Research study
How long do ADU builders last? What the license register says
You sign a six-figure contract and the workmanship warranty runs for years. This measures how often the license on the other side of that contract is still standing — and it names nobody.
Written by HyreADU Research Desk Primary-source research and data analysis
Audited by HyreADU Research Desk Scope-of-claim and identifiability review
The finding
Of 965 distinct Contractors State License Board licenses held by firms named as contractor of record on ADU permits at two or more separate addresses in five California jurisdictions, 738 — 76.5% — were “current and active” when the board’s own record was read on 29–30 August 2026. 227, or 23.5%, were something else. “Something else” is not one thing, and lumping it together is the mistake this page exists to avoid. 86 licenses were expired, 52 revoked, 44 suspended, 28 canceled and 16 inactive.
Expired and canceled are ordinary: a license expires if it is not renewed, and “LICENSE CANCELED PER REQUEST” appears 1 times in the register entries we read.
The single most common miscellaneous entry across the whole frame is “LICENSE REISSUED TO ANOTHER ENTITY”, 138 times — that is a firm reorganising, not a firm failing.
Older licenses are not more fragile; if anything the reverse. Licenses first issued before 2000 show 21.5% not current and active. Those first issued in 2015–2019 — the ADU boom cohort — show 28.8%, the highest of any cohort with more than 100 licenses in it.
Median license age across the frame is 14.8 years. And larger operators are not obviously safer either. Among firms named at 10 or more ADU sites, 72.5% were current and active; among those named at exactly 2, 76.2%. On this frame, size buys very little.
Read the shape of this measurement before you read the number. It is a snapshot of a register on one date, not a cohort followed through time, so it is not a survival rate and we do not call it one.
The frame is contractors who did enough ADU work in five specific cities to appear twice, which is not a sample of California contractors.
And a license status is a license status: it is not a grade, not a verdict about workmanship, and not evidence about anything the firm did on any particular job. This page names no company.
Read this first — this is the page where it matters most
- No company is named on this page, and that is deliberate
Everything here is an aggregate of a public register. We publish no list of firms whose licenses lapsed, no ranking, and no company-level status.
A homeowner who wants to check a specific contractor should look that contractor up on the board’s own Check a License service, where the record is authoritative, current and complete — which our snapshot is not.
Building a “failed builders” list from a status field would be neither research nor fair.
- A lapsed license has many innocent causes
Retirement. A sale. A move from sole ownership to a corporation, which produces a new license number and cancels the old one. A renewal in process. Death.
The register itself says so: “LICENSE REISSUED TO ANOTHER ENTITY” appears 138 times, “SECRETARY OF STATE - DISSOLUTION” 18 times and “LICENSE CANCELED PER REQUEST” 1 times in the entries we read.
Not one of those is a statement about the quality of anybody’s work.
- This is a snapshot, not a survival curve
We read the register once, on 29–30 August 2026, and we know when each license was first issued. We did not follow a cohort of firms forward through time and record when each one stopped.
That means we can say what share of a given issue cohort is currently not active; we cannot say what share of firms that were active in 2020 are gone by 2026, and we will not phrase it that way.
Anybody who wants that measure needs the register at two dates, and we hold it at one.
- The frame is not a sample of California contractors
A license enters this frame only if the firm was named as contractor of record on ADU permits at two or more distinct addresses in one of five jurisdictions — Los Angeles, San Francisco, Sacramento, San José or unincorporated Marin — and holds a B or B02 classification.
That selects for firms doing repeat ADU work in five specific places. It excludes owner-builders entirely, excludes anybody who did exactly one ADU, and excludes the rest of California.
It is not a random sample and no share on this page generalises to “California contractors”.
- A license status today says nothing about the license status then
A firm whose license is expired in August 2026 may have been current and active, bonded and insured on every day it worked. The permit dates in this frame run back years.
Reading a 2026 status backwards onto a 2021 job is a mistake, and it is the single most likely way this page could be misused.
