Denver vs. Lakewood ADU rules
Denver and Lakewood are both easy places to build, but the numbers differ. Denver's DZC §11.8.2.1.B.2 caps single-unit-district ADUs at an 864 sq ft footprint (1,000 sq ft on lots over 7,000 sq ft), while Lakewood's June 2024 compliance amendment (O-2024-12) allows 1,400 sq ft of gross floor area, the most generous flat cap on the Front Range. Denver dropped all vehicle-parking minimums citywide in August 2025; Lakewood still requires one space if on-street parking is legally or practically unavailable. Lakewood's administrative review is unusually fast — a 15-day decision clock — while Denver publishes no fixed timeline.
✓ Verified against code · August 19, 2026
Denver rules run under Denver Zoning Code §11.8.2 and Article 3/5 form standards, adopted by CB24-1302 (amended by CB25-0684, CB25-2163), in effect since December 16, 2024.
✓ Verified against code · August 19, 2026
Lakewood rules run under Zoning Ordinance Title 17, §17.4.3.1 (pre-rewrite code, restored by voter repeal), adopted by O-2024-12 (the fall-2025 rewrite was repealed by voters April 7, 2026), in effect since July 10, 2024.
Rule by rule
| Rule | Denver | Lakewood |
|---|---|---|
| ADUs allowed per lot | One ADU per primary dwelling unit; in single-unit (SU) districts, one per zone lot, attached or detached. ADUs accessory to two-unit or multi-unit primaries must be detached.DZC §11.8.2.1.A.1–.2Previously: ADUs required a parcel-by-parcel rezoning through city council — changed by CB24-1302, effective Dec 16, 2024 | One ADU per lot, accessory to a single-family home — attached, detached, or over a garage. The old 9,000 sq ft minimum-lot rule was deleted in 2024. Allowed as a limited use in all R districts (and inside the permitted use's building in several mixed/commercial districts); prohibited in the industrial districts.§17.4.3.1.A.1, .3, .8–.11; Table 17.4.1 |
| Maximum size | SU districts: building footprint capped at 864 sq ft on lots of 7,000 sq ft or less, 1,000 sq ft on larger lots — footprint, not floor area, so a two-story unit can roughly double the space. Non-SU attached ADUs: up to the greater of 75% of the primary's floor area or 864 sq ft.DZC §11.8.2.1.B.2; §5.3.4.5 | 1,400 sq ft of gross floor area — the most generous flat cap on the Front Range, raised from 700 sq ft (with a one-bedroom cap, also deleted) by the June 2024 amendment. This generous cap predates the repealed rewrite and survives it.§17.4.3.1.A.6.a (O-2024-12)Previously: 700 sq ft with a one-bedroom cap — changed by O-2024-12, adopted June 10, 2024 |
| Detached ADU height | Urban contexts: 2 stories / 24 ft with a side-lot-line bulk plane (12 ft on lots ≤40 ft wide, then 45°). Suburban: 1 story/17 ft, or 2 stories/24 ft with a 20-ft rear setback. The ADU must sit in the rear 35% (urban) or 50% (suburban) of the lot.DZC §5.3.4.5 form tables | The code conflicts with itself: Article 4 says 30 ft, Article 5's table says 20 ft (30 ft over a detached garage). The code's own rule that the more restrictive provision governs makes the effective answer 20 ft, or 30 ft over a garage — but get the city's reading in writing.§17.4.3.1.A.5.b vs. Table 17.5.1; §17.1.6.2.A |
| Detached ADU setbacks | Urban: side 3 ft (lots ≤40 ft) or 5 ft; rear 5 ft without an alley — with an alley, 5 ft if garage doors face it, 0 ft if they don't. Suburban: side 3/5/7.5 ft by lot width; rear 10 ft (one story) or 20 ft (two). Vehicle access must come from the alley where one exists.DZC §5.3.4.5; §11.8.2.1.C.1 | Another internal wrinkle: the ADU section points at primary-structure standards (front 25 / side 15-10-5 / rear 15 ft in R districts), while the accessory-structure table gives 10 ft side/rear in the large-lot districts and 5 ft elsewhere, behind the front edge of the house. Large structures (any wall over 32 ft long or 12 ft high) take primary setbacks. The ADU can't sit in front of the house.§17.4.3.1.A.5; Table 17.5.1; §17.5.5.1 |
| Off-street parking | None. Denver repealed all minimum vehicle parking requirements citywide effective August 11, 2025.CB25-0684; DZC Div. 10.4Previously: Minimum vehicle parking applied per zone — changed by CB25-0684, effective Aug 11, 2025 | Conditional: parking applies only if on-street parking is 'legally or practically unavailable' (arterial/collector frontage, streets under 28 ft, or posted no-parking) — then one space per unit. Since June 30, 2025, the state statute further limits when a new space can be demanded; treat the statute as controlling where more permissive.§17.4.3.1.A.6.e; Table 17.8.1; C.R.S. 29-35-403(3) |
