Arvada's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Arvada, Colorado, there are 3 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Shed & Carport Rules

Arvada splits backyard structures into two size classes. Small sheds, playhouses and gazebos under 200 square feet and 12 feet tall qualify as "mini-structures" under Section 5-1-4-3 and need no building permit, capped at two per lot and barred from front yards. Larger storage sheds and detached garages fall under Section 5-1-5-3's accessory-building rules, which require a permit and setback compliance.

Key details: Mini-structure max size: 200 sq ft. Mini-structure max height: 12 ft (except tree houses). Mini-structures per lot: 2 maximum. Barns/stables permitted zones: RA and RN-32.5 only. Accessory buildings, RN-4 lots: 2 maximum.

An accessory building erected without the required permit, sized over the zone's accessory-building cap in Table 5-1-5-3A, or placed in a prohibited front or side yard is a Code violation under Section 10-1-2-1. The City may issue a stop-work order, deny or revoke related permits, or seek abatement in Arvada Municipal Court under Section 10-1-2-2; an uncorrected violation is a misdemeanor under Section 10-1-2-3 with a fine under Section 1-5 or up to 180 days in jail.

ADU Owner Occupancy

Arvada requires the property owner to live in either the principal home or the accessory dwelling unit under Land Development Code Section 5-1-5-2.K. The Director can waive the rule for documented absences under one year, but only after the owner has held the permit for at least two years, and the requirement is locked in through a deed restriction recorded before the building permit issues.

Key details: Owner-occupancy waiver: Absence under 1 year, after 2 years of use. ADUs per lot: One ADU allowed per residential lot. Deed restriction: Filed with County Clerk before building permit. Max fine: $2,650 per violation under Section 1-5. Governing section: LDC Section 5-1-5-2.K, Owner Occupancy.

Operating an ADU without the owner living in either unit, or without the recorded deed restriction, violates the LDC and can void the ADU's certificate of occupancy. Under Section 10-1-2-2, a person who ignores a notice of violation or stop-work order is guilty of a misdemeanor punishable by a fine up to the Section 1-5 limit of $2,650, imprisonment up to 180 days, or both, with each day of continued noncompliance charged as a separate offense.

ADU Rules

Arvada allows one accessory dwelling unit with every single-family detached home in residential, OT and MX zoning districts under Land Development Code Section 5-1-5-2, capped at 40 percent of the principal home's living space and a lot-size-based maximum from 600 to 1,200 square feet. Every ADU needs one added on-site parking space, and a garage built for the ADU cannot exceed 250 square feet.

Key details: ADU allowed with: Single-family detached homes only. Zoning districts: Residential, OT and MX districts. Max size vs. principal home: 40% of principal living space. Size cap, lots ≤6,000 sf: 600 sq ft. Size cap, lots >1 acre: 1,200 sq ft.

Building an ADU larger than the Table 5-1-5-2 cap, skipping the required extra parking space, or exceeding the 250-square-foot ADU garage limit violates LDC Section 10-1-2-1(A)(1). The Director can withhold the certificate of occupancy until the unit conforms, and continued noncompliance is a misdemeanor under Section 10-1-2-3, punishable by a fine up to the Section 1-5 cap of $2,650 and/or 180 days in jail.

The Bottom Line

Arvada'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 Arvada is broadly strict or permissive.

All of the above reflects Arvada's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.