ADU rules change faster than the answers about them.
States keep rewriting accessory dwelling unit law, cities keep adopting — and most guides and AI answers lag the code by months or years. ADU Ledger tracks the rules city by city, cites every fact to the current municipal code section, and logs every change in public.
Washington · HB 1337 (2023) · 16 cities · compare →
Bellevue
LUC 20.20.120 (Land Use Code)
Rules current since Mar 2024Bothell
BMC 12.14.135 (Bothell Municipal Code)
Rules current since Jul 2025Burien
BMC 19.17.070 (Burien Municipal Code, post-Ordinance 868)
Rules current since Jun 2024Edmonds
ECDC 16.20.060 (Edmonds Community Development Code)
Rules current since Jul 2025Everett
EMC 19.08.100 Table 8-6, under the Everett 2044 zoning (NR / NR-C)
Rules current since May 2025Issaquah
LUC 18.500.090 (Issaquah Land Use Code)
Rules current since Jul 2025Kent
KCC 15.08.350 (Kent City Code)
Rules current since Jun 2025Kirkland
KZC 115.07 (Kirkland Zoning Code)
Rules current since Jul 2025Lynnwood
LMC Title 8 (Unified Development Code) — no standalone ADU section
Rules current since Dec 2025Olympia
OMC 18.04.060 (Olympia Municipal Code)
Rules current since Jun 2025Redmond
RZC 21.04.1110 (Redmond Zoning Code, post-Redmond 2050 restructure)
Rules current since Jun 2025Renton
RMC 4-2-110C (Renton Municipal Code)
Rules current since Jan 2025Sammamish
SMC 21.05.010.C(5) / 21.04.030.C (Sammamish Municipal Code)
Rules current since Jan 2026Seattle
SMC 23.42.022 and the new Chapter 23.44 (Neighborhood Residential)
Rules current since Jan 2025Shoreline
SMC 20.40.210 (Shoreline Municipal Code)
Rules current since Feb 2025Tacoma
TMC 13.06.080.A, under the Home in Tacoma Phase 2 zoning (UR-1/UR-2/UR-3)
The Washington staleness clock
- Mar 2024BothellBothell adopted its core ADU rewrite in March 2024, then kept going: a December 2024 amendment, and in July 2025 Ordinance 2461 repealed minimum off-street parking citywide and capped ADU impact fees at half the principal-unit rate.
- Jun 2024EdmondsEdmonds complied with HB 1337 a full year early — Ordinance 4360 took effect June 19, 2024 — then reshaped the details again in mid-2025 with its middle-housing rezone (Ord 4397) and a follow-up amendment (Ord 4398).
- Jan 2025SammamishSammamish's Title 21 rewrite (Ord O2024-578) took effect January 1, 2025 — six months ahead of the state deadline.
- Jan 2025ShorelineShoreline rewrote its ADU section in January 2025 (Ord 1027), then went further than the state ever asked in August 2025: Ordinance 1043 eliminated minimum vehicle parking requirements for everything, citywide.
- Feb 2025TacomaHome in Tacoma Phase 2, effective February 1, 2025, replaced Tacoma's single-family zoning with Urban Residential zones and folded detached ADUs into the 'Backyard Building' housing type.
- May 2025IssaquahIssaquah adopted its ADU package (Ord 3092) and parking overhaul (Ord 3093) together in May 2025, alongside its middle-housing ordinance.
- Jun 2025KirklandKirkland's 2025 middle-housing and state-conformance ordinances (O-4905, O-4913) updated KZC 115.
- Jun 2025RentonRenton adopted its HB 1337 compliance package in June 2025 (Ord 6160) and amended it again five months later (Ord 6173, November 2025) — two rule changes in one year.
- Jun 2025RedmondThe Redmond 2050 restructure (Ord 3220, effective June 28, 2025) moved ADU rules from RZC 21.
- Jul 2025BellevueDetached ADUs were prohibited entirely in Bellevue until Ordinance 6851 (adopted June 24, 2025, effective early July 2025).
