HyreADU

Statistics

ADU zoning statistics

37 of 62 figures are HyreADU calculations. In California, zoning no longer decides whether an ADU is allowed — so the zoning statistics worth publishing are about the envelope the state guarantees, and where the units actually land.

Updated September 2026 · Data as of Government Code Chapter 13 retrieved from leginfo 2026-09-05, §§ 66321 and 66323 re-verified verbatim 2026-09-07; LADBS resource pi9x-tg5x rows refreshed 2026-08-30; HCD RHNA Progress Report and Annual Progress Report Table A2 retrieved 2026-09-05

Written by HyreADU Research Desk Primary-source research and data analysis

Audited by HyreADU Research Desk Statutory citation and provenance audit

37 of 62 figures are HyreADU calculations 37 HyreADU calculation · 25 Agency published. Below one-third we publish the study, not a digest.
58.1% of Los Angeles ADU permits are in a single-family residential zone HyreADU calculation: 22,839 of 39,279 permits, counting only the ten largest zone districts. Against 9.3% in the multi-family zones inside that same ten.
231 of 1,142 census tracts carry half of all ADU permits HyreADU calculation. Gini 0.4731 across tracts; the busiest quartile carries 57.3%. Uniform rules, extremely non-uniform take-up.

How to use this page

In California, the local zoning map no longer answers the question “can I build an accessory dwelling unit here?” Government Code section 66319 makes an ADU an accessory use not counted toward density; section 66318 excludes ADUs from local growth limits; section 66312 binds charter cities; sections 66320 and 66323 require ministerial approval whatever the local ordinance says; and section 66316 makes a non-compliant ordinance null and void.

Each provision is quoted below. What zoning still decides is the envelope — and even there the state sets a floor a city cannot go below: at least 850 square feet of interior livable space, or 1,000 with more than one bedroom; no requirement that prevents an 800 square foot unit at four-foot side and rear setbacks; 16 feet of height detached, 18 near transit, 25 attached; setbacks of no more than four feet.

So the useful zoning statistic is not what is permitted. It is where the units land. In our extract of the City of Los Angeles permit file, 11,730 of 39,279 ADU-adding permits — 29.86% — are in a single zone district, R1-1, and at least 58.15% of the frame sits in a single-family residential zone against 9.35% in the multi-family zones inside the same top ten.

On this record the ADU statute is, in outcome terms, a single-family-zone instrument. Take-up is far less uniform than the rules are. The same permits spread across 1,142 census tracts, but 231 tracts carry half of them.

Statewide, the accessory route is now doing a large share of the work of the housing element system: ADU permits are 24.9% of every unit permitted against California’s sixth-cycle regional housing needs allocation so far.

37 of 62 figures on this page are HyreADU calculations (37 hyreadu calculation, 25 agency published). Not legal advice.

Read this before you quote anything here

  • Every zone and tract figure is the City of Los Angeles

    The zone-district composition, the tract concentration and the area splits all come from one city’s permit file.

    Los Angeles is the largest ADU market in the United States by permit volume and the only jurisdiction this desk has found publishing a departmental ADU flag on a complete extract with a zone field.

    It is still one zoning code. 58.1% is a Los Angeles figure and not a California one.

  • The single-family / multi-family classification is ours, and it covers only the top ten zones

    The zone strings — R1-1, RS-1, R2-1 and the rest — are the City’s own field.

    Assigning them to “single-family” or “multi-family” is a HyreADU judgment, made from the Los Angeles zoning code’s own descriptions of each district, and we publish which zone we put in which bucket so the call can be argued with.

    The ten largest districts cover 67.5% of the frame; the remaining 32.5% is not classified on this page and is shown as its own segment rather than being assumed to fall one way.

  • A permit count is not a rate, and this page publishes no rate

    To say a tract or a zone is “more receptive” to ADUs you would need a denominator — eligible parcels, single-family households, or lot area — and we do not hold a parcel-level denominator for Los Angeles.

    Everything here is a share of permits, not a rate per eligible lot. A busy tract may simply be a large tract with many houses in it.

  • The state floor is a floor, so a more permissive city is complying

    Section 66325(b) preserves local authority “to adopt less restrictive requirements for the creation of an accessory dwelling unit”.

    A city that allows 1,200 square feet where the state floor is 850, or requires no parking at all, is doing exactly what the scheme contemplates.

    Nothing in the envelope table is a requirement a city must impose.

  • We name no jurisdiction as non-compliant

    Whether a particular clause in a particular ordinance is preempted is a legal conclusion that turns on the whole ordinance, its adoption date and its submission history with HCD.

    The authoritative record is HCD’s own written findings under section 66326. This page describes the mechanism and describes no city as having a non-compliant clause. The ordinance tracker explains why, and what it would take to say otherwise.

Read the provenance, not just the number

Two kinds of fact, kept apart on every row.

Agency published — the statutory envelope and the preemption machinery, quoted from the Government Code as retrieved on 2026-09-05, with sections 66321 and 66323 re-verified verbatim on 2026-09-07; and the jurisdiction and allocation counts published by HCD.

HyreADU calculation — the zone composition, the tract concentration, the area shares and every share of permitted units. Computed from the City of Los Angeles permit extract and from HCD’s own downloadable RHNA and Annual Progress Report files. These are not figures published by the City or by HCD.

