Room Addition Contractor in Los Angeles
Bedroom, primary suite, second-story and bump-out additions — designed, permitted and built by one licensed team. CSLB #1155602, insured and BBB Accredited. Free, itemized estimates.
A room addition adds permitted, conditioned square footage to your existing home — a new bedroom, a primary suite with bath, an expanded kitchen and family room, a home office, or a full second story. For most Los Angeles homeowners it is the alternative to moving: you keep your neighborhood, your schools and your property-tax basis, and you get the space your family actually needs.
American Reliable Construction & Remodeling designs, permits and builds additions across Los Angeles County — the San Fernando Valley, Westside, Burbank, Glendale and Pasadena — as a licensed California general contractor (CSLB #1155602), insured and BBB Accredited. Warranty available. Call for details.
Types of Home Additions We Build in Los Angeles
Bedroom and primary-suite additions
Ground-floor additions, usually to the rear or side yard, with a full bath and closet built to match the existing house.
Second-story additions
Adding a full or partial upper floor — the answer on small lots where setbacks block a ground-floor expansion.
Bump-outs and kitchen/family-room expansions
Pushing an exterior wall out 4–12 feet to open up a cramped kitchen or living area.
In-law and multi-generational suites
A bedroom, full bath and sitting area with its own entrance, designed for aging parents or adult children — distinct from an ADU because it stays part of the main house.
Garage additions and over-garage rooms
New garage space, or habitable rooms built above an existing or new garage structure.
Sunrooms and enclosed patios
Converting unconditioned patio and sunroom space into permitted, conditioned living area.
What a Room Addition Costs in Los Angeles
Ground-floor additions in Los Angeles County generally run about $350–$600 per square foot all-in — design, engineering, permits, foundation, framing, roofing, electrical, plumbing, HVAC, insulation, drywall and finishes — so a 400 sq ft bedroom-and-bath addition commonly lands between $140,000 and $240,000.
Second-story additions cost more — often $500–$800 per square foot — because the existing foundation, framing and roof must be engineered to carry the new load. Soft costs (architectural plans, structural engineering, Title 24 energy compliance, city plan-check and permit fees) typically add $10,000–$25,000.
Prices vary with soil and foundation conditions, hillside or fire-zone location, panel and sewer capacity, roofline complexity and finish level. We provide a free itemized estimate before any work begins.
Typical Los Angeles Room Addition Costs by Project
| Addition type | Typical size | Estimated range |
|---|---|---|
| Bedroom or home office (ground floor) | 200–300 sq ft | $70,000 – $180,000 |
| Bedroom + bathroom (ground floor) | 400 sq ft | $140,000 – $240,000 |
| Primary suite with bath and closet | 500–600 sq ft | $175,000 – $360,000 |
| Kitchen / family-room bump-out | 100–200 sq ft | $35,000 – $120,000 |
| Second-story addition | 800–1,000 sq ft | $400,000 – $800,000 |
Ranges are all-in estimates at $350–$600 per sq ft (ground floor) and $500–$800 per sq ft (second story) and exclude soft costs of roughly $10,000–$25,000. Every project receives a free, itemized written estimate.
What moves the number
- Foundation and soil conditions
- Hillside or fire-zone location
- Electrical panel and sewer capacity
- Roofline complexity
- Finish level
Permits and Zoning for Additions in LA
Every addition is a permitted project. In the City of Los Angeles it goes through LADBS; Burbank, Glendale, Pasadena, Beverly Hills, Santa Monica, Culver City and Calabasas each run their own building departments. Plan check reviews zoning (setbacks, lot coverage / floor-area ratio, height), structural calculations, Title 24 energy compliance, and — in hillside, very-high-fire-hazard and historic overlay zones — additional review. Requirements change from year to year, so we confirm current rules with your building department during feasibility.
