October 6, 2026
A building permit is not a start date, and in Los Angeles it is not a finish date either. The City records the day a permit is issued and the day it signs off a certificate of occupancy, which makes the gap between them measurable for every new house built in the city since 2020.
We pulled all 8,102 new single-family house permits and 9,545 ADU permits issued in the City of Los Angeles from January 2020 to October 2026, and measured how long each one took to reach a certificate of occupancy. The short answer, for the 2020–2022 permits that are old enough to judge: the median new house took 16.1 months, but the middle half ran anywhere from 11.8 to 27.6 months, and one house in ten took more than 38.8 months. The spread matters far more than the average.
This report publishes the full dataset. Figures below are open to interpretation and we draw no causal conclusions from them — the permit record shows what happened, not why.
The Dataset
- Source: City of Los Angeles open data, dataset
pi9x-tg5x— Building and Safety permits issued from 2020 to present. Public, updated daily, extracted 2026-10-04. - Universe: every
Bldg-Newpermit with the use Dwelling – Single Family (8,102 permits) or Accessory Dwelling Unit (9,545 permits), issued citywide between January 2020 and October 2026. - What is being measured: calendar months from the permit issue date to the certificate of occupancy date on the same permit. That covers construction and sign-off only. Design, plan check, entitlement and any appeals happen before issue and are not in these numbers.
- What a certificate of occupancy is: the City's confirmation that the building may be legally occupied. It is not a move-in date, and it is not the day the last trade left the site.
- The dataset begins in 2020, so no permit issued before January 2020 is included, and nothing here describes build times in the 2010s.
Finding 1: The Median Is 16 Months — and the Median Hides Almost Everything
Across the 2,946 new houses permitted in 2020–2022 that have since reached a certificate of occupancy, the median time from permit issue to sign-off was 16.1 months. The quartiles tell a much less comfortable story: a quarter were done in under 11.8 months, a quarter took more than 27.6 months, and the slowest tenth passed 38.8 months. The longest in the set ran 79.3 months — nearly six and a half years.
Put differently: the gap between a fast build and a slow one in this dataset is more than two years, on projects that all began as a single-family house permit in the same city.
Finding 2: At Best, One House in Four Finishes Within a Year
Measuring only the houses that have finished would flatter every recent year, because a house permitted in 2025 has not had time to fail to finish. So instead we take every permit issued in a given year and ask what share had reached a certificate of occupancy within 12, 24, 36 and 48 months — the whole cohort as the denominator, including the ones that never got there.
For the 2021 cohort (1,107 permits), the curve fills in slowly:
Four years after the permit was issued, 15.4% of that cohort still had no certificate of occupancy. Some of those houses were finished and recorded another way, some stalled, some were never built. The permit record does not say which.
Finding 3: The Two-Year Completion Rate Has Been Sliding
Comparing the same 24-month horizon across cohorts removes the survivorship problem entirely — every cohort below has had a full two years to run. On that like-for-like basis the share of new houses finishing within two years fell from 61.4% for permits issued in 2021 to 50.8% for permits issued in 2023.
Share of each issue-year cohort of new single-family house permits with a certificate of occupancy, by months elapsed. The 2022 line stops at 36 months because the 48-month mark has not yet passed for every permit in that cohort.
Finding 4: Where You Build Moves the Timeline More Than Anything Else We Measured
Across the 22 community plan areas with at least 40 completed houses, the median build time ranges from 9.4 months in Mission Hills - Panorama City - North Hills to 36.4 months in Bel Air - Beverly Crest — a spread of roughly 3.9x between the slowest and fastest parts of the same city.
The hillside and high-value areas sit at the top of that list; the flatter, more subdivision-driven parts of the Valley and the Harbor sit at the bottom. Those two groups are not building the same product under the same site conditions, which is part of why the citywide median is a weak guide to any individual project.
Finding 5: The Largest Houses Take Two and a Half Times as Long — and an ADU Takes as Long as a House
Sorted by the square footage declared on the permit, the relationship is not a straight line. Houses in the 4,000–6,000 sq ft band were the quickest at a 14-month median, while houses above 10,000 sq ft ran 37.2 months. Houses under 2,000 sq ft were slower than the mid-size bands too.
