Statistics
Garage conversion statistics
39 of 44 figures are HyreADU calculations. How common the conversion is, what it is declared at, how big it ends up, and how often it finishes — measured on 39,279 Los Angeles permits.
Written by HyreADU Research Desk Primary-source research and data analysis
Audited by HyreADU Research Desk Provenance and citation audit
How to use this page
In the City of Los Angeles, 19,294 of 39,279 ADU-adding building permits issued between 1 January 2020 and 2026-08-30 — 49.1% — carry a work description that describes converting a garage. The conversion is not a niche route.
On the only complete permit file in California that carries a departmental ADU flag, it is roughly half of everything.
And it is stable. The share sits between 38% and 61% in every year of the window, so it is not a phase the market is passing through.
It is the small lane and the cheap-on-paper lane. Median declared valuation is $48,000 against $96,000 on every other ADU permit (2.00×), and median permitted floor area is 480 sq ft against 890 sq ft. A declared valuation is a fee input, not a construction cost, and we treat it that way throughout — the valuation study explains why the two diverge.
It is also the lane that finishes. 67.8% of conversion permits in the frame have reached a certificate of occupancy or a permit final, against 59.5% of everything else — a gap of 8.3 percentage points.
39 of 44 figures on this page are HyreADU calculations (39 hyreadu calculation, 4 agency published, 1 trade / survey estimate). This is a Los Angeles number and nothing else. There is no California garage-conversion share on this page, because no California file supports one.
And a garage that is legal to park in is not a garage that is legal to sleep in: fire separation, egress, ceiling height, slab and foundation work, a service upgrade, and alarms are what close that gap, and a plan checker exists to look at all of it.
Read the provenance, not just the number
Every figure below is one of three things, and the row says which.
HyreADU calculation — we downloaded the Los Angeles permit extract, framed it on the department’s own ADU flags, classified the work description, and computed the share, percentile or ratio ourselves.
The method and its failure modes are on the garage-conversion study.
Agency published — a statutory provision quoted from the Government Code. We cite the section, not an article about the section.
Trade / survey estimate — Chapple, Ganetsos and Lopez’s 2021 owner survey. A survey of a 2018–19 cohort, labeled as what it is.
Where the classifier can be wrong. The ADU frame is the department’s: adu_changed and junior_adu are LADBS fields.
The garage classification is not — it is our keyword read of the department’s free-text work_desc. A permit that converts a garage but does not say so is missed.
A permit that mentions a garage while doing something else to it can be caught.
We publish the share to one decimal place and label it as ours precisely because it is a classification, not a count.
Why the geography column never widens. Los Angeles is the only California jurisdiction this desk has found that publishes a departmental ADU flag on a complete permit extract. HCD’s Annual Progress Report counts ADU units statewide but has no conversion category.
So a California conversion share does not exist in any file we can reach, and we would rather say that than compute one from a single city and hope nobody checks.
The figures most worth knowing
Full method, classifier rules and limitations on the garage-conversion study.
How common, year by year
If the conversion were a response to a temporary condition — a construction-cost spike, a financing window — the share would move. It does not. Across seven years of issue it stays inside a 23-point band while the absolute number of ADU permits roughly doubles.
| Year of issue | Conversion permits | All ADU permits | Conversion share | Class |
|---|---|---|---|---|
| 2020 | 2,045 | 3,373 | 60.6% | HyreADU calculation |
| 2021 | 2,819 | 5,072 | 55.6% | HyreADU calculation |
| 2022 | 3,740 | 7,120 | 52.5% | HyreADU calculation |
| 2023 | 2,992 | 6,158 | 48.6% | HyreADU calculation |
| 2024 | 3,018 | 6,394 | 47.2% | HyreADU calculation |
| 2025 | 3,091 | 6,933 | 44.6% | HyreADU calculation |
| 2026 | 1,589 | 4,229 | 37.6% | HyreADU calculation |
All rows are HyreADU calculations over the LADBS extract. Frame total 39,279 permits; 19,294 classified as conversions; 49.1% overall. 2026 covers part of the year only.
The pipeline from permit to occupancy — which is where this stability starts to matter — is on the permits-versus-completions study.