- 1Feasibility and zoning check
- 2Architectural design and structural engineering
- 3Plan-check submittal and corrections
- 4Permit issuance
- 5Construction with staged inspections (foundation, framing, rough MEP, insulation, drywall, final)
- 6Certificate of occupancy / final sign-off
How Long a Room Addition Takes
Design and engineering take 4–8 weeks; plan check 6–16 weeks depending on jurisdiction; construction 3–5 months for a ground-floor addition and 5–8 months for a second story. Most families stay in the house during a ground-floor addition; second-story work often requires moving out for part of the build because the roof comes off.
Addition vs. ADU vs. Moving
Room addition
Adds space to the main house and shares its systems. Best for families who need more bedrooms, bathrooms or living area.
ADU
A separate unit with its own kitchen and entrance. Best for rental income or independent family living — see ADU construction and garage conversion.
Moving
Worth comparing against Los Angeles transaction costs and the loss of a low property-tax basis on the home you already own.
Why Los Angeles Homeowners Choose American Reliable for Additions
- One licensed contractor for design, permits and build
- One project manager and a written schedule
- Itemized estimates before any work begins
- Permits and inspections handled under our license
- Crews that match the existing home — roofline, stucco, siding and trim — so an addition does not look bolted on
- Multi-generational living is a specialty
Planning an addition in the Valley? Read our guide to room additions in Sherman Oaks.
Room Addition FAQs — Los Angeles
How much does a room addition cost in Los Angeles?
Ground-floor additions in Los Angeles County generally run about $350–$600 per square foot all-in, so a 400 sq ft bedroom-and-bath addition commonly lands between $140,000 and $240,000. Second-story additions often run $500–$800 per square foot because the existing foundation, framing and roof must be engineered to carry the new load. Soft costs — architectural plans, structural engineering, Title 24 compliance and city plan-check and permit fees — typically add $10,000–$25,000. Prices vary with soil and foundation conditions, hillside or fire-zone location, panel and sewer capacity, roofline complexity and finish level. We provide a free itemized estimate before any work begins.
Do I need a permit for a room addition in LA?
Yes. Every addition is a permitted project. In the City of Los Angeles it goes through LADBS; Burbank, Glendale, Pasadena, Beverly Hills, Santa Monica, Culver City and Calabasas each run their own building departments. We prepare the plans, submit them, respond to plan-check corrections and carry the job through every inspection under our license. Requirements change from year to year, so we confirm current rules with your building department during feasibility.
Is a second-story addition possible on my house?
It depends on the existing foundation and framing, which a structural engineer evaluates before design is finalized. Second stories are often viable on single-story ranch homes, though the project may require foundation reinforcement and upgraded framing to carry the new load. We check this during feasibility rather than discovering it mid-project.
How long does a room addition take?
Design and engineering take about 4–8 weeks, plan check 6–16 weeks depending on the jurisdiction, and construction 3–5 months for a ground-floor addition or 5–8 months for a second story. Most families stay in the house during a ground-floor addition; second-story work often requires moving out for part of the build because the roof comes off.
Will an addition increase my property taxes?
The new square footage is typically reassessed as new construction while the existing home keeps its original basis. Confirm the specifics for your property with the Los Angeles County Assessor — we do not give tax advice.
Room addition or ADU — which is better?
It depends on your goals. If you need connected family space — more bedrooms, a bath, a larger living area — an addition is usually the right answer. If you want rental income or independent living with a separate kitchen and entrance, an ADU is the better fit. We evaluate both options with you during the free estimate.
Free Room Addition Estimate in Los Angeles
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American Reliable Construction & Remodeling, Inc. is a licensed, bonded and insured California general contractor (CSLB #1155602) based in Sherman Oaks. Tell us about the project; we'll walk the property with you and put a detailed, itemized estimate in writing — no obligation.
- Call toll-free(877) 702-6180
- Emailinfo@americanreliablela.com
- Office15260 Ventura Blvd #1200, Sherman Oaks, CA 91403
- Hours (Pacific)Sunday – Thursday: 8:00 AM – 7:00 PMFriday: 8:00 AM – 3:00 PMSaturday: Closed
- CredentialsCSLB #1155602 · Licensed, bonded & insured · BBB Accredited (A-)5.0 on Google · 22 reviews
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