ADU rules in Parker

Parker bans accessory dwelling units outright. Land Development Ordinance Section 13.05.050(d)(1) reads, in full, 'Accessory dwelling unit. Accessory dwelling units are prohibited in all districts,' and Table 13.05.A in Section 13.05.020 carries a single 'Not permitted' cell spanning all eighteen base zoning districts for the use 'Dwelling Unit, Accessory.' The LDO definition reaches any subordinate unit 'added to, created within, or detached from' a single-family detached dwelling and expressly includes detached structures whether stick-built, prefabricated, modular, manufactured, recreational vehicles or tiny homes, so a backyard cottage or carriage house has no pathway in any district, including the town's 53 planned developments. A codifier footnote on that subsection records that on May 5, 2025 the Town Council adopted Ordinance No. 1.644, Series of 2025, rejecting House Bill 24-1152, Colorado's statewide ADU mandate.

The same one-sentence prohibition covers attached, internal and basement ADUs: it applies in 'all districts' and the definition reaches units 'added to, created within, or detached from' a single-family detached dwelling. Parker's substitute is a 'Secondary Family Space,' defined in Title 11 as 'a secondary Dwelling Unit located in the basement of a single-family, detached dwelling whose occupants and the occupants of the principal dwelling unit live together as a single-household unit and which is neither rented nor locked off from the principal dwelling unit. This is not an accessory dwelling unit.' Table 13.05.A permits one Secondary Family Space as an accessory use by right (A+) in the SF1 (large-lot), SF2 (standard-lot), SF3 (small-lot) and AG (agricultural) districts, subject to Section 11.02.050. It is a family-occupancy arrangement, not a separate rentable apartment: it must be in the basement, must stay unlocked from the main home, cannot be rented, and its occupants must be related to the household by blood or marriage. Ordinance No. 1.644 states the town had administratively approved 55 Secondary Family Space applications over the prior ten years.

The 40 percent cap sits in the building code, not the zoning code: Section 11.02.050 amends the International Residential Code to add Section R302.3.2 (renumbered R302.3.7 by Ordinance No. 4.91.9, adopted June 15, 2026), whose items 1 and 2 read 'No more than one (1) Secondary Family Space is allowed within a single-family, detached dwelling' and 'The Secondary Family Space cannot be larger than 40% of the main dwelling unit, including the basement, based on the original square footage of the single-family, detached dwelling, when initially constructed.' Because the cap is pinned to the home's as-built square footage, later additions do not enlarge the allowance. For scale: if Parker complied with state law, C.R.S. 29-35-402(18)(b) would make any rule that 'does not allow for accessory dwelling unit sizes between five hundred and seven hundred fifty square feet' an unlawful restrictive dimension standard.

No ADU is allowed at all, so there is no ADU occupancy rule; the requirement below governs Parker's only accessory living pathway. Before the Building Division will issue a permit for a Secondary Family Space, the owner must sign a notarized declaration of restrictions, recorded with the Douglas County Clerk and Recorder and binding on later owners, providing that the space 'shall be in effect only so long as either the principle residence, or the Secondary Family Space located within the principal residence, is occupied by the owner of record as their principal residence.' The same declaration requires that occupants of the principal residence and of the Secondary Family Space 'shall be related by blood or marriage,' that interior access between the two remain without any locking device, and that improvements be removed if the covenant is violated. This is exactly the kind of mandate state law forbids: C.R.S. 29-35-403(2)(b) bars a subject jurisdiction from requiring an ADU or any other dwelling on the same lot to be owner-occupied, but Parker has rejected that statute.

Read from Table 13.08.F, Off-Street Parking Requirements, in Section 13.08.080. Short-Term Rental is likewise listed as N/A, corroborating that it too is a prohibited use. Parking is one of the two grounds Parker cited for claiming compliance is impossible: Ordinance No. 1.644 Section 7 declares that because the town is not a transit-oriented community and has no transit service in its single-family neighborhoods, House Bill 24-1152's limits on requiring new ADU parking would 'severely impact the availability of parking.' Under C.R.S. 29-35-403(2)(a) and (3)(a) to (3)(b), a complying jurisdiction generally could only designate an existing off-street space, and could require one new space only where a parcel has no existing off-street parking, sat in a district that required parking for the primary dwelling as of January 1, 2024, and is on a block where on-street parking is banned.

There is no ADU approval pathway of any kind, so none of the permitted, conditional-use or varies categories applies. Table 13.05.A shows 'Dwelling Unit, Accessory' as 'Not permitted' across every district; Section 13.05.020(a)(3) states that 'A blank cell indicates that the use is prohibited in the respective zoning district'; and Section 13.05.020(b) adds that 'All other uses not specifically listed are prohibited unless the Planning Director has determined an appropriate use type for the unlisted use.' The only adjacent permit is an administrative building permit from the Parker Building Division for a basement Secondary Family Space, which Table 13.05.A treats as an accessory use by right (A+) in SF1, SF2, SF3 and AG and which issues once the recorded declaration of restrictions is in hand; no Planning Commission or Town Council hearing is involved. Had Parker complied with C.R.S. 29-35-403(1), an ADU application would have had to be decided through an administrative approval process against objective standards only, with no public hearing.

Section 13.02.020 defines a short-term rental as 'any dwelling, dwelling unit, or portion of any dwelling unit rented or leased for valuable consideration to a person or persons for periods of time less than thirty (30) days,' and Section 13.05.050(d)(6)a.1 lists short-term rentals among the uses 'not permitted as home occupations.' Table 13.08.F also marks Short-Term Rental as 'N/A (Prohibited Use in Zoning District).' Nothing resembling a short-term rental program appears in Title 5, Licenses, Permits and Business Regulations, and site searches of parkerco.gov for 'short-term rental' returned only mobile-business permits. State law leaves this alone in any case: C.R.S. 29-35-403(3)(g) preserves a local government's power to enact or apply a local law concerning the short-term rental of an ADU or any other dwelling on the same lot.