A citation warning specific to this subject. The California ADU statute has been recodified twice. SB 477 (Stats. 2024, Ch. 7) repealed Government Code section 65852.2 and created Chapter 13, sections 66310 to 66342, effective 25 March 2024.

SB 543 (Stats. 2025, Ch. 520) then renumbered sections within that chapter with effect from 1 January 2026 — the fee section moved from § 66324 to § 66311.5, and the unpermitted-unit section from § 66332 to § 66311.7.

We re-verified the Chapter 13 section list on 2026-09-07: §§ 66324, 66327 and 66332 no longer appear in it. Any zoning guidance citing § 65852.2, or any of those three numbers, is citing a section that has been repealed or renumbered.

The figures most worth knowing

29.9% of Los Angeles ADU permits are in one zone district, R1-1 HyreADU calculation · 11,730 of 39,279
6.2× as many ADU permits in single-family zones as in multi-family zones, inside the top ten districts HyreADU calculation · 22,839 against 3,672
850 sq ft the smallest maximum size a California city may impose Agency published · § 66321(b)(2)
4 categories a city must approve ministerially whatever its zoning says Agency published · § 66323(a)(1)–(4)
0.47 Gini coefficient of ADU permits across Los Angeles census tracts HyreADU calculation · 1,142 tracts
24.9% of all units permitted against California’s sixth-cycle RHNA are ADUs HyreADU calculation · from HCD’s own RHNA file

A share of permits is not a rate per eligible lot. The where ADUs are built study carries the geography in full.

The provisions that took the question out of zoning

Before any envelope number is useful, this is the layer that matters: six provisions that between them stop a zoning map, a density cap, a growth-control ordinance, a charter, a missing ordinance or a non-compliant one from answering the question. Every value here is agency published — the Legislature’s, not ours.

ProvisionWhat it removes from the zoning systemClass
§ 66319Density. An ADU is deemed an accessory use, and is not counted toward the density permitted on the lot. A lot at its density cap is still a lot that can take an ADU.Agency published
§ 66318Growth management. ADUs are excluded from the residential growth limits a local agency may otherwise impose, and a local agency may amend its zoning to provide for them.Agency published
§ 66312The charter-city argument. The chapter applies to a charter city notwithstanding Government Code § 65803.Agency published
§ 66323(a)(1)–(4)Discretion over four specific unit types. A city must ministerially approve each of them, whatever its ordinance provides.Agency published
§ 66320The gap where no ordinance exists. A local agency that has adopted no ADU ordinance must still approve or disapprove ministerially under § 66317.Agency published
§ 66316The survival of a non-compliant clause. A non-compliant ADU ordinance “shall be null and void” and the agency applies the state standards until it adopts a compliant one. The default is not that the clause stands until challenged.Agency published
§ 66326The consequence of ignoring HCD. A missed 60-day submission or 30-day response deadline voids the ordinance automatically — added by SB 9 (Arreguín, Stats. 2025, Ch. 510), effective 1 January 2026.Agency published
§ 66325Conflicting local text, in both directions. (a) the article supersedes a conflicting local ordinance; (b) a local agency may still adopt less restrictive requirements.Agency published

California Government Code Chapter 13, retrieved 2026-09-05 and re-verified against the chapter section list 2026-09-07.

Note the bill-number collision, because it causes real confusion. The SB 9 that amended § 66326 is SB 9 (Arreguín, Stats. 2025, Ch. 510), on ADU ordinances. It is not SB 9 (Atkins, Stats. 2021, Ch. 162), the urban lot-split statute.

Two different laws, both routinely called “SB 9”, both bearing on a single-family lot. The SB 9 study covers the 2021 one, including the important point that a parcel using SB 9 lot-split powers loses the guaranteed ADU and JADU right.

The envelope zoning still controls — and the floor under it

What a California local agency must permit, whatever its own code says. These are minimums a city may not go below, not maximums it must impose.

Three different sections carry size numbers and they are not alternative statements of the same rule: § 66321(b)(2) sets the smallest maximum a city may impose, § 66321(b)(3) guarantees an 800 square foot unit at four-foot setbacks, and § 66314(d)(4)–(5) caps what a city may allow.

Detached ADU — standard16 ft
The baseline a local agency may not go below.
Detached — within ½ mile of a major transit stop18 ft
Plus up to two feet to align roof pitch with the primary dwelling.
Detached — on a lot with a multistory multifamily dwelling18 ft
The same figure by a different route.
Attached ADU25 ft
Or the local zoning height limit for the primary dwelling, whichever is lower.
FieldThe state floorSectionCurrencyClass
Smallest maximum size a city may impose850 sq ft interior livable space; 1,000 sq ft with more than one bedroom§ 66321(b)(2)Amended by Stats. 2025, Ch. 520, Sec. 5 (SB 543), eff. 1 Jan 2026Agency published
Minimum size a city may imposeNone that prohibits an efficiency unit§ 66321(b)(1)Same amendmentAgency published
The 800 sq ft / four-foot guaranteeNo requirement may prevent an ADU of at least 800 sq ft with four-foot side and rear yard setbacks§ 66321(b)(3)Same amendmentAgency published
Height — detached, standard16 ft§ 66321(b)(4)Same amendmentAgency published
Height — detached, within half a mile of a major transit stop, or on a lot with a multistory multifamily dwelling18 ft, plus up to 2 ft to align roof pitch with the primary dwelling§ 66321(b)(4)Same amendmentAgency published
Height — attached25 ft, or the local zoning height limit for the primary dwelling, whichever is lower§ 66321(b)(4)Same amendmentAgency published
Setbacks — new constructionNo more than 4 ft from side and rear lot lines§ 66314(d)(7)Amended by Stats. 2025, Ch. 67, Sec. 109 (AB 1170), eff. 1 Jan 2026Agency published
Detached unit size ceiling a city may set1,200 sq ft§ 66314(d)(5)Same amendmentAgency published
Attached unit size ceiling a city may setNot below 50 per cent of the existing primary dwelling§ 66314(d)(4)Same amendmentAgency published
Approval pathwayMinisterial, no hearing, no discretionary review§ 66317(a)(1)Amended by Stats. 2025, Ch. 520, Sec. 3 (SB 543), eff. 1 Jan 2026Agency published
Decision deadline60 days, then deemed approved§ 66317(a)(3)Same amendmentAgency published

