Room addition cost in Los Angeles (2026).
Real price ranges from Pacific ProWorks for bedroom additions, master suites and second stories, plus plans and engineering.
Estimates only — your price is set in writing.
Figures on this page are typical ranges from recent Los Angeles projects, shown to help you plan. They are not a quote or an offer. Your price is fixed only in a signed contract after a site visit, and it depends on scope, site conditions, finish level and current material costs. City permit and inspection fees are paid by the homeowner. Offers have terms and some cannot be combined.
What a home addition costs.
| Option | Typical price* | Details |
|---|---|---|
| 300 sq ft bedroom + bath | $85,000–$120,000 | Single-story addition |
| 600 sq ft master suite / family room | $165,000–$240,000 | Single-story addition |
| Second story, 800–1,000 sq ft | $240,000–$400,000+ | Structure, stairs and tie-ins |
| Per square foot | $275–$400 / sq ft | Typical range |
*Rough ranges from recent Los Angeles projects, price list as of October 2026. Not a quote.
Build your own addition estimate.
Pick the size and extras you want, see a rough price range right away, then send your picks for a free site visit.
Plans and engineering for additions.
| Plans | Price | Includes |
|---|---|---|
| Addition plans | $7,500–$9,000 | Architectural, structural and Title 24 |
| Addition + ADU plans | $14,000–$18,000 | Architectural, structural and Title 24 |
Plans include up to one change after they are fully drawn. Soil or geological reports (hillside lots only) are not included.
What moves the price.
Tie-ins to the existing house, foundation work, load-bearing walls, plumbing and electrical runs, and site access for staging.
How long an addition takes.
Most additions take 4–8 months of construction, after plans and city permits.
Addition cost FAQ.
Step 1 — pick a topic. Step 2 — click a question.
How much does a room addition cost in Los Angeles?
Typically about $275–$400 per square foot: $85,000–$120,000 for a 300 sq ft bedroom and bath, and $165,000–$240,000 for a 600 sq ft master suite or family room.
How much do addition plans cost?
About $7,500–$9,000 for architectural plans, structural engineering and Title 24 energy calculations.
How long does an addition take?
Usually 4–8 months of construction, after plans and permits.
Is this a quote?
No. These are rough ranges for planning only. Your price is set in a written contract signed by you and Pacific ProWorks Inc. after a free site visit.
Are city permit fees included?
No. City permit, plan-check and inspection fees are paid by the homeowner and are not included in these ranges.
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