- Jul 2025LynnwoodLynnwood didn't amend its ADU code — it replaced its entire development code.
- Jul 2025EverettThe Everett 2044 periodic update, effective July 8, 2025, rewrote Title 19, deleted the owner-occupancy requirement, and abolished the old R-S/R-1/R-2 zones — any source citing those zones is describing a code that no longer exists.
- Jul 2025BurienOrdinance 868 — Burien's comprehensive Title 19 rewrite for HB 1110/1337 — took effect July 9, 2025.
- Jul 2025KentKent's ADU rules came in two waves — a 2023 liberalization (Ord 4464) and the ReCode Kent package effective July 30, 2025 (Ord 4517) — with the zone charts reworked again in April 2026 (Ord 4536).
- Dec 2025OlympiaOlympia adopted its combined HB 1110/1337 package in November 2025 — about five months after the state deadline — making its rules the freshest of the region's major cities.
- Jan 2026SeattleSeattle rewrote its residential zoning twice in eight months: the HB 1337 compliance package (Ord 127211, May 2025), then the permanent state-compliance code signed December 22, 2025 and effective January 21, 2026, which repealed the old Chapter 23.
Colorado · HB24-1152 (2024) · 12 cities · compare →
Arvada
Land Development Code §5-1-5-2
Rules current since Sep 2019Aurora
UDO §146-3.3.6.G (2018-era rules carried into the 2019 UDO)
Rules current since Mar 2025Boulder
B.R.C. 9-6-3(n) (Boulder Revised Code)
Rules current since Apr 2025Colorado Springs
UDC 7.3.304E (City Code Ch. 7)
Rules current since Dec 2024Denver
Denver Zoning Code §11.8.2 and Article 3/5 form standards
Rules current since Feb 2025Fort Collins
Land Use Code §3.1.8 and zone-district standards
Rules current since Feb 2023Greeley
Greeley Municipal Code Title 24 (Development Code), §24-403
Rules current since Jul 2024Lakewood
Zoning Ordinance Title 17, §17.4.3.1 (pre-rewrite code, restored by voter repeal)
Rules current since Jun 2025Longmont
LMC 15.02.080.E (Longmont Municipal Code)
Rules current since Aug 2025Pueblo
PMC 17-4-16 (Pueblo Municipal Code)
Rules current since Sep 2025Thornton
Development Code §18-339 (reenacted Chapter 18)
Rules current since Jan 2025Westminster
WMC 11-4-19 (Westminster Municipal Code)
The Colorado staleness clock
- Sep 2019AuroraAurora is the state's highest-profile ADU holdout: its council voted a staff-drafted compliance ordinance down 6–2 in June 2025, the state formally identified Aurora as non-compliant with the ADU law in October 2025, and as of August 2026 the codified rules are still the restrictive 2018 regime.
- Mar 2022ArvadaArvada's ADU framework dates to its 2022 code and was amended in August 2025 — after the state deadline — without fixing the provisions that appear to conflict with Colorado's ADU statute: ongoing owner-occupancy with a deed restriction, a blanket parking mandate, and size caps that dip below the statute's protected range.
- Feb 2023GreeleyGreeley's ADU rules predate Colorado's ADU statute and haven't been amended since February 2023.
- Jul 2024LakewoodLakewood is the cautionary tale of the Front Range: the city replaced its entire zoning code in fall 2025, the new code was operative for exactly twelve days (January 1–12, 2026) before certified referendum petitions suspended it, and voters repealed all four rewrite ordinances by ~62.
- Dec 2024DenverDenver's citywide ADU ordinance (CB24-1302) ended parcel-by-parcel rezonings in December 2024, a follow-up repealed all vehicle-parking minimums citywide in August 2025, and a February 2026 amendment forced PUDs to allow ADUs.