Government Code §§ 66314 and 66321, retrieved 2026-09-05; § 66321(b) re-verified verbatim 2026-09-07, enactment line “Amended by Stats. 2025, Ch. 520, Sec. 5. (SB 543) Effective January 1, 2026.” Eleven agency-published values.

Height is the field where local ordinances diverge most on measurement rather than on number. To the ridge, to the mid-point of the roof, or to the top plate — sixteen feet measured three ways is three different buildings.

The ordinance tracker records the measurement basis as a separate coded field from the figure for exactly this reason.

The four categories a city must approve whatever the zone says

Section 66323 is the provision that makes the zoning map largely irrelevant to whether an ADU is allowed. A local agency must ministerially approve each of these, and subdivision (e) requires it to impose a minimum rental term longer than 30 days on them. Quoted from the section as re-verified on 2026-09-07.

1. § 66323(a)(1)

One accessory dwelling unit and one junior accessory dwelling unit per lot with a proposed or existing single-family dwelling, subject to the conditions in that paragraph, including an expansion of not more than 150 square feet.

2. § 66323(a)(2)

One detached, new-construction accessory dwelling unit that does not exceed four-foot side and rear yard setbacks, with an optional floor area limitation of not more than 800 square feet of livable space.

3. § 66323(a)(3)

Multiple accessory dwelling units within the portions of an existing multifamily structure not used as livable space — at least one, and up to 25 per cent of the existing multifamily dwelling units.

4. § 66323(a)(4)

Not more than eight detached accessory dwelling units on a lot with an existing multifamily dwelling, not exceeding the number of existing units.

The two multifamily paragraphs are the least used and the most structurally interesting. Subdivision (a)(3) forces a conversion route inside existing multifamily buildings — the boiler rooms, storage rooms and unused common space — and (a)(4) forces up to eight detached units on an existing multifamily lot.

Between them they make the accessory route available on land that has nothing to do with a single-family back garden.

On the Los Angeles permit record, that is not where most of the units are going: 9.3% of the frame is in the three multi-family zones inside the top ten districts, against 58.1% in single-family zones.

Whether that is a demand fact, an ownership fact or a financing fact, we have not measured, and we are not going to guess in a table.

Which zones the permits are actually in

The zone breakdown is the finding this digest exists for. The ten largest zone districts in the Los Angeles ADU permit frame, with the count and share for each. The zone strings are the City’s own field.

The classification into single-family and multi-family residential is ours, made from the Los Angeles zoning code’s description of each district, and it is published in the table so it can be argued with rather than assumed.

Zone districts of Los Angeles ADU permits, 2020–202629.9%R1-1 (single-family) — 11,73010.9%RS-1 (single-family) — 4,276R1-1-RIO (single-family) — 2,180R2-1 (multi-family) — 1,618RA-1 (single-family) — 1,599R1V2 (single-family) — 1,197R3-1 (multi-family) — 1,139RE11-1 (single-family) — 970RD1.5-1 (multi-family) — 915R1-1-CUGU (single-family) — 88732.5%All other zone districts (unclassified here) — 12,768HyreADU calculation from LADBS pi9x-tg5x, rows refreshed 2026-08-30. Zone strings are the City’s; the single-family / multi-familyclassification is HyreADU’s and covers only the ten largest districts. Every value is in the table below.
Composition of 39,279 City of Los Angeles ADU-adding permits by zone district. R1-1 alone is 29.9%. Single-family zones inside the top ten account for 58.1% of the frame; multi-family zones for 9.3%; everything outside the top ten is shown as one unclassified segment at 32.5%. Chart: HyreADU Research Desk from LADBS resource pi9x-tg5x, rows refreshed 2026-08-30. Every plotted value is in the table below.
Zone districtWhat it isPermitsShare of frameClassSource
R1-1One-Family, Height District 1 — the base single-family zone11,73029.86%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
RS-1Suburban — a lower-density single-family zone4,27610.89%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
R1-1-RIOOne-Family with a River Improvement Overlay2,1805.55%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
R2-1Two-Family1,6184.12%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
RA-1Suburban / agricultural — single-family1,5994.07%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
R1V2One-Family variation zone (V2 lot-size class)1,1973.05%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
R3-1Multiple Dwelling1,1392.90%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
RE11-1Residential Estate, 11,000 sq ft minimum lot — single-family9702.47%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
RD1.5-1Restricted Density Multiple Dwelling9152.33%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
R1-1-CUGUOne-Family with a Clean Up Green Up supplemental district8872.26%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Subtotal — single-family zones aboveR1-1, RS-1, R1-1-RIO, RA-1, R1V2, RE11-1, R1-1-CUGU22,83958.15%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Subtotal — multi-family zones aboveR2-1, R3-1, RD1.5-13,6729.35%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
All other zone districtsNot classified on this page12,76832.51%HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study

HyreADU calculation from LADBS resource pi9x-tg5x, 409,619 rows downloaded, rows refreshed 2026-08-30. The ten districts shown cover 67.49% of the frame. Ratio of single-family to multi-family permits inside the top ten: 6.2 to 1.

