Can I build an ADU in Aurora?
✓ Verified against code · August 19, 2026
Under the city's code as written: only a detached, 650 sq ft ADU on an alley-served lot in the Original Aurora subdistricts, through a public hearing, with the owner living on site. State law (C.R.S. 29-35-403) has required much more since June 30, 2025, and the state formally flagged Aurora as non-compliant in October 2025 — but the code hasn't been amended, so expect friction at the counter and get anything the city tells you in writing.
Citation: UDO §146-3.3.6.G; DOLA Oct 2025 determination
How current is this?
Aurora’s ADU rules run under UDO §146-3.3.6.G (2018-era rules carried into the 2019 UDO) (No HB24-1152 compliance ordinance exists). Aurora is the state's highest-profile ADU holdout: its council voted a staff-drafted compliance ordinance down 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. Where the code conflicts with C.R.S. 29-35-403, state law controls on paper — but the city's counter still applies its own code, and only 9 ADUs have been permitted since 2018. We verified this answer against primary sources on August 19, 2026, and every change we catch is logged in the changelog.
More Aurora ADU questions
- Is Aurora breaking Colorado's ADU law?
- When will Aurora's ADU rules change?
- Does Aurora's lawsuit against the state cover ADUs?
All Aurora ADU rules → · Compare Colorado cities →
Not legal advice — lot-specific overlays can change the answer for your parcel. The citation above points at the governing code section; check it, or ask the city to confirm.