The ADU comparison is the one most likely to surprise. Across the same 2020–2022 cohorts, the median ADU took 16.1 months from permit to certificate of occupancy — statistically indistinguishable from the 16.1 months a full new house took. ADUs did start faster at the quick end (10.9 months for the fastest quarter against 11.8 for houses) and clustered tighter at the slow end (24.1 months against 27.6), but the typical ADU was not a materially shorter project.
The Numbers
Share of each issue-year cohort reaching a certificate of occupancy within each horizon. A blank cell means the horizon has not yet fully elapsed for every permit in that cohort, so no honest figure can be given.
New single-family houses
| Issue year | Permits | 12 mo | 24 mo | 36 mo | 48 mo | No CofO to date |
|---|---|---|---|---|---|---|
| 2020 | 1,033 | 24.1% | 60.3% | 73.7% | 82.0% | 117 (11%) |
| 2021 | 1,107 | 25.1% | 61.4% | 78.2% | 84.6% | 116 (10%) |
| 2022 | 1,299 | 21.3% | 54.1% | 70.0% | — | 260 (20%) |
| 2023 | 1,069 | 16.6% | 50.8% | — | — | 269 (25%) |
| 2024 | 911 | 22.4% | — | — | — | 392 (43%) |
| 2025 | 1,416 | — | — | — | — | 1,083 (76%) |
| 2026 | 1,267 | — | — | — | — | 1,261 (100%) |
Accessory dwelling units
| Issue year | Permits | 12 mo | 24 mo | 36 mo | 48 mo | No CofO to date |
|---|---|---|---|---|---|---|
| 2020 | 587 | 33.0% | 65.6% | 77.9% | 81.6% | 81 (14%) |
| 2021 | 994 | 23.7% | 63.8% | 74.4% | 79.7% | 178 (18%) |
| 2022 | 1,626 | 22.7% | 57.1% | 70.6% | — | 345 (21%) |
| 2023 | 1,489 | 23.3% | 58.3% | — | — | 381 (26%) |
| 2024 | 1,616 | 27.4% | — | — | — | 552 (34%) |
| 2025 | 1,791 | — | — | — | — | 1,037 (58%) |
| 2026 | 1,442 | — | — | — | — | 1,415 (98%) |
Possible Readings
The permit record measures timing. It does not record why any individual project took as long as it did, so the explanations below compete rather than resolve, and we leave them open.
- The slide in two-year completions could be supply-side. Labour availability, materials lead times and inspection scheduling all plausibly lengthened over this period. The data cannot separate them.
- It could equally be a change in what is being built. If the mix shifted toward larger or more constrained hillside projects, the aggregate would slow even if no individual project got slower.
- The geographic spread may be site conditions rather than geography. Hillside grading, retaining structures, access and fire-zone requirements all concentrate in the slower areas.
- Or it may be the product. The fastest areas include subdivision work built repeatedly to one set of plans — roughly 18.4% of completed houses sit in groups of five or more sharing a single sign-off date in one area. Excluding the single largest such area moves the citywide median from 16.1 to 18.8 months.
- The small-house result resists a simple reading. Houses under 2,000 sq ft were slower than mid-size ones, which is consistent with owner-driven or self-financed projects, with infill sites, or with square footage being recorded unevenly on smaller permits.
- The unfinished share is genuinely ambiguous. A permit with no certificate of occupancy may be stalled, abandoned, superseded by a later permit, finished but recorded differently, or still legitimately under construction.
Opportunity Spotlight
- A 12-month build promise is an outlier claim, not a baseline. Fewer than a quarter of new houses permitted in any observable cohort reached sign-off inside a year. Any schedule built around that figure is planning for the best quartile of outcomes.
- Budget the carry, not the construction. The difference between the 11.8-month quartile and the 38.8-month decile is more than two years of financing, insurance, storage and alternative housing on a project whose hard costs were quoted once.
- Area matters at the feasibility stage. A buyer comparing a hillside lot against a flat one is, on these numbers, also comparing very different median timelines — and the time gap shows up in carrying cost long before it shows up in the build.
- An ADU is not automatically the quick option. It may still be the right one on cost, planning or yield grounds, but the permit record does not support choosing it for speed alone.