The reading, stated as analysis rather than as a measurement of intent. California’s ADU statute is written to apply on any residential lot, and §§ 66323(a)(3) and (a)(4) go out of their way to open multifamily land.

On this one city’s record, the units are overwhelmingly landing in the base single-family zone.

That is what a de facto upzoning of single-family land looks like from the permit counter — and it is the strongest available answer to the question of what the statute did to the zoning map, because it does not depend on anybody’s account of their own intentions.

Uniform rules, extremely non-uniform take-up

The state rules are identical across every parcel in the city, and the local ordinance is identical across every parcel in the city. The outcome is not. 231 of 1,142 census tracts carry half of all ADU permits, and 526 carry 80 per cent. The Gini coefficient across tracts is 0.4731.

ADU permits are far more concentrated than the zoning that allows themLorenz curve of accessory dwelling unit permits across 1,142 City of Los Angeles census tracts, tracts ordered from busiest to least busy. The busiest tenth of tracts carries 30.4% of permits and the busiest quarter carries 57.3%; 231 tracts account for half of all permits. Gini coefficient 0.4731.0%0%20%20%40%40%60%60%80%80%100%100%Even spread across tracts231 tracts (22.1%) carry half the permitsCumulative share of ADU permitsCensus tracts, busiest firstGini 0.4731 across 1,142 tracts. HyreADU calculation from LADBS pi9x-tg5x. All plotted values are in the table below.
Lorenz curve of ADU permits across 1,142 Los Angeles census tracts, tracts ordered busiest first. The dashed diagonal is what an even spread would look like. The busiest tenth of tracts carries 30.4% of permits; the busiest quarter carries 57.3%. Chart: HyreADU Research Desk from LADBS pi9x-tg5x. Curve drawn from the published cumulative shares; every labeled value is in the table below.
MeasureValueWhat it saysClassSource
Census tracts with at least one ADU permit1,142The permits are not confined to a handful of neighborhoods — the base is wide.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Median permits per tract26The typical tract has issued a couple of dozen ADU permits in six and a half years.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Permits in the busiest tract190More than 7 times the median tract.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Tracts carrying half the permits23120.2% of tracts, half the output.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Tracts carrying 80 per cent52646.1% of tracts.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share in the busiest decile of tracts30.4%Concentrated, but not a handful-of-blocks phenomenon.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share in the busiest quartile of tracts57.3%A quarter of tracts, well over half the permits.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Gini coefficient across tracts0.4731Substantial inequality of output across a city with one rule set.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share in the San Fernando Valley area planning commissions53.8%North and South Valley together, against five other area planning commissions.HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study

HyreADU calculation from LADBS pi9x-tg5x, 39,279 permits geocoded to a census tract. Concentration measures are of permits, not of a rate per eligible lot.

Do not read this as a map of where ADUs are welcome. A tract with many single-family houses on generous lots will produce more ADU permits than a tract of apartment blocks under identical rules, and a large tract will out-produce a small one.

Turning this into a receptiveness measure needs a parcel-level denominator we do not hold.

What the Gini does establish is that the uniformity of the rule has not produced uniformity of outcome, which is the honest and useful version of the claim.

What the accessory route is doing to the housing element system

The other zoning statistic worth having is what share of everything a jurisdiction permits is now arriving through the accessory route rather than through the zoning map’s own capacity.

Statewide, against California’s sixth-cycle regional housing needs allocation, 24.9% of all units permitted so far are ADUs. Across the ten focus jurisdictions the spread runs from 52.1% to 5.5%.

JurisdictionCycle years countedADU permitsAll units permittedADU share of units permittedClassSource
Long Beach2022–20252,5714,93152.1%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Unincorporated Los Angeles County2022–20253,96910,16439.1%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Los Angeles2022–202528,95177,29637.5%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Unincorporated San Diego County2022–20251,6176,17626.2%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
San Diego2022–20256,96536,53319.1%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Oakland2024–20254052,53516.0%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
San José2024–20251,0607,81913.6%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Sacramento2022–20251,28214,0249.1%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
San Francisco2024–20254016,0866.6%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Fresno2024–20251883,4155.5%HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study

HyreADU calculation from HCD’s sixth-cycle RHNA Progress Report file on data.ca.gov, retrieved 2026-09-05, HCD file last updated 2026-09-04.

Statewide: 477,627 units permitted against an allocation of 2,495,457 across 539 jurisdictions — 19.1% of the allocation, of which 24.9% are ADUs.

Cycle start dates differ by council of governments, so the years counted differ by jurisdiction and the shares are not directly comparable between rows with different windows.

Two cautions that matter more than the numbers. First, cycle windows differ: Long Beach and Los Angeles are counted over four years and Oakland, San Francisco, San José and Fresno over two, so a low share may be a short window as much as a low rate.

