Room addition cost in Los Angeles, 2026.
What Los Angeles homeowners actually pay for room additions in 2026 — from ground-floor bump-outs to full second-story additions.
Where the money goes.
| Category | Low | High | Notes |
|---|---|---|---|
| Bump-out (100–250 sq ft) | $60,000 | $120,000 | Extends kitchen, bedroom, or family room |
| Master suite addition | $120,000 | $200,000 | Bedroom, walk-in closet, and bath |
| Second-story addition | $180,000 | $300,000 | Adds significant square footage; requires structural analysis |
| Design and structural engineering | $5,000 | $15,000 | $5,000 – $15,000 |
| Permits and inspections | $2,000 | $7,000 | $2,000 – $7,000 |
| Foundation and site work | $10,000 | $35,000 | $10,000 – $35,000 |
| Framing and roofing | $20,000 | $50,000 | $20,000 – $50,000 |
| Electrical, plumbing, HVAC | $10,000 | $30,000 | $10,000 – $30,000 |
| Windows and exterior doors | $5,000 | $18,000 | $5,000 – $18,000 |
| Interior finishes | $15,000 | $40,000 | $15,000 – $40,000 |
| Exterior finishes | $8,000 | $25,000 | $8,000 – $25,000 |
Cost FAQs.
- How much does a room addition cost per square foot in Los Angeles?
- Most room additions cost $300 to $600 per square foot, with second-story additions on the higher end.
- What is the most expensive part of a room addition?
- Foundation work, structural engineering, and roof tie-in are typically the largest expenses.
- Do room additions require permits in Los Angeles?
- Yes. All room additions require building permits, and many require planning or design review.
- Can I add a second story to my Los Angeles home?
- Often yes, but it depends on the existing foundation, structure, zoning, and local height limits. A structural engineer must evaluate feasibility.
- Does CaliFirst Remodel build room additions in Los Angeles?
- Yes. CaliFirst Remodel designs and builds room additions throughout Los Angeles.
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