- Jan 2025WestminsterWestminster complied six months early (January 1, 2025) with clean, statute-shaped rules — then amended once more in March 2026 (Ordinance 4335, at the state's insistence) to guarantee small-home owners the statutory 750 sq ft.
- Feb 2025Fort CollinsAfter the 2022–23 land-use-code repeal saga, Fort Collins re-adopted its code in May 2024 and rewrote the ADU rules for state compliance effective February 14, 2025 (Ordinance 009-2025).
- Mar 2025BoulderBoulder spent two decades as one of the country's most ADU-restrictive cities and unwound it in stages: the per-block saturation caps died in September 2023 (Ord 8571), and owner-occupancy ended March 8, 2025 (Ord 8650).
- Apr 2025Colorado SpringsColorado Springs adopted on time — and pushed back on purpose.
- Jun 2025LongmontLongmont adopted its state-compliance rewrite in June 2025 and amended it again in December.
- Aug 2025PuebloUntil August 25, 2025, new ADUs were prohibited in Pueblo entirely — only units 'established' before February 1968 were recognized.
- Sep 2025ThorntonThornton reenacted its entire Development Code effective September 1, 2025 — mostly statute-shaped, with one glaring exception: it kept an ongoing owner-occupancy requirement enforced by a recorded deed restriction, which Colorado's ADU statute has barred for cities like Thornton since June 30, 2025.
More cities are in verification and are added only after a full adversarial fact-check. How we verify →
Analysis
Colorado ADU compliance scorecard
Which Front Range cities actually comply with HB24-1152 — including three the state lists as non-complying.
What changed · Jan 2026Seattle now counts ADUs against FAR
The repealed exemption most guides — and most AI answers — still cite.
What changed · Apr 2026Lakewood’s twelve-day zoning code
Voters repealed the entire rewrite. Here’s what actually governs now.
Latest from the changelog
Versioned rules, anchored facts, and open data
Three structural upgrades. First: rules now carry their history in the data itself — where we've verified a superseded rule, the city page shows 'Previously: … changed by [ordinance, date]' right under the current rule (nine facts to start: Seattle's FAR change, Bellevue's DADU legalization, Everett's and Boulder's owner-occupancy removals, Denver's rezoning-era end and parking repeal, Tacoma's 2019 parking elimination, Colorado Springs' height cut, Lakewood's 2024 size increase). Second: every rule row is now individually addressable (aduledger.com/wa/seattle#coverage). Third: the full corpus is downloadable at /data as JSON and CSV under CC BY 4.0 — use it, cite us.
aduledger.com goes live; compliance scorecard and change-analysis pages published
The site moved to its permanent domain (aduledger.com; old URLs redirect). New: the Colorado ADU Compliance Scorecard — a city-by-city grading of HB24-1152 compliance including the three cities the state lists as non-complying — and two 'what changed' analyses: Seattle's January 2026 FAR change (which most published guides and AI answers still get wrong) and Lakewood's twelve-day zoning code. City pages also now carry Legislation and Dataset structured data alongside the existing FAQ and Article markup. Our day-zero baseline measurement is on record: this site is absent from all tracked search results, and 50% of the top-ranking answers to our sampled questions are stale or incorrect against the verified corpus. That is the gap this ledger exists to close — watch this changelog.
Colorado joins the ledger: eleven Front Range cities, cited to code
Denver, Aurora, Colorado Springs, Pueblo, Thornton, Westminster, Arvada, Boulder, Longmont, Fort Collins, and Greeley — the HB24-1152 (C.R.S. 29-35-401–405) landscape, verified against adopted ordinances and codified text, with an adversarial fact-check of a load-bearing claim per city before publication (7 confirmed, 4 corrected). The compliance picture is messier than Washington's: the state formally listed Aurora, Thornton, and Arvada as non-complying in October 2025; Colorado Springs adopted on time while asserting home-rule authority to be stricter; Pueblo adopted under a state extension; Greeley's code appears to conflict with the statute yet escaped the state's list. Lakewood follows shortly — see its own entry.