Second, a permit is not a completion and a completion is not affordability — the accessory route delivers overwhelmingly to the above-moderate income category, and the production against housing need study is where that argument belongs. This row is a zoning statistic, not a housing-need verdict.

Every figure on this page, with its class

The full ledger, so the 37-of-62 split can be checked rather than taken on trust. Nothing appears anywhere on this page that is not in this table.

StatisticFigureGeographyDateClassSource
Smallest maximum size a city may impose850 sq ft interior livable space; 1,000 sq ft with more than one bedroomCaliforniaIn force 2026Agency publishedGov. Code § 66321(b)(2), leginfo, 2026-09-05
Minimum size a city may imposeNone that prohibits an efficiency unitCaliforniaIn force 2026Agency publishedGov. Code § 66321(b)(1), leginfo, 2026-09-05
The 800 sq ft / four-foot guaranteeNo requirement may prevent an ADU of at least 800 sq ft with four-foot side and rear yard setbacksCaliforniaIn force 2026Agency publishedGov. Code § 66321(b)(3), leginfo, 2026-09-05
Height — detached, standard16 ftCaliforniaIn force 2026Agency publishedGov. Code § 66321(b)(4), leginfo, 2026-09-05
Height — detached, within half a mile of a major transit stop, or on a lot with a multistory multifamily dwelling18 ft, plus up to 2 ft to align roof pitch with the primary dwellingCaliforniaIn force 2026Agency publishedGov. Code § 66321(b)(4), leginfo, 2026-09-05
Height — attached25 ft, or the local zoning height limit for the primary dwelling, whichever is lowerCaliforniaIn force 2026Agency publishedGov. Code § 66321(b)(4), leginfo, 2026-09-05
Setbacks — new constructionNo more than 4 ft from side and rear lot linesCaliforniaIn force 2026Agency publishedGov. Code § 66314(d)(7), leginfo, 2026-09-05
Detached unit size ceiling a city may set1,200 sq ftCaliforniaIn force 2026Agency publishedGov. Code § 66314(d)(5), leginfo, 2026-09-05
Attached unit size ceiling a city may setNot below 50 per cent of the existing primary dwellingCaliforniaIn force 2026Agency publishedGov. Code § 66314(d)(4), leginfo, 2026-09-05
Approval pathwayMinisterial, no hearing, no discretionary reviewCaliforniaIn force 2026Agency publishedGov. Code § 66317(a)(1), leginfo, 2026-09-05
Decision deadline60 days, then deemed approvedCaliforniaIn force 2026Agency publishedGov. Code § 66317(a)(3), leginfo, 2026-09-05
Density treatment of an ADUAn accessory use; not counted toward the density permitted on the lotCaliforniaIn force 2026Agency publishedGov. Code § 66319, 2026-09-07
Treatment under a local growth-management limitADUs are excluded from residential growth limits a local agency may imposeCaliforniaIn force 2026Agency publishedGov. Code § 66318, 2026-09-07
Application to charter citiesThe chapter applies notwithstanding Gov. Code § 65803CaliforniaIn force 2026Agency publishedGov. Code § 66312, 2026-09-05
Effect of a non-compliant local ADU ordinanceNull and void; the agency applies the state standards until it adopts a compliant oneCaliforniaIn force 2026Agency publishedGov. Code § 66316, 2026-09-05
Effect where a local agency has adopted no ADU ordinance at allIt must still approve or disapprove ministerially under § 66317CaliforniaIn force 2026Agency publishedGov. Code § 66320, 2026-09-05
Consequence of missing the HCD ordinance-submission or response deadlineThe ordinance is null and void automaticallyCaliforniaFrom 1 Jan 2026Agency publishedGov. Code § 66326 as amended by SB 9 (Arreguín, Stats. 2025, Ch. 510), 2026-09-05
Statutory categories a city must approve ministerially regardless of its zoning4CaliforniaIn force 2026Agency publishedGov. Code § 66323(a)(1)–(4), 2026-09-07
Multifamily conversion share a city must allowAt least one unit, and up to 25 per cent of existing unitsCaliforniaIn force 2026Agency publishedGov. Code § 66323(a)(3), 2026-09-07
Detached units a city must allow on an existing multifamily lotUp to 8, not exceeding the number of existing unitsCaliforniaIn force 2026Agency publishedGov. Code § 66323(a)(4), 2026-09-07
Minimum rental term a local agency must require for the ministerial categoriesLonger than 30 daysCaliforniaIn force 2026Agency publishedGov. Code § 66323(e), 2026-09-07
Jurisdictions reporting ADU permits to HCD, 2018–2025511California2018–2025Agency publishedHCD Annual Progress Report Table A2, HCD file last updated 2026-09-04
Jurisdictions in the sixth-cycle RHNA progress file539California6th cycle to 2025Agency publishedHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05
Sixth-cycle RHNA allocation, statewide2,495,457 unitsCalifornia6th cycleAgency publishedHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05
Units permitted against that allocation so far477,627 (19.1%)California6th cycle to 2025Agency publishedHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05
ADU-adding permits in the Los Angeles analysis frame39,279City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone R1-111,730 (29.86%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone RS-14,276 (10.89%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone R1-1-RIO2,180 (5.55%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone R2-11,618 (4.12%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone RA-11,599 (4.07%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone R1V21,197 (3.05%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone R3-11,139 (2.90%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone RE11-1970 (2.47%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone RD1.5-1915 (2.33%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits in zone R1-1-CUGU887 (2.26%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share of the frame in the ten largest zone districts26,511 (67.49%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share of the frame in single-family residential zones inside that top ten22,839 (58.15%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study; zone classification is HyreADU’s
Share of the frame in multi-family zones inside that top ten3,672 (9.35%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study; zone classification is HyreADU’s
Single-family to multi-family ratio inside the top ten zones6.2×City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share of the frame outside the ten largest zone districts, unclassified here12,768 (32.51%)City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Census tracts with at least one ADU permit1,142City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Tracts producing half of all ADU permits231City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Tracts producing 80 per cent of all ADU permits526City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Gini coefficient of ADU permits across tracts0.4731City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share of permits in the busiest decile of tracts30.4%City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share of permits in the busiest quartile of tracts57.3%City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Permits in the single busiest tract190City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Median permits per tract26City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
Share of the frame in the San Fernando Valley area planning commissions53.8%City of Los Angeles2020 – 2026-08-30HyreADU calculationLADBS resource pi9x-tg5x, rows refreshed 2026-08-30 · where ADUs are built study
ADU permits as a share of all units permitted in the sixth RHNA cycle so far24.9%California6th cycle to 2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Long Beach52.1%Long BeachRHNA cycle years 2022–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Unincorporated Los Angeles County39.1%Unincorporated Los Angeles CountyRHNA cycle years 2022–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Los Angeles37.5%Los AngelesRHNA cycle years 2022–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Unincorporated San Diego County26.2%Unincorporated San Diego CountyRHNA cycle years 2022–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, San Diego19.1%San DiegoRHNA cycle years 2022–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Oakland16.0%OaklandRHNA cycle years 2024–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, San José13.6%San JoséRHNA cycle years 2024–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Sacramento9.1%SacramentoRHNA cycle years 2022–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, San Francisco6.6%San FranciscoRHNA cycle years 2024–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
ADU permits as a share of all units permitted, Fresno5.5%FresnoRHNA cycle years 2024–2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study
Spread in ADU share of permitted units between the ten focus jurisdictions52.1% (Long Beach) to 5.5% (Fresno)California, ten jurisdictions6th cycle to 2025HyreADU calculationHCD RHNA Progress Report, 6th cycle, data.ca.gov, 2026-09-05 · production against housing need study

