an upscale, semi-rural feel — but they're governed by the City of LA Hillside Ordinance. Grading limits, retaining, drainage, haul routes, and access all have to be engineered and permitted correctly. Because Tarzana is City of Los Angeles, every addition is permitted through LADBS, and hillside plan check and structural review are more involved than a flats project.
The first thing we do at the free consultation is pull your zoning and tell you honestly what's buildable — square footage, height, and setbacks — before you spend a dollar on design.
Tarzana (ZIP 91356) reads differently on each side of Ventura Boulevard. North of it, the flats — including the streets around Vanalden — are large, level lots where floor-area ratio and setbacks are the main limits and a wide rear addition or a primary-suite wing is straightforward. South of Ventura, the Tarzana hills carry larger, semi-rural parcels; many are designated Hillside Area under the Baseline Hillside Ordinance, which limits grading, height and floor area and adds retaining, drainage and haul-route items to plan check, and some are in a Very High Fire Hazard Severity Zone. We keep Tarzana projects focused: confirm the parcel's designations, pull the zoning, and design the smallest set of structural moves that delivers the space you want.
Tarzana Home Addition
Cost Ranges
| Addition Type | Typical Range | What's Involved |
|---|---|---|
| Bump-Out | $75K–$145K | A few hundred square feet — kitchen or dining expansion, mudroom — with new foundation, framing, and matched exterior. |
| Room / Suite Addition | $145K–$290K | A full room or primary suite — foundation, framing, roof, systems, finishes, engineered and permitted — the large ground-floor additions Tarzana's flats lots allow. |
| Second Story | $290K–$520K+ | Adding a full upper level — significant structural engineering to carry the load, plus stairs, systems, and full finishes. |
Additions vary widely with size, finishes, and structural conditions — hillside homes south of Ventura carry added grading and engineering cost. Ranges are for planning only; your fixed-price proposal follows the free consultation and zoning review. Tarzana projects move within these ranges on square footage, foundation and structural work, second-story reinforcement, hillside or grading conditions, how far plumbing, electrical and HVAC have to move, and finish level; the Los Angeles cost guide explains each driver.
How Long a Tarzana
Room Addition Takes
A Tarzana room addition typically needs a few months of design, engineering and LADBS plan check, then about three to five months of construction for a ground-floor or rear addition and longer for a second story. Hillside parcels south of Ventura should allow extra time for grading and structural review.
On the flats the path is plans and structural calculations, LADBS plan check, then foundation, framing, roof tie-in, rough trades with inspections, drywall, exterior match and finishes. In the hills a grading plan, often a soils report, and Baseline Hillside Ordinance review come before plan check clears, and site access shapes the construction calendar. The fixed-price proposal shows the combined schedule with realistic dates.
Three Steps.
Zero Surprises.
Free Consultation & Zoning Review
We visit your Tarzana home, pull the parcel's zoning, and tell you honestly what you can build — square footage, height, setbacks, and any Hillside Ordinance factors — and which addition fits your goals and budget.
Design, Engineering & Permits
We produce architectural and structural plans, submit through LADBS, and manage plan check — engineering for the hillside where it applies — with a written fixed-price proposal set before construction begins.
Build & Deliver
One crew builds the addition to signed-off final inspection, matched to your existing home. Final payment is due only after your walkthrough approval.
Choosing a Room Addition
Contractor in Tarzana
Verify the license at cslb.ca.gov (ours is 1021284) — active, classified for structural work, bond and workers' compensation on file — and get insurance certificates in writing. Ask who prepares the plans, who engineers the structure and who pulls and closes the LADBS permit; on a Tarzana hillside parcel, ask specifically who is responsible for the grading plan and any soils report, because those items decide whether plan check clears on the first pass.
Require a written fixed-price contract with an itemized scope, named allowances, written change orders and progress payments tied to completed work; California caps the down payment at $1,000 or 10 percent, whichever is less. Ask how the addition's foundation, roof and stucco will be tied into the existing house so it reads as original.
Add On to Your
Tarzana Home
Tell us what you want to add and we'll get back to you within 4 business hours. We'll confirm what your lot allows before you spend anything on design.
Prefer to talk it through?
(818) 210-4544Questions We
Hear in Tarzana
Pool Builder in Tarzana
New gunite pools, spas & decking →
RelatedADU Construction in Tarzana
Want a separate rentable unit instead? →
Same CityKitchen Contractor in Tarzana
Licensed kitchen contractor →
Same CityKitchen Remodeling in Tarzana
Chef's kitchens & great-room layouts →
Same CityBathroom Remodel Contractor in Tarzana
Licensed bathroom contractor →
Service HubRoom Additions — All of LA
Our full room & home addition service →
NearbyHome Additions in Encino
Just east on Ventura →
NearbyRoom Additions in Woodland Hills
Just west on Ventura →
Planning GuideRoom Addition Cost Guide (2026)
How the planning ranges are built →
Planning GuideSecond-Story Additions: What to Know
Structure, stairs, roof, cost →
Planning GuideRoom Addition Permits in Los Angeles
Plans, plan check, inspections →
See Our WorkPortfolio
Recent additions & projects across the Valley →
Build On to Your
Tarzana Home
Free consultation and zoning review. Written fixed-price proposal. One licensed team from design and LADBS permits through to a finished addition matched to your home.
(818) 210-4544