- And a license is not an ADU grade
California licenses no ADU classification. A B license is a general building license. Being named on an ADU permit is evidence of engagement in that jurisdiction — not of quality, not of completion, and not of work anywhere else.
Why this is worth measuring at all
An ADU contract is unusual in domestic construction. It is large — frequently the second largest transaction a household ever signs — it runs for a long time, and the obligations that matter most to the homeowner start when the work finishes rather than when it starts.
A workmanship warranty, a latent-defect claim, a callback on a roof or a shower pan: all of those require a counterparty who still exists.
California backs part of that with a bond. Every license in this frame that publishes a bond amount publishes one of two figures: 779 carry a $25,000 contractor’s bond and 61 carry $15,000.
On a $250,000 ADU, a $25,000 bond is ten cents on the dollar, and it is not a warranty fund — it is a limited pool with statutory claim rules and other claimants.
HYRE analysis. That combination — long-tail obligations, a thin bond, and a counterparty whose continued existence is nobody’s job to guarantee — is why the license register is worth reading before signing rather than after.
It is also why the honest form of this page is a base rate rather than a warning. A base rate tells you how often to expect the question to arise. It does not tell you anything about the firm in front of you.
The base rate, stated carefully: among licenses that recently did repeat ADU work in these five jurisdictions, about 76% were standing when we looked and about 24% were not, for reasons that run from retirement to revocation and are not separable into “fine” and “not fine” from the status field alone.
Where the licenses stood on the harvest date
The board’s own status categories, with the board’s own words. We quote the status language verbatim rather than paraphrasing it, because the paraphrases in circulation are usually harsher than the register.
| Board status | Licenses | Share of frame | What the board’s own record says |
|---|---|---|---|
| Current and active | 738 | 76.5% | “This license is current and active. All information below should be reviewed.” |
| Expired | 86 | 8.9% | “This license is expired and not able to contract at this time.” A license expires if it is not renewed. It is the most ordinary way for a license to stop being active. |
| Revoked | 52 | 5.4% | “This license is revoked and not able to contract at this time.” This one is a disciplinary outcome. We report it as a count and we name nobody; what the board actually publishes about it is set out on the enforcement page. |
| Suspended | 44 | 4.6% | The board publishes a reason. In this frame the reasons are overwhelmingly administrative — a bond not on file, a workers’ compensation certificate not yet processed — and several of the board’s own suspension notices say the suspension “will be lifted retroactively” once the paperwork clears. |
| Canceled | 28 | 2.9% | “This license is canceled and not able to contract.” Frequently at the licensee’s own request: “LICENSE CANCELED PER REQUEST” appears 1 times in the entries we read. |
| Inactive | 16 | 1.7% | “This license is inactive and not able to contract at this time.” An inactive license is a license a holder has chosen to park. It can be reactivated. |
| Total | 965 | 100% | One license in the frame returned no readable status and is counted as unknown in the source file. |
CSLB Check a License, 2026-08-29 to 2026-08-30. Frame: distinct licenses held by contractors named on ADU permits at two or more distinct addresses in Los Angeles, San Francisco, Sacramento, San José or unincorporated Marin, holding B or B02. Licenses are counted once even where the firm appears in more than one jurisdiction.
The live re-check failed and we are saying so. On 2026-09-05 we attempted to re-read individual license detail pages to confirm these statuses were still current.
The board’s web application firewall rejected the request; the search form loaded but the detail pages did not. Every status on this page is therefore the 2026-08-29 to 2026-08-30 harvest.
For any specific firm, the board’s own service is the authority and it is free to use.
Does an older license mean a safer bet?
The intuitive answer is yes: a license that has been renewed for twenty-five years has survived twenty-five years of whatever kills contractors. The register does not really support it.
Licenses first issued before 2000 show 21.5% not current and active. The 2000–2009 cohort shows 17.1% — the lowest in the frame. The 2010–2014 cohort shows 25.3%, and the 2015–2019 cohort, which is both the largest in the frame and the one that maps onto the arrival of California’s modern ADU statutes, shows 28.8%.