37 HyreADU calculation · 25 Agency published · 0 Trade / survey estimate. The hub gate requires at least one third to be ours; this page is at 60 per cent.

ADU zoning figures we will not repeat

  • A count of California cities whose ADU ordinance is non-compliant

    We have seen this figure quoted with no method. Compliance findings under § 66326 belong to HCD, whose site was unreachable throughout the retrieval behind these pages, and a preemption conclusion belongs to a court.

    The ordinance tracker publishes a coding schema and two verified jurisdiction rows rather than a table of verdicts, and it explains why.

  • A normalised size, height or setback table for every California city

    Not because it would be useless — it is the single most requested ADU dataset — but because codified municipal text was not retrievable: the platform hosting most California municipal codes returned HTTP 403 to every automated request.

    A table filled from commercial ADU sites carries no ordinance number and no adoption date, and cannot be checked.

  • Our Los Angeles zone shares quoted as California figures

    58.1% and 29.9% describe one city’s zoning code. R1-1 does not exist outside Los Angeles. We hold no comparable extract with a zone field for any other jurisdiction and publish no state version of either figure.

  • A “percentage of California lots where an ADU is allowed”

    The statute makes an ADU available on lots with a proposed or existing dwelling in residential and mixed-use zones, subject to conditions that turn on the parcel.

    Converting that into a statewide parcel percentage needs a statewide parcel layer with zoning attached, which we do not hold. Where we cannot measure the denominator, we publish the rule and not a number.

  • Section 65852.2, § 66324, § 66327 or § 66332 as live citations

    All four are stale. § 65852.2 was repealed by SB 477 in March 2024.

    SB 543 renumbered § 66324 to § 66311.5, § 66327 to § 66313.5 and § 66332 to § 66311.7 with effect from 1 January 2026.

    We re-verified the Chapter 13 section list on 2026-09-07 and none of the three old numbers appears in it.

Citing these figures

Journalists and planning desks are welcome to cite these tables. Where you need the method and the limits, link the study rather than this digest: the where ADUs are built study for the geography, the ordinance tracker for the state floor and the ordinance schema, and the production against housing need study for the RHNA arithmetic.

Where a figure is labeled HyreADU calculation, attribute it to HyreADU and name the file — “HyreADU analysis of City of Los Angeles LADBS building permit data, resource pi9x-tg5x, rows refreshed 2026-08-30”, or “HyreADU analysis of HCD’s sixth-cycle RHNA Progress Report”.

Where it is Agency published, cite the Government Code section by its current number or HCD directly. Corrections go on the page with a dated note: hello@hyreadu.com.

If you take one number from this page, take this one: at least 58.15% of Los Angeles ADU permits since 2020 are in a single-family residential zone, against 9.35% in the multi-family zones inside the same top ten districts.

That is what the statute did to the zoning map, measured at the permit counter rather than argued from the text.