| Owner-occupancy | No ongoing occupancy requirement. In SU districts, both units must stay under common ownership, and an owner must occupy the primary home at the time of permit application when adding an ADU to an existing house (waived for simultaneous new construction and DHA properties) — the exact carve-out state law allows.DZC §11.8.2.2.A–.B; C.R.S. 29-35-403(2)(b) | Permit-issuance only: an ADU permit issues to an owner-occupant or their designee — no ongoing occupancy requirement and no recorded covenant (the 2024 amendment deleted both). Consistent with the state statute's application-time allowance.§17.4.3.1.A.4 (O-2024-12); C.R.S. 29-35-403(2)(b) |
| Lot coverage / floor area | A detached ADU counts toward the primary form table's maximum building coverage (Urban House: 60/45/40% by lot width). No ADU-specific bonus.DZC §5.3.4.5; Art. 5 form tables | Accessory structures combined: at most 50% of the rear/side/non-primary-front yard area and 10% of the total lot; zone minimum open space runs 25–65% by district.§17.5.5.1.B.1; Table 17.5.1 |
| Permit path & timeline | Use by right citywide where single-unit dwellings are allowed — no rezoning since December 2024. Zoning permit + building permit + sewer use & drainage permit; a licensed contractor is required (homeowners can't self-permit). No fixed timeline — the city publishes only a live average-review-times dashboard.CB24-1302; Denver CPD ADU permits page | Administrative Review of Supplemental Standards (no hearing, no public input) — and the director must decide within 15 days of a complete application, one of the fastest codified clocks anywhere — plus residential design standards and the building permit.§17.4.3.1.A.7; §17.2.12.2.B.2 |
Denver: worth knowing
- Carriage-lot ADUs are allowed without any primary dwelling — rare anywhere.
- The WDSF+ pilot (Denver Housing Authority / West Denver Renaissance Collaborative) offers design and finance support for income-restricted-rent ADUs, expanded citywide.
- Short-term renting an ADU requires the host to live in the primary structure (Denver's STR primary-residence rule).
- Denver is not on the state's certified ADU-supportive-jurisdiction list, so it doesn't participate in the HB24-1152 fee-reduction grant program.
- A rooftop deck up to 100 sq ft is allowed on alley-adjacent ADUs; no tiny-homes-on-wheels or RVs.
Denver: on our watchlist
The at-application owner-occupancy rule for existing-house ADUs draws ongoing criticism and is a likely future amendment target; nothing is filed after CB25-2163 (Feb 2026).
Lakewood: worth knowing
- The repealed rewrite would have kept the 1,400 sq ft cap — the headline number was never actually at stake; the fight was over the rest of the code.
- The 'similar in appearance' design rule (materials, color, roof pitch matching the house) sits in unresolved tension with the state statute's design-standard limits.
- Waivers of ADU standards are possible only through the major-waiver process before the Planning Commission.
- The city charter bars council from re-adopting the repealed ordinances for six months (until about October 7, 2026) — expect a new zoning effort after that.
- Whatever was permitted under the new code during its twelve days in force (January 1–12, 2026) sits in undocumented territory.
Lakewood: on our watchlist
The charter's six-month re-adoption bar lifts around October 7, 2026 — a new zoning effort is likely after that; this page's framework could change again.
O-2024-12's exact effective date is pinned to ~July 2024 by charter math; the ordinance PDF itself is bot-blocked (manual download would confirm).
The internal height and setback contradictions await a city determination; we publish both readings rather than pick one.
Full detail: Denver · Lakewood · back to the Colorado hub. Not legal advice — every fact above cites the code section it comes from; check the cite, or ask your city’s planning department to confirm your specific lot.