Arvada ADU rules
✓ Verified against code · August 19, 2026
Current rules under Land Development Code §5-1-5-2, adopted by 2022 LDC (Ord 4793), amended by Ord 4905, in effect since March 21, 2022. Arvada'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. The state's October 2025 compliance review listed Arvada among the non-complying jurisdictions.
Common questions, answered from the code
Is Arvada's ADU code compliant with state law?
The state says no: Colorado's October 2025 compliance review listed Arvada as non-complying. The specific conflicts: ongoing owner-occupancy enforced by deed restriction, a blanket one-space parking mandate, and a 600 sq ft cap on small lots — inside the 500–750 sq ft range the statute protects. The August 2025 code amendment left all three in place. State law controls on paper, but expect the counter to apply the city's code; get positions in writing.
DOLA Oct 2025; LDC §5-1-5-2.D, .E, .K–.L · Permalink
How big can an Arvada ADU be?
It depends on your lot: 600 sq ft on lots up to 6,000 sq ft, stepping up to 1,200 sq ft on lots over an acre — but never more than 40% of the home's living space. Note the small-lot cap conflicts with the state statute's 750 sq ft protection, which is part of the state's non-compliance finding.
LDC Table 5-1-5-2 · Permalink
How long does an Arvada ADU permit take?
The city publishes targets: about 3 weeks of review for a detached ADU, 1–2 weeks for an interior or attached one — administrative, through the eTRAKiT portal, with a licensed contractor required.
City ADU page · Permalink
Can my Arvada ADU have its own water meter?
No — the code requires the ADU to share the principal dwelling's water and sewer services. That cuts utility connection costs but matters for landlords who want separate billing.
LDC §5-1-5-2.I · Permalink
The rules at a glance
| ADUs allowed per lot | One ADU per lot with a single-family detached home, in residential, OT, and MX districts — either Type A (detached) or Type B (interior/attached with separate access), not both.LDC §5-1-5-2.A, .C, .G |
| Maximum size | The lesser of 40% of the home's living space and a lot-size tier: 600 sq ft on lots up to 6,000 sq ft; 850 up to 12,499; 1,000 up to an acre; 1,200 beyond. The 600 sq ft tier sits inside the 500–750 sq ft range state law protects — an apparent conflict. In-footprint conversions may reach 50% of the home including basement.LDC §5-1-5-2.E, Table 5-1-5-2; contrast C.R.S. 29-35-402(18) |
| Detached ADU height | 25 ft in most RN subdistricts; 30 ft in RN-32.5, R6, R13, R24, and MX districts.LDC Table 2-1-3-3A (rows added by Ord 4905) |
| Detached ADU setbacks | Principal-dwelling standards: RN interior side 5–15 ft, rear 10–15 ft by subdistrict — and zero rear setback where the lot abuts an alley. A detached ADU must sit at or behind the house's front plane (10 ft behind the façade on both frontages of a corner lot).LDC §5-1-5-2.B, .F; Table 2-1-3-3A |
| Off-street parking | One on-site space required for the ADU, in addition to the home's parking (tandem allowed) — broader than the narrow case where state law permits requiring a new space.LDC §5-1-5-2.D.1–2; contrast C.R.S. 29-35-403(3) |
| Owner-occupancy | Still required, ongoing: the owner must occupy the house or the ADU, enforced by a recorded deed restriction that ties the ADU's certificate of occupancy to continued owner occupancy and bars separate sale. State law has barred ongoing owner-occupancy requirements since June 30, 2025; Arvada's August 2025 amendment left this in place.LDC §5-1-5-2.K, .L; contrast C.R.S. 29-35-403(2)(b) |
| Lot coverage / floor area | District standards apply (RN lot coverage 25–40% by subdistrict); in the OT district the ADU footprint is capped at the lesser of 800 sq ft or 40% of the house's footprint.LDC §5-1-5-2.B; Table 2-1-5-10B |
| Permit path & timeline | Administrative building permit via eTRAKiT, with a licensed contractor required. Published review timelines — rare and welcome: about 3 weeks for a detached (Type A), 1–2 weeks for an interior/attached (Type B).City ADU page; LDC §3-1-2-1.B |
Worth knowing
- ADU utilities must share the home's water and sewer services — no separate taps allowed (the opposite of Everett, WA's separate-meter mandate).
- One short-term rental per property; the ADU may be the licensed STR unit.
- The city's page notes HOA approval — though state law limits HOA ADU bans.
- Closing out the permit takes more than inspections: an improvement location certificate, grading certification, blower-door test, and recorded covenants are all required.
- Arvada is a plaintiff in the six-city home-rule lawsuit — but that case targets other housing laws, not the ADU statute it currently conflicts with.
On our watchlist
No corrective ordinance found through August 2026 (the only 2026 LDC amendment covered short-term rentals) — the state-conflict provisions are the top watchlist item.
The six-city home-rule lawsuit (other statutes) remains pending.
Check your parcel
The rules above are citywide — what you can build depends on your lot’s zone, size, and setbacks. Look yours up on the official viewers:
Primary sources
Other Colorado cities
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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. Spotted an error or a new ordinance? See about to reach us; corrections are logged in the changelog.