Questions

What zoning do you need for an ADU in California?
Broadly, the question no longer works that way. Government Code section 66319 provides that an accessory dwelling unit is an accessory use that is not counted toward the density permitted on the lot; section 66318 excludes ADUs from local residential growth limits; section 66323 requires ministerial approval of four categories of unit whatever the local ordinance provides; and section 66320 requires ministerial approval even where a city has adopted no ADU ordinance at all. What local zoning still controls is the envelope — size, height, setbacks and objective design standards — and even there the state sets a floor a city cannot go below. This describes the statute and is not legal advice about your lot.
What is the smallest maximum size a California city can impose on an ADU?
850 square feet of interior livable space, or 1,000 square feet for a unit providing more than one bedroom. Government Code section 66321(b)(2) provides that a maximum size limit must allow at least those figures. Separately, section 66321(b)(3) provides that no requirement may prevent construction of an ADU with at least 800 square feet of interior livable space and four-foot side and rear yard setbacks. Those are two different guarantees, and section 66314(d)(5) separately caps at 1,200 square feet what a city may allow for a detached unit.
How tall can an ADU be?
The state floor at section 66321(b)(4) is 16 feet for a standard detached unit; 18 feet for a detached unit within half a mile of a major transit stop or on a lot with an existing multistory multifamily dwelling, plus up to two additional feet to align the roof pitch with the primary dwelling; and 25 feet, or the local zoning height limit for the primary dwelling if lower, for an attached unit. Those are heights a city may not go below. Note that ordinances differ on the measurement basis — to the ridge, the mid-point of the roof, or the top plate — and sixteen feet measured three ways is three different buildings.
Which zones do ADUs actually get built in?
On the only complete permit record with a zone field that we hold, overwhelmingly single-family zones. In the City of Los Angeles, 11,730 of 39,279 ADU-adding permits issued since 2020 (29.86%) are in R1-1 alone, and at least 58.15% of the frame is in a single-family residential zone against 9.35% in the multi-family zones inside the same ten largest districts. The zone strings are the City’s field; the single-family classification is ours and is published so it can be checked. This is a Los Angeles figure, not a California one.
Do ADUs count toward a lot’s density limit?
No. Government Code section 66319 provides that an accessory dwelling unit that conforms to the article is deemed an accessory use or accessory building, and is not counted toward the allowable density for the lot. Section 66318 separately excludes ADUs from the residential growth limits a local agency may impose. This is the provision that makes the density question on the zoning map irrelevant to whether an ADU may be added.
Can a city refuse an ADU because its own ordinance says no?
Section 66316 provides that a non-compliant ADU ordinance “shall be null and void” and the agency applies the state standards until it adopts a compliant one, and section 66325(a) provides that the state article supersedes a conflicting local ordinance. Since 1 January 2026, section 66326 as amended by SB 9 (Arreguín, Stats. 2025, Ch. 510) adds that missing the 60-day HCD submission deadline or the 30-day response deadline voids the ordinance automatically. Whether any particular clause is non-compliant is a legal conclusion this page does not reach — ask the permitting agency in writing which standards it applies, and whether HCD has issued findings.
Do the state ADU rules apply to charter cities?
Government Code section 66312 provides that the chapter applies to a charter city notwithstanding section 65803. That is the general rule as stated in the statute; how it interacts with a particular charter provision is a legal question this page does not answer.
Can you build ADUs on multifamily property?
Yes, and section 66323 requires it in two forms. Subdivision (a)(3) requires a local agency to allow at least one accessory dwelling unit within the portions of an existing multifamily structure not used as livable space, and up to 25 per cent of the existing multifamily dwelling units. Subdivision (a)(4) requires it to allow not more than eight detached accessory dwelling units on a lot with an existing multifamily dwelling, not exceeding the number of existing units. On the Los Angeles permit record these routes are a small share of output: the three multi-family zones inside the ten largest districts carry 9.3% of the frame.
How much of California’s new housing is coming through the ADU route?
Against the sixth-cycle regional housing needs allocation, 24.9% of every unit permitted so far is an ADU — a HyreADU calculation from HCD’s own RHNA progress file, across 539 jurisdictions. That share varies enormously by jurisdiction, from 52.1% in Long Beach to 5.5% in Fresno, and cycle windows differ by council of governments so the rows are not all measured over the same number of years. A permit is not a completion, and the accessory route delivers overwhelmingly to the above-moderate income category.
Does SB 9 give me an ADU as well as a lot split?
Not automatically, and the interaction is the trap. A parcel that uses the 2021 SB 9 urban lot-split powers loses the guaranteed ADU and junior ADU right that section 66323(a)(1) would otherwise provide. That 2021 statute is a different law from the 2025 SB 9 (Arreguín) that amended section 66326 on ordinance review, and the two are routinely confused because both bear on a single-family lot. See our SB 9 study.