The cheap lane on paper, the small lane in fact
Two distributions from the same file, one for conversion permits and one for everything else. The gap is real and it is large — but the left-hand column is a declared valuation, which is what a fee is computed from, not what the job costs.
| Measure | Garage conversion | Every other ADU permit | Ratio | Class |
|---|---|---|---|---|
| n, declared valuation | 19,286 | 19,964 | — | HyreADU calculation |
| 10th percentile valuation | $20,000 | $20,000 | 1.00× | HyreADU calculation |
| 25th percentile valuation | $30,000 | $47,000 | 1.57× | HyreADU calculation |
| Median valuation | $48,000 | $96,000 | 2.00× | HyreADU calculation |
| 75th percentile valuation | $75,000 | $150,000 | 2.00× | HyreADU calculation |
| 90th percentile valuation | $102,457 | $272,000 | 2.65× | HyreADU calculation |
| n, permitted floor area | 17,937 | 15,001 | — | HyreADU calculation |
| 25th percentile floor area | 373 sq ft | 586 sq ft | 1.57× | HyreADU calculation |
| Median floor area | 480 sq ft | 890 sq ft | 1.85× | HyreADU calculation |
| 75th percentile floor area | 745 sq ft | 1,200 sq ft | 1.61× | HyreADU calculation |
| 90th percentile floor area | 1,193 sq ft | 1,818 sq ft | 1.52× | HyreADU calculation |
| Implied declared valuation per sq ft, at the medians | $100 | $108 | 1.08× | HyreADU calculation |
Percentiles are HyreADU calculations over the LADBS valuation and square_footage fields. The per-square-foot row is the ratio of the two medians and is published as an implied declared figure — it is not a construction rate, and it should not be used as one.
A single standalone comparison of the two routes lives in the garage conversion versus new build tool.
Why declared valuation understates a conversion in particular. The fee-relevant value is the work described on the permit.
Fire separation, egress, alarms and a panel upgrade may be split across trade permits; the slab, the foundation and the driveway may not be in this line at all.
That structure pushes the conversion lane down relative to a single new-build permit that carries everything. Read the valuation study before quoting either column as a price.
What kind of permit a conversion actually is
Permit type is the tell that a conversion is a legal reclassification rather than a construction project. Almost none of it is filed as new construction, because from the department’s point of view the building already exists.
| Permit type | Conversion permits | Share of conversions | Class |
|---|---|---|---|
| Bldg-Alter/Repair | 11,491 | 59.6% | HyreADU calculation |
| Bldg-Addition | 7,793 | 40.4% | HyreADU calculation |
| Bldg-New | 10 | 0.1% | HyreADU calculation |
Across the whole ADU frame the department issued 10,612 new-construction permits, 12,227 additions and 16,439 alteration or repair permits. The conversion lane accounts for almost none of the first category and most of the third.
This matters for how the numbers should be read. An alteration permit’s square_footage can describe the scope of work rather than the finished unit, which is why every floor-area headline on the size digest is drawn from new construction only.
The lane that finishes
A permit is an intention. What separates the two lanes most usefully is not price or size but whether the department ever signed the job off.
| Group | Share reaching a certificate of occupancy or permit final | Class |
|---|---|---|
| Garage conversion permits | 67.8% | HyreADU calculation |
| Every other ADU permit | 59.5% | HyreADU calculation |
| Whole ADU frame | 63.6% | HyreADU calculation |
| Gap in favor of conversions | +8.3 percentage points | HyreADU calculation |
Computed from the department’s cofo_date and status_desc fields. This is a rate over a window, not a cohort survival rate: a permit issued in 2026 has had far less time to finish than one issued in 2020, and both are in the denominator.
The comparison between the two lanes is still meaningful because both are subject to the same censoring.
Do not read this as “conversions are easier”. A shorter, cheaper, smaller job finishing more often is unsurprising.
What it does say is that the conversion route converts intention into occupied housing at a higher rate than the alternative, which is the number that matters for housing supply. Statewide permit-to-completion behavior is on the completions study.
