Accessory Structures in Aurora, CO

If you live in Aurora or are thinking about moving there, accessory structures are one of those things you probably won't think about until they affect you directly. Aurora has 5 specific rules on the books covering different aspects of accessory structures, and some of them might surprise you.

Tiny Homes

Aurora, Colorado treats tiny houses as manufactured housing under its Unified Development Ordinance, restricting them to the R-MH Manufactured Home Park zone district with foundation, utility and minimum-area rules.

Key details: Zoning: R-MH district only. Wheels: Must be removed. Foundation: Permanent foundation required. Utilities: Water, sewer, electric before 30 days. Min. area: 1,000 sq ft or 1.5x floor area.

Noncompliant installation is a UDO violation subject to a notice of violation, stop-work order, withheld permits or certificate of occupancy, permit revocation, and summons to Aurora Municipal Court for uncorrected violations.

Compared to other cities, Aurora takes a harder line on tiny homes. The enforcement and penalty structure reflects that.

ADU Rules

Aurora allows one detached accessory dwelling unit per single-family lot, but only on alley-served lots over 6,000 square feet, capped at 650 square feet.

Key details: Units allowed: 1 detached ADU per lot. Lot requirement: Alley-served, over 6,000 sq ft. Max size: 650 square feet. Max height: 24 feet. Parking: 1 extra alley-accessed space.

Building without meeting these standards risks a stop-work order and denial of the permit/certificate of occupancy through Aurora's standard development review process; owner-occupancy and short-term-rental terms are enforced through code compliance.

Shed & Carport Rules

Aurora requires a detached carport that needs a building permit to sit in the rear or side yard, meet zone setbacks, and match the main house's exterior materials.

Key details: Placement: Rear or side yard only. Rear setback: 5 ft (3 ft from alley). Materials: Must match main house. Open carport exception: Can reach 5 ft of side line. Permit: Building permit required.

Building a detached carport without a permit, or outside the required rear/side yard and setback limits, violates the UDO and can bring a stop-work order, code-enforcement citation, and forced relocation or removal of the structure.

ADU Owner Occupancy

Aurora's Unified Development Ordinance requires the property owner to live in either the primary house or the detached accessory dwelling unit: a backyard ADU can't be a pure rental with an absentee owner.

Key details: Occupancy rule: Owner must live in one unit. Max ADU size: 650 square feet. Max ADU height: 24 feet. Lots allowed: Alley-served, one ADU per lot. STR use: Only if owner occupies primary home.

Operating a detached ADU without owner-occupancy, or subdividing the lot to separate the ADU from the primary dwelling, is a zoning violation the City can enforce through code enforcement and permit revocation.

ADU Rental Restrictions

Aurora's UDO allows a backyard accessory dwelling unit to be rented short-term only if the property owner lives in the primary house; City Code caps entire-home short-term rentals at 180 days a year but exempts owner-occupied ADUs.

Key details: ADU size cap: 650 sq ft, one per lot. STR condition: Owner must occupy primary structure. Whole-home STR cap: 180 days per year (ADU exempt). Licensing: City business + lodger's license required. Booking-service penalty: $1,000 per violation per day.

Advertising or operating a short-term rental without a city business and lodger's license, exceeding the 180-day cap on a non-owner-occupied dwelling, or renting an ADU short-term while the owner lives elsewhere is unlawful; booking services face $1,000/day civil penalties.

The Bottom Line

Aurora's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Aurora is broadly strict or permissive.

This guide is based on Aurora's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.