Method
- Every
Bldg-Newpermit with use Dwelling – Single Family or Accessory Dwelling Unit was retrieved from datasetpi9x-tg5xon 2026-10-04. The broader "1 or 2 Family Dwelling" sub-type was deliberately not used: it also contains garages, patio covers, carports and sheds. - Duration is the number of days between
issue_dateandcofo_dateon the same permit, divided by 30.44. Rows where the certificate predates the permit were excluded; there were none in this extract. - Survivorship was the main hazard and is handled two ways. Completion is reported as a fixed-horizon share of an entire issue-year cohort, not as an average over finished projects. A horizon is reported only when every permit in that cohort has had the full period to run against the extract date; otherwise it is left blank.
- Median durations are quoted only for the 2020–2022 cohorts, which are mature enough that most of their permits have resolved. Quoting a median for 2025 would measure nothing but the fastest builds.
- Completion shares are a floor. Roughly 4% of 2020–2022 permits carry a finished-looking status with no certificate date attached, so they count here as not complete. The true completion rate is slightly higher than every figure above.
- Community plan area medians are published only where at least 40 completed houses support them, which yields 22 of the City's areas.
- Square footage and valuation are stored as text in the source and were cast to numbers; both are self-declared on the permit application and are uneven in quality.
Download the Data
The full dataset behind this report is published openly for reuse. Attribution to Blackbriar is welcome but not required; the underlying records are the City of Los Angeles'.
- cohort-completion.csv — completion share at each horizon, by issue year, for houses and ADUs
- duration-by-community-plan-area.csv — median, quartile and 90th-percentile build times for 22 community plan areas
- build-timeline.json — the complete structured dataset, including size bands, source metadata and caveats
How Blackbriar Uses This
We build custom homes in Los Angeles, so these are our own numbers as much as anyone's. What the record changes about how we work with clients is mostly at the front end: a realistic schedule is set against the distribution rather than the median, the carrying cost of the slow tail is priced before contracts are signed, and the site's own conditions — hillside, access, fire zone — are treated as schedule inputs rather than construction details. If you are weighing a site or a schedule, our process and services pages set out how we approach both, and you can talk to us directly.
FAQ
How long does it take to build a house in Los Angeles?
Across 2,946 new single-family houses permitted in the City of Los Angeles between 2020 and 2022, the median time from permit issue to certificate of occupancy was 16.1 months. The middle half took between 11.8 and 27.6 months, and the slowest ten per cent took more than 38.8 months. These figures cover construction and sign-off only — design, plan check and entitlement all happen before the permit is issued.
What share of Los Angeles houses are finished within a year of permitting?
Between 16.6% and 25.1%, depending on the year the permit was issued. For the 2021 cohort it was 25.1%. A one-year build is an outlier outcome rather than a typical one.
Is building an ADU faster than building a house in Los Angeles?
Not on the permit record. The median ADU permitted in 2020–2022 took 16.1 months from issue to certificate of occupancy, against 16.1 months for a new single-family house. ADUs finished a little sooner at the fast end and clustered tighter at the slow end, but the typical timeline was comparable.
Which parts of Los Angeles have the longest build times?
Of the 22 community plan areas with enough completed houses to measure, Bel Air - Beverly Crest had the longest median at 36.4 months, followed by Northeast Los Angeles at 32.4 months. The shortest was Mission Hills - Panorama City - North Hills at 9.4 months. Hillside and high-value areas sit at the slow end of the range.
Does a certificate of occupancy mean the house is finished?
It means the City has confirmed the building can be legally occupied. It is not a move-in date and not necessarily the day construction ended. Some finished houses are also recorded under other permit statuses without a certificate date, which is why the completion shares in this report are a floor rather than an exact count.
Where does this data come from?
The City of Los Angeles open data portal, dataset pi9x-tg5x, covering building permits issued from 2020 to present. It was extracted on 2026-10-04 and covers 8,102 new house permits and 9,545 ADU permits. The processed dataset is published for download with this report.
Recommended
- 2026 Los Angeles Residential Building Permit Report — how many houses are being permitted, and where
- 2026 Los Angeles Hillside Construction Report — the site conditions behind the slowest areas in this report
- 2026 Los Angeles Lot Due Diligence Report — what to check before a site becomes a schedule problem