Where the conversion is the dominant route
The conversion share is above 40 per cent in every area planning commission in the city, and the spread between the highest and the lowest is 12.0 points. This is one municipal code and one state statute producing seven different mixes, because the housing stock differs.
| Area planning commission | Conversion permits | All ADU permits | Conversion share | Class |
|---|---|---|---|---|
| North Valley | 5,106 | 9,764 | 52.3% | HyreADU calculation |
| South Valley | 5,850 | 11,379 | 51.4% | HyreADU calculation |
| Central | 1,649 | 3,274 | 50.4% | HyreADU calculation |
| South Los Angeles | 3,083 | 6,297 | 49.0% | HyreADU calculation |
| West Los Angeles | 1,837 | 4,197 | 43.8% | HyreADU calculation |
| Harbor | 420 | 1,022 | 41.1% | HyreADU calculation |
| East Los Angeles | 1,349 | 3,346 | 40.3% | HyreADU calculation |
All rows are HyreADU calculations over the LADBS extract. North Valley runs highest at 52.3%; East Los Angeles lowest at 40.3%. The two Valley commissions alone account for 10,956 of the 19,294 conversion permits in the file.
The same file split by floor area rather than route is on the size digest, where the Valley is also where the largest units are built.
Figures we will not repeat
- A national or statewide “garage conversions are X% of ADUs”
We have a Los Angeles share of 49.1% because Los Angeles publishes a permit extract with a departmental ADU flag and a free-text work description. HCD’s Annual Progress Report has no conversion category.
The Census Building Permits Survey has no ADU category at all, and a garage conversion is frequently not counted in it as new residential construction. So there is no California figure to quote, and we will not derive one from one city.
- A declared valuation quoted as a garage conversion cost
$48,000 is the median value declared on the permit for fee purposes. It is not a contract price, it excludes work carried on separate trade permits, and the incentive structure around it is not neutral.
Anyone publishing it as “the cost of a garage conversion in Los Angeles” has changed what the number means. The valuation study exists to stop us doing that.
- The classifier presented as a departmental count
LADBS flags ADUs. LADBS does not flag garage conversions. The conversion classification on this page is HyreADU’s keyword read of a free-text field, and it will both miss and over-catch. Every row carrying it says HyreADU calculation. A citation that attributes the conversion share to the City of Los Angeles is wrong.
- Any instruction on how to convert a garage
A garage that is legal to park in is not a garage that is legal to sleep in.
Fire separation from the remaining garage or the house, a compliant egress opening, ceiling height, slab and foundation condition, electrical service capacity, and smoke and carbon-monoxide alarms are the work that closes the gap — and every one of them is a plan-check and inspection question, not a statistics question.
This page counts permits. It does not tell anyone how to build.
Citing these figures
Journalists and planning desks are welcome to cite these tables. Link the garage-conversion study rather than this digest: the classifier, the frame rules and the limits live there.
Where a figure is labeled HyreADU calculation, attribute it to HyreADU and name the file — “HyreADU analysis of the Los Angeles Department of Building and Safety permit extract pi9x-tg5x, 39,279 ADU-adding permits, 2020–2026.” Where it is Agency published, cite the Government Code section. Corrections go on the page with a dated note: hello@hyreadu.com.
Carry the two qualifiers. It is one city, and the conversion classification is ours rather than the department’s. Both fit in a sentence, and dropping either turns a measurement into a claim.
Questions
How common are garage conversion ADUs?
How much does a garage conversion cost?
How big is a converted garage ADU?
Is a garage conversion more likely to actually get built?
Do I have to replace the parking I lose?
Why is almost no conversion filed as new construction?
What about a garage that was already converted without a permit?
Where does this data come from, and can I check it?
adu_changed and junior_adu flags, dropped supplemental permits by permit-number segment, and classified the department’s work_desc text for garage language. Every rule is written out on the garage-conversion study, and you can download the same file.Written and audited by
HyreADU Research Desk
Primary-source research, data analysis and fact checking
We are a research desk, not a builder. We read the permit extract, the statute, the HCD return or the fee schedule ourselves, and publish each figure with its source and retrieval date.
Where a number cannot be traced to a primary source, we leave it out and say what we could not verify. Our store-based claims cover California only.
- CA
- the only state this desk will make store-based claims about
- 5
- jurisdictions with extracted ADU permit evidence
- 735
- CSLB-verified companies in the California store
- 0
- national claims from a one-state store
How this desk works
- Primary sources only. Permit counts come from the city or county that issued the permit. Production counts come from HCD’s Annual Progress Report. Rents come from HUD or the Census. We do not cite an article that cites a source; we download the source and compute the figure ourselves.
