2026 cost guide · Los Angeles, CA
How much does it cost to build a home addition in Los Angeles, CA?
Typical range for an addition onto an existing home
$174,000 – $377,000
About $522/sq ft midrange across 500 sq ft. Los Angeles, CA indexes at ×1.45 versus the national building-cost average — a city-level match in our cost index.
These figures come from the same estimating engine we use to price a real project — the local cost index for Los Angeles, CA is baked in, not a national average with your city's name pasted on top. The number that matters is your project’s, though: finish level, site, and scope move it more than geography does. Get your exact home addition estimate →
Home addition cost by finish level in Los Angeles, CA
Starter / builder-grade
$348/sq ft
$174,000
Midrange
$522/sq ft
$261,000
High-end / custom
$754/sq ft
$377,000
Based on 500 sq ft, a typical size for an addition onto an existing home. Your size and scope change the total — run your own numbers.
What goes into a home addition estimate
- •Site work, foundation & structure — the parts you never see but pay for first
- •Framing, roofing & the weather-tight shell
- •Mechanical, electrical & plumbing systems
- •Interior finishes — the single biggest swing in the whole budget
- •Permits, plan review & local fees
- •General conditions, contractor overhead & contingency
Get your exact Los Angeles, CA estimate
Line-by-line costs for your specific project + a builder-ready brief. Free — no account, no card to see your number.
Estimate my home addition →Los Angeles, CA home addition cost — FAQ
How much does it cost to build a home addition in Los Angeles, CA?
A typical an addition onto an existing home in Los Angeles, CA runs about $174,000 to $377,000 — roughly $348–$754 per square foot across 500 sq ft. Los Angeles, CA indexes at ×1.45 versus the national building-cost average — a city-level match in our cost index.
What is the cost per square foot to build a home addition in Los Angeles, CA?
Expect about $348/sq ft at a starter finish level, $522/sq ft midrange, and $754/sq ft for high-end custom work. Your exact rate depends on finish level, site conditions, and design complexity.
What drives the price up or down?
Finish level is the biggest lever, followed by site and access, structural complexity, and (for a remodel or addition) how much of the existing structure you keep. Local permit fees and labor availability move the total as well.
How do I get an exact estimate for my project?
Answer a few questions about your project and get a free, itemized estimate — line by line, with a builder-ready brief — in a few minutes. No account or payment required to see your number.
Other projects in Los Angeles, CA
Home addition costs in other cities
- Home addition cost in San Francisco, CA →
- Home addition cost in San Diego, CA →
- Home addition cost in San Jose, CA →
- Home addition cost in Oakland, CA →
- Home addition cost in Sacramento, CA →
- Home addition cost in Monterey, CA →
- Home addition cost in Santa Barbara, CA →
- Home addition cost in Austin, TX →
- Home addition cost in Dallas, TX →
- Home addition cost in Houston, TX →
Estimates are engine-generated planning figures for Los Angeles, CA, not a quote. Actual pricing depends on your design, site, and builder. All cost guides.