HYRE analysis. The spread from best to worst cohort with a usable sample size is about 11.6% — real, but small next to the 23.5% base rate. License vintage is a weak predictor here.
That is worth saying because “how long have you been licensed?” is one of the two or three questions every hiring guide tells homeowners to ask, and on this evidence the answer discriminates much less than the question implies.
One caution about the newest cohorts. The 2020–2022 and 2023–2026 groups hold 60 and 18 licenses. Those are small, their shares move by whole percentage points on a handful of records, and they are drawn pale in the chart for that reason. Do not read a trend into them.
And a mechanical caveat. License age is time since first issue, not time doing ADU work — and a firm that reorganized from a sole ownership into a corporation appears in the register as a young license held by an old business. With 138 reissue entries in the frame, that is not a rare case.
The cohort chart as a table
Every bar above, with the components, so the chart is reproducible from this page.
| License first issued | Licenses | Current and active | Expired | Revoked | Suspended | Canceled | Inactive | Not current and active |
|---|---|---|---|---|---|---|---|---|
| before 2000 | 163 | 128 (78.5%) | 12 | 9 | 6 | 1 | 7 | 21.5% |
| 2000-2009 | 245 | 203 (82.9%) | 11 | 12 | 7 | 6 | 6 | 17.1% |
| 2010-2014 | 186 | 139 (74.7%) | 20 | 7 | 11 | 8 | 1 | 25.3% |
| 2015-2019 | 292 | 208 (71.2%) | 36 | 19 | 15 | 12 | 2 | 28.8% |
| 2020-2022 | 60 | 46 (76.7%) | 6 | 4 | 3 | 1 | 0 | 23.3% |
| 2023-2026 | 18 | 14 (77.8%) | 1 | 1 | 2 | 0 | 0 | 22.2% |
| Whole frame | 965 | 738 (76.5%) | 86 | 52 | 44 | 28 | 16 | 23.5% |
CSLB Check a License, harvested 2026-08-29 to 2026-08-30. Cohorts with fewer than 70 licenses are statistically unstable and are marked pale in the chart above.
Still permitting, or gone quiet?
The register status crossed against whether the firm’s most recent ADU permit in our extracts falls in 2024 or later. This is the closest thing to a forward-looking signal the data contains, and it is a weak one.
| Board status | Last ADU permit 2024 or later | Last ADU permit before 2024 | What it suggests |
|---|---|---|---|
| Current and active | 185 | 553 | The large majority of currently active licenses last appear in our extracts before 2024 — which is mostly an artefact of the Los Angeles feed, whose contractor columns end in May 2023, not evidence that those firms stopped. |
| Expired | 4 | 82 | Expiry concentrates overwhelmingly among firms whose last permit here predates 2024: 95% of expired licenses. Consistent with a license lapsing after a firm stops working, which is the ordinary sequence. |
| Suspended | 11 | 33 | Suspension is the one status that appears with any regularity alongside recent permitting. That fits the administrative nature of most suspensions: a bond or a certificate lapses while the firm is still trading. |
| Revoked | 2 | 50 | Almost entirely among firms whose last permit here predates 2024. We draw no conclusion about sequence from that; the extract windows differ by city and we cannot separate the two effects. |
| Canceled / inactive | 0 | 44 | Every canceled and inactive license in the frame last appears before 2024. Again, the extract windows do much of this work. |
HYRE calculation on the harvested register cross-tabulated against last-permit dates in the desk’s five municipal ADU extracts, 2026-09-05.
The confound is large and we will not paper over it. The Los Angeles legacy extract — which supplies most of the frame — carries contractor names only to 19 May 2023, because the newer LADBS feeds dropped every contractor column.
So “last permit before 2024” is, for a large share of these licenses, a statement about the dataset rather than about the firm.
This table is published because the pattern in the expired and suspended rows survives that confound in a way worth showing, not because it is clean.
What a homeowner can actually do with this
The base rate is context. These are the actions it supports. None of them requires our data, and all of them use the board’s record rather than ours.
- 1 Check the license yourself, on the day you sign
Not our snapshot — the board’s own Check a License service, free, at the moment of signing.
