Built from Los Angeles building permits, not from a national average.
3,702 permits·Los Angeles·2021 to 2023
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What 3,702 Los Angeles permits actually say
The calculator above prices your specific build. This is the market around it: what homeowners actually declared to the City of Los Angeles when they pulled an ADU permit. Garage conversions are excluded here, they sit in their own distribution and are far cheaper.
What 3,702 Los Angeles permits declared
The cheapest tenthSmall, simple, often a single room$52,000
A quarter file underModest footprint, straightforward build$75,000
The median projectWhat a typical filing declares$110,000
A quarter file overLarger, or a kitchen or bath inside it$150,000
The top tenthStructural work or a high finish level$200,000
Declared construction value on adu permits filed in Los Angeles, 2021-01 to 2023-05. This is what the applicant files for fee purposes, so a contractor quote for the same work runs higher.
The direction of travel
In 2021, 1,096 filings carried a median of $102,111. In 2022, 1,871 filings carried a median of $110,000. In 2023, 735 filings carried a median of $120,000. That is a rise of 18% across the window, on filings rather than on quotes.
Declared valuation is the figure the applicant files for fee calculation. It sits below the all-in price: design, permit fees, financing and most finish upgrades are not in it.
Coverage runs to May 2023, the last date in the published dataset.
Los Angeles filings only. Do not read these levels across city lines, fee practice differs by jurisdiction.
3 California ADU builders, editor-screened. 4 questions.
Across 3,702 Los Angeles ADU permits filed between 2021 and May 2023, excluding garage conversions, the median declared construction value was $110,000. A quarter came in under $75,000 and a tenth ran past $200,000. Declared value is filed for fee calculation and sits below the all-in price, which adds design, permit fees, utility connections and financing.
Is converting the garage cheaper than building a new ADU?
Substantially. Garage conversion permits in the same dataset carry a median declared value of $40,000 against $110,000 for a new build, because the slab, walls and roof already exist. The trade is size and layout: a conversion inherits the garage footprint, a new build does not.
Has the cost of building an ADU gone up?
On filings, yes. The median declared value moved from $102,111 in 2021 to $120,000 in 2023, about 18% across the window, while the number of permits filed nearly doubled between 2021 and 2022. That is demand and cost rising together.
What drives the difference between a $75,000 ADU and a $200,000 one?
Square footage matters less than three other things: whether the unit is detached or attached, how far the utility connections have to run, and the finish level of the kitchen and bathroom. Site access is the quiet one. A backyard a truck cannot reach adds cost to every phase.