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 Government Code Chapter 13 retrieved from leginfo 2026-09-05, §§ 66321 and 66323 re-verified verbatim 2026-09-07; LADBS resource pi9x-tg5x rows refreshed 2026-08-30; HCD RHNA Progress Report and Annual Progress Report Table A2 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

  1. California Government Code § 66321 — size and height floors , Retrieved 2026-09-05; subdivision (b) re-verified verbatim 2026-09-07. (b)(1) no minimum square footage requirement “that prohibits an efficiency unit”; (b)(2) a maximum must allow at least “[e]ight hundred fifty square feet of interior livable space” or “[o]ne thousand square feet of interior livable space for an accessory dwelling unit that provides more than one bedroom”; (b)(3) no requirement preventing “an accessory dwelling unit with at least 800 square feet of interior livable space and with four-foot side and rear yard setbacks”; (b)(4) heights of 16 feet detached, 18 feet transit-adjacent or on a multistory multifamily lot, and 25 feet or the local limit whichever is lower for an attached unit. Enactment line: “Amended by Stats. 2025, Ch. 520, Sec. 5. (SB 543) Effective January 1, 2026.” Retrieved 2026-09-07.
  2. California Government Code § 66323 — the ministerial approval categories , Retrieved 2026-09-05; re-verified verbatim 2026-09-07. (a)(1) one ADU and one junior ADU per lot with a proposed or existing single-family dwelling; (a)(2) one detached new-construction ADU at four-foot side and rear yard setbacks, with an optional floor area limitation of “not more than 800 square feet”; (a)(3) multiple ADUs within the portions of an existing multifamily structure not used as livable space, at least one and “up to 25 percent of the existing multifamily dwelling units”; (a)(4) “not more than eight detached accessory dwelling units” on a lot with an existing multifamily dwelling, not exceeding the number of existing units; (e) a minimum rental term longer than 30 days. Enactment line: “Amended by Stats. 2025, Ch. 520, Sec. 6. (SB 543) Effective January 1, 2026.” Retrieved 2026-09-07.
  3. California Government Code § 66314 — required contents of a local ADU ordinance , Retrieved 2026-09-05. (b)(1) objective standards “that include, but are not limited to, parking, height, setback, landscape, architectural review, maximum size of a unit”; (d)(4) an attached unit “shall not exceed 50 percent of the existing primary dwelling”; (d)(5) a detached unit “shall not exceed 1,200 square feet”; (d)(7) “Setback of no more than four feet from the side and rear lot lines”. Amended by Stats. 2025, Ch. 67, Sec. 109 (AB 1170), effective 1 January 2026. Retrieved 2026-09-05.
  4. California Government Code, Title 7, Division 1, Chapter 13 — the full section list , Re-verified 2026-09-07. Confirms the current numbering of §§ 66310 to 66342 and the subject matter of each: 66312 charter cities; 66316 non-compliant ordinance null and void; 66317 ministerial approval and the 60-day deadline; 66318 zoning amendment and exclusion from growth limits; 66319 accessory use, not counted toward density; 66320 no ordinance adopted; 66325 supersession and less restrictive local rules; 66326 HCD ordinance review. Also confirms that §§ 66324, 66327 and 66332 no longer appear in the chapter, having been renumbered to §§ 66311.5, 66313.5 and 66311.7 by SB 543 (Stats. 2025, Ch. 520) with effect from 1 January 2026. Retrieved 2026-09-07.
  5. City of Los Angeles Department of Building and Safety — Building Permits Issued from 2020 to Present , Open data resource pi9x-tg5x on data.lacity.org. 409,619 rows downloaded; rows refreshed 2026-08-30. Frame: permits adding a net ADU or junior ADU, supplemental permits excluded, issue year 2020 or later — 39,279 records, of which 39,279 carry a census tract. Zone-district counts, tract concentration measures, area planning commission shares and the Gini coefficient on this page are HyreADU calculations from that extract, not figures published by the City. The classification of zone districts into single-family and multi-family is HyreADU’s. Retrieved 2026-08-31.
  6. California HCD — RHNA Progress Report, 6th cycle , Open dataset on data.ca.gov, resource 1e80a9cf-724c-432d-8374-e9708a6a92dc, HCD file last updated 2026-09-04, retrieved 2026-09-05. 539 jurisdictions; allocation 2,495,457 units; 477,627 units permitted so far (19.1%). ADU share of units permitted and every per-jurisdiction share on this page are HyreADU calculations from that file. Retrieved 2026-09-05.
  7. California HCD — Housing Element Annual Progress Report, Table A2 , Full Table A2 extract, HCD file last updated 2026-09-04, retrieved 2026-09-05. Cited here for the count of jurisdictions reporting ADU permits between 2018 and 2025 — 511 — which is the denominator behind any claim about how widely the accessory route is being used across California. Retrieved 2026-09-05.

The zoning map stopped being the answer. The envelope did not.

What a California lot will hold is now a question about size, height and setbacks rather than about the district it sits in. The envelope calculator works from the state floor and whatever local standard you can verify.

Size and envelope calculator The ordinance tracker

HyreADU does not design, permit or build accessory dwelling units and does not practice law. This page is informational and is not legal advice.

Statutory text is quoted as retrieved on 5 September 2026, with sections 66321(b) and 66323 and the Chapter 13 section list re-verified on 7 September 2026; California’s ADU chapter has been recodified twice since March 2024 and section numbers in older guidance are frequently stale.

This page names no jurisdiction as non-compliant, because compliance findings under section 66326 belong to the Department of Housing and Community Development.

Zone-district, tract and area figures are HyreADU calculations from a City of Los Angeles open dataset and describe that city only; the classification of zone districts into single-family and multi-family is a HyreADU judgment, published in the table so it can be checked.

No rate per eligible parcel is published, because no parcel-level denominator is held — every share here is a share of permits. RHNA shares are computed over cycle windows that differ by jurisdiction and are not directly comparable between rows.

A permit is not a completion, and neither is a measure of affordability.