Confirm the license number, the exact business name, the classification, the status, the bond and the workers’ compensation position.
A status from a month ago is not a status today, which is why our own page carries a harvest date in every table.
- 2 Match the entity on the contract to the entity on the license
“LICENSE REISSUED TO ANOTHER ENTITY” appears 138 times in this frame — firms restructure often. The license protects you only in respect of the entity that holds it. If the contract is signed by a different company than the one on the license record, that is worth resolving before work starts, not after.
- 3 Read the bond for what it is
Of the licenses in this frame that publish a bond amount, 779 carry $25,000 and 61 carry $15,000. That is a licensing requirement, not a warranty fund and not project insurance, and it does not scale with the size of your job. Understanding its limits is more useful than being reassured by its existence.
- 4 Check the workers’ compensation position specifically
In this frame 646 licenses show a workers’ compensation policy on the board’s record and 312 show an exemption. An exemption means the licensee has certified it has no employees. If a crew turns up, that certification and your reality have diverged, and the exposure is yours as well as theirs.
- 5 Ask about warranty mechanics, not about longevity
Because license age turned out to be a weak signal, the more useful questions are structural: who honours the workmanship warranty if the entity changes, is there a manufacturer warranty that survives independently, is there a retention, and what happens to it. These are contract questions and the answers should be in writing.
- 6 And take the base rate as context, not as fear
About 76% of the licenses that recently did repeat ADU work in these five cities were standing when we looked. That is the ordinary condition of a construction market with a lot of small firms in it. It is a reason to check, not a reason to assume.
Method, and what we refused to compute
How the frame was built
From the desk’s five municipal ADU-permit harvests, we took every contractor named as contractor of record on ADU permits at two or more distinct site addresses within a single jurisdiction, holding a B or B02 classification.
Owner-builder permits are excluded outright under Business and Professions Code § 7044. Each resulting license number was then read on the board’s Check a License service.
That produced 965 distinct licenses: 636 from Los Angeles, 204 from San Francisco, 114 from Sacramento, 60 from San José and 31 from unincorporated Marin. Licenses are counted once even where the firm appears in more than one jurisdiction; on this frame only one license appears in more than one.
San Diego was harvested and is deliberately excluded, for the same reason it is excluded from our contractor index: its extract could not be reconciled to the same standard as the other five, and a jurisdiction we cannot stand behind does not get folded in quietly to make a number bigger.
How status and age were read
Status is the board’s own category, taken from the status text on the license detail page and normalised into the six categories the board uses. Where a license carries more than one suspension reason, every reason is counted, which is why the reason counts on the enforcement page exceed the number of suspended licenses.
License age is the difference between the issue date on the record and the harvest date, in years. Median 14.8, mean 17, quartiles 9.2 and 21.7, n = 964.
Reissue dates are recorded separately by the board and we did not substitute them for issue dates, which means a reorganized firm reads as a younger license than it is.
What we refused to compute
A survival curve. We hold the register at one date. A survival function needs entries and exits observed through time, and inventing one from a single snapshot would be a statistical error dressed up as a finding.
A failure rate. The status field does not distinguish a business that failed from one that retired, sold, restructured or simply did not renew. Calling 23.5% a failure rate would be wrong and would also be unfair to a large number of firms that did nothing but stop.
A list of names. There is no company-level output from this study and there will not be. The public interest in a base rate is real; the public interest in a HyreADU list of firms whose licenses lapsed is not, and the risk of harm to a firm mischaracterised by a status field is.
A California number. Five jurisdictions, a two-site floor and a B-class filter. Nothing here describes California contractors as a population.
Terms, used precisely
- Current and active
- The board’s own status: “This license is current and active. All information below should be reviewed.” Note the second sentence. The board itself does not treat the status line as the end of the inquiry.
- Expired
- A license that was not renewed by its expiry date. Ordinary, common, reversible, and not a disciplinary outcome.
- Canceled
- A license that has been ended — often at the licensee’s own request, sometimes on dissolution of the entity, sometimes on the death of the contractor. Not a disciplinary outcome either.
