ADU rules in Monument

A detached backyard ADU is allowed on any lot in any Monument zone district that permits single-family detached dwellings, and the schedule of uses lists 'Accessory dwelling unit' as an accessory use (A) in all ten standard districts (Large Lot Residential, SFD-1, SFD-2, Residential Attached, Mobile Home Park, Downtown Business, Commercial Center, Business Campus, Light Industrial and Public) and in all seven Regency Park overlay districts. Only one ADU is allowed per lot, and a detached ADU may sit only in the side or rear yard, including a corner yard. Ordinance No. 17-2026, adopted 7-6-2026, added an express statement that the Town shall allow one ADU on a lot in any zoning district that allows single-family detached dwellings and that a new or previously approved PUD or Planned Development permitting single-family detached dwellings may not restrict ADUs more than the standards that apply outside a PUD. A temporary structure, mobile home or recreational vehicle may not be used as an ADU.

An ADU may be created inside the principal building (separated by a wall, door or combination of the two) or built as an addition to the principal building, so basement, upper-floor and bump-out ADUs are all permitted. Attached or integrated ADUs may be located in the front and side, unlike detached ADUs, which are restricted to the side or rear yard. An attached or integrated ADU may not exceed the maximum height permitted for the principal building in the district and may never exceed twenty-five feet. Where the ADU needs a new outside entrance, only one entrance visible from the street frontage is allowed and any additional entrance must go on a side or rear elevation.

Ordinance No. 17-2026, adopted 7-6-2026, rewrote the size cap. The operative rule is that an ADU's floor area may not exceed fifty percent of the principal structure's floor area or seven hundred fifty square feet, whichever is GREATER, and that in the Large Lot Residential District an ADU may exceed 750 sq ft but not 1,250 sq ft. The same amendment added that in no case can an ADU be smaller than 500 sq ft. Height is capped separately: a detached ADU may not exceed sixteen feet unless it is created by converting an existing garage, in which case twenty-five feet applies; an attached or integrated ADU is held to the district maximum for the principal building and to twenty-five feet. Caution: the codified text on Municode still shows the superseded December 2025 rule (600 sq ft or fifty percent of the principal structure, whichever is LESS), because the code is only codified through Ord. No. 12-2026 of 5-4-2026.

Monument requires the property owner to demonstrate that the owner resides on the parcel at the time an application to construct or convert an ADU is submitted. That requirement does not apply when the ADU is being built at the same time as a new primary dwelling. The provision is copied from the narrow carve-out Colorado allows in C.R.S. 29-35-403(2)(b), which otherwise forbids a subject jurisdiction from requiring an ADU, or any other dwelling on the same lot, to be owner-occupied. So there is no continuing owner-occupancy condition: once the ADU is permitted and built, the owner may move away and rent out both units on a long-term basis. Ordinance No. 17-2026 left this subsection unchanged. Separately, the Town's fifty percent use tax rebate for low- and moderate-income ADUs requires the applicant to own and reside on the property when the rebate application is submitted.

Ordinance No. 17-2026, adopted 7-6-2026, replaced Monument's earlier one-space-per-ADU rule with the state-law default: additional parking is not required in conjunction with the construction or conversion of an ADU. One off-street space is required only if all three conditions are met, namely there is no existing off-street parking space on the lot, the lot is on a block where on-street parking is prohibited for any reason, and the lot is in a zone district that requires one or more parking spaces for the principal dwelling. That mirrors C.R.S. 29-35-403(3)(b). Caution: the codified text on Municode still shows the superseded December 2025 rule of one off-street space per attached or detached ADU, waivable by the Director of Planning and satisfiable with shared parking. The code also warns that the Town will not review or enforce private covenants or HOA parking restrictions that could prevent shared parking.

In residential districts an ADU is approved administratively. No ADU may be built, established or occupied without a permit issued by the Director of Planning or designee, and an ADU requires site plan approval under Sec. 18.03.150. The Review Procedures Chart at Sec. 18.01.220, Table 1.1 assigns site plan approval to Administrative Approval (AD) by Town staff, with no Planning Commission, Town Council or Board of Adjustment action and no public