- This is a California site. The company store is 734 California firms and one New Mexico firm. Permit evidence exists for five named jurisdictions: Los Angeles, San Francisco, Sacramento, San José and unincorporated Marin. A number from that store is titled to those places, never to the United States.
- A permit is not a completion, and a license is not an ADU grade. California licenses no ADU classification. Being named on an ADU permit is evidence of engagement in that jurisdiction, not of quality, completion, or work anywhere else. Owner-builder permits are excluded from contractor counts.
- Calculation is labeled as calculation. Figures we derive are never presented as something HCD, HUD, the Census or a city published. Terner Center research is cited as Terner’s, never restated as ours.
- We do not design, permit or build ADUs, and we take no payment for placement, ranking or a favorable mention. Pages that look like rankings are not: they publish public-record counts and let the reader decide.
- Nothing here is legal, tax or financial advice. Zoning, underwriting and appraisal practice vary by jurisdiction, lender and appraiser. The useful next step on a specific lot is the planning counter and a licensed professional.
Data as of LADBS Socrata resource pi9x-tg5x (409,619 rows) analyzed 2026-09-05, departmental refresh to 2026-08-30; Government Code §§ 66311.5, 66313, 66314 and 66323 retrieved 2026-09-05. Authorship on this site is organizational: the analysis belongs to the desk rather than to a named individual, and we do not publish credentials we do not hold.
Our editorial policy sets out how we source, date and correct what we publish.
Sources & retrieval dates
- City of Los Angeles Department of Building and Safety — Building Permits Issued from 2020 to Present (Socrata resource pi9x-tg5x) , Full resource download, 409,619 rows, retrieved 2026-09-05; departmental refresh field to 2026-08-30. Fields used: permit_nbr, permit_type, issue_date, cofo_date, status_desc, valuation, square_footage, work_desc, apc, adu_changed, junior_adu. The ADU frame is the department’s flags; the garage classification is HyreADU’s keyword read of work_desc. Retrieved 2026-09-05.
- California Government Code § 66314 — the standards a local ADU ordinance may impose , The treatment of existing accessory-structure space, the size ceilings, and the parking provisions relevant to a converted garage. Retrieved 2026-09-05.
- California Government Code § 66323 — ministerial approval of a qualifying ADU , The provision that makes a conforming application a plan-check question rather than a discretionary one. Retrieved 2026-09-05.
- California Government Code § 66313 — definitions, including the 500 square foot junior ADU , Amended by SB 543 (Stats. 2025, Ch. 520), operative 1 January 2026. Retrieved 2026-09-05.
- California Government Code § 66311.5 — impact fees and the 750 square foot threshold , Added by renumbering § 66324 by Stats. 2025, Ch. 520 (SB 543), operative 1 January 2026. Relevant because most conversions fall under the threshold. Retrieved 2026-09-05.
- SB 543 (McNerney, 2025) — Accessory dwelling units. Stats. 2025, Ch. 520 , The second recodification of the ADU chapter in under two years. Renumbers § 66324 to § 66311.5, § 66327 to § 66313.5 and § 66332 to § 66311.7 from 1 January 2026. Cited because guidance on unpermitted garage conversions almost universally still cites § 66332. Retrieved 2026-09-05.
- Chapple, Ganetsos and Lopez, Implementing the Backyard Revolution (UC Berkeley Center for Community Innovation, 22 April 2021) , 51 per cent of new California ADUs generating rental income, in a survey of owners of units permitted or completed in 2018–19. Cited as theirs. Retrieved 2026-09-05.
Half the permits, and none of the shortcuts
A conversion is the most common ADU permit in Los Angeles and the one most likely to finish. It is still fire separation, egress, ceiling height and service capacity — decided by a plan checker, not by a statistic.
HyreADU does not design, permit or build accessory dwelling units. Statistics are informational. They are not legal, construction or land-use advice, and nothing here is an instruction to convert a garage or an assurance that any conversion is permittable.
Every figure labeled as a HyreADU calculation is a measurement of City of Los Angeles building permit records and describes no other jurisdiction. The garage classification is HyreADU’s reading of a free-text departmental field, not a departmental count.
Declared permit valuation is a fee input, not a construction cost. Statutory text was retrieved on the date shown; California ADU law was recodified twice between 2024 and 2026 and section numbers change.