- Suspended
- A license the board has stopped from contracting for a stated reason, which the board publishes. In this frame those reasons are overwhelmingly administrative. Several suspension notices state that the suspension “will be lifted retroactively” once the paperwork is processed.
- Revoked
- A disciplinary outcome. The board’s language is “This license is revoked and not able to contract at this time.” We publish the count and nothing else; see the enforcement page for what the register does and does not disclose.
- License age
- Years between the issue date on the board’s record and our harvest date. Not years in business, and not years doing ADU work — a reorganized firm carries a young license.
- Contractor’s bond
- A licensing requirement. In this frame it is either $25,000 or $15,000. It is not a warranty, not project insurance, and it does not scale with the value of your contract.
Questions
What share of ADU builders go out of business?
Is an older, longer-established builder a safer bet?
Are bigger ADU builders more durable?
How do I check whether my builder is still licensed?
My builder’s license shows as suspended. Is that serious?
Does the contractor’s bond protect my deposit?
Why not publish the list of firms whose licenses lapsed?
Are these figures current?
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 CSLB Check a License records harvested 2026-08-29 to 2026-08-30; cohort computed 2026-09-05. A live re-check on 2026-09-05 was rejected by the board’s web application firewall, so no status on this page is a 5 September 2026 census.. 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
- California Contractors State License Board — Check a License , The primary source for every status, issue date, bond and workers’ compensation figure on this page. 965 distinct license records read on 2026-08-29 to 2026-08-30 from the license detail pages. A live re-check on 2026-09-05 was rejected by the board’s web application firewall: the search form at CheckLicense.aspx loaded, the LicenseDetail.aspx pages did not. Statuses are therefore the August harvest and not a September census. Retrieved 2026-09-05.
- California Business and Professions Code § 7044 — the owner-builder exemption , The provision under which a homeowner may permit their own work without a contractor’s license. Owner-builder permits are excluded from this frame entirely, which is why no share on this page describes the whole ADU permit population. Retrieved 2026-09-05.
- City of Los Angeles Department of Building and Safety — legacy building-permit extract (Socrata resource xnhu-aczu) , The source of the Los Angeles contractor-of-record names and license numbers that seed the largest part of this frame. The only published LADBS shape carrying contractor columns; its contractor evidence ends 19 May 2023, which is the confound named in the recent-activity table. Retrieved 2026-09-05.
- San Francisco Department of Building Inspection — building permits (data.sfgov.org resource i98e-djp9) , The only Californian ADU feed this desk has located that publishes the contractor’s CSLB license number on the permit, which makes the license match a lookup rather than a name match. Joined to the Building Permits Contacts resource on permit number. Retrieved 2026-09-05.
- HyreADU — five-jurisdiction ADU permit contractor index , The named-contractor index this frame is drawn from, with the per-jurisdiction row statistics, the owner-builder exclusions and the matching rules. Published in full, with the underlying CSV. Retrieved 2026-09-05.
Check the license on the day you sign
Our snapshot has a date on it and the board’s record does not need one. The bid-comparison tool sets out the license, bond, insurance and warranty questions to resolve before money moves — and it will never tell you a contractor is good.
This page names no company and publishes no company-level record. Every figure is an aggregate of the Contractors State License Board’s public register as read on 29–30 August 2026; the board’s own Check a License service is the authoritative and current source for any individual license, and it is free to use.
A license status is not a grade, not a verdict on workmanship, and not evidence about any particular job. A license that is not current and active today may have been current and active on every day a firm worked.
Non-active statuses include retirement, sale, reorganization into a new entity, non-renewal and death, and the register does not distinguish those from a business failure — so nothing here is a failure rate.
This is a snapshot of a register on one date and is not a survival study. The frame is five California jurisdictions and a two-site floor; it is not a sample of California contractors and no share here generalises to that population.
HyreADU does not design, permit or build accessory dwelling units, takes no payment for placement or a favorable mention, and offers no legal or financial advice.