Room Addition Cost in Los Angeles
The median declared permit valuation was $75,000 for one- and two-family homes in the City of Los Angeles over the last 12 months; it is not a contract price.
Los Angeles at a glance
- Median declared permit valuation, room addition permits on one- and two-family homes, City of Los Angeles, last 12 months
- $75,000
- Issued room addition permits, all property types, City of Los Angeles, last 12 months
- 1,634 permits
- Share of issued room addition permits on one- and two-family homes, City of Los Angeles, last 12 months
- 99.9%
LA Department of Building and Safety, Building Permits Issued 2020 to Present (data.lacity.org) · data as of
- Numbers from LADBS public records
- Up to three local contractors, never a long list
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A useful first step
Before you start in Los Angeles
Confirm whether your scope needs plan check or an express permit.
What to prepare
LADBS offers express permits for some simpler work. Larger or more complex changes can require plan review. Describe the actual work, including structural, electrical and plumbing changes, when asking the department which route applies.
LADBS contractor guide · Checked
What do permits say a room addition costs?
From City of LA building permits, last 12 months. Not a contract price. How we calculate this
Declared values on City of Los Angeles building permits, last 12 months. A declared value is what the permit states, not your contract price. How we calculate this.
Source: LA Department of Building and Safety, Building Permits Issued 2020 to Present (data.lacity.org), permits on one- and two-family homes issued to ; fire rebuilds excluded. ZIP medians need 20+ permits.
Room addition permit figures, City of Los Angeles
Room addition permit figures, City of Los Angeles
Local numbers for Los Angeles, each with its source and date.
- Median days from submission to permit issue, one- and two-family homes, City of Los Angeles, last 12 months1
- 105 days
| Year | Count |
|---|---|
| 2020 | 1,632 |
| 2021 | 2,095 |
| 2022 | 2,432 |
| 2023 | 1,995 |
| 2024 | 2,010 |
| 2025 | 1,897 |
Source: LA Department of Building and Safety, Building Permits Issued 2020 to Present (data.lacity.org), full calendar years, fire rebuilds excluded, data as of .
Room addition declared permit valuation, City of Los Angeles
| Project | Figure | Range on a shared scale |
|---|---|---|
| Median declared permit valuation, room additions on one- and two-family homesA declared value on a building permit, not the full project cost. Usually below what a room addition costs. | $75,000 |
Bars share one scale, from $0 to $75,000.
The figure is the median declared value on City of Los Angeles building permits for one- and two-family homes over the last 12 months. It is the value the applicant declared to the city, not a contract price, and it is usually below the real project cost. Get an estimate for your home.
Planning your project
$75,000 is the median declared permit valuation for room addition permits on one- and two-family homes in the City of Los Angeles over the last 12 months. It is the figure the applicant declared to the city, not what a room addition costs.
What a declared valuation is
The declared valuation is the amount written on the building permit. It is usually below the real project cost, so treat it as a starting point only.
What adds to the real cost
Design, materials, finishes, the condition of the existing house and work that is not on the permit all add to the price. Every project is different.
How to know your number
An estimate for your home is the way to know. Describe your addition and a local builder who receives your request can give you a figure for your project.
Room addition cost questions
Is the permit valuation the real cost of a room addition?
No. The $75,000 figure is the median declared value on City of Los Angeles permits for one- and two-family homes over the last 12 months. It is what the applicant declared to the city, and it is usually below the real project cost.
What drives the price of a room addition?
Design, materials, finishes, labor, the condition of the existing house, and work that is not on the permit all affect the price. The size and layout of your plans matter too.
Why do estimates for room additions differ?
Each builder prices the work in a different way, and each home starts from a different place. A figure based on your plans and site is more useful than a citywide median.
How do I get a reliable number for my project?
Share your plans, your goals and what you want the finished space to include. A local builder who receives your request can give you an estimate for your home. You can also check any contractor's license status with the CSLB.
Does a room addition need a permit in the City of Los Angeles?
Ask your builder which permits your project needs. The City of Los Angeles issued 1,634 room addition permits over the last 12 months, and 99.9% of them were on one- and two-family homes.
How long does a room addition permit take to issue?
In the City of Los Angeles, the median time from submission to permit issue was 105 days over the last 12 months for one- and two-family homes. Your timeline depends on your plans and the city's review.
Recent work by a contractor in our network
Photos from the contractor's own projects, used with permission. Captions name the type of work.
Whole-home remodel, exterior 
Kitchen, whole-home remodel 
Addition / ADU interior 
Addition / ADU interior 
Whole-home remodel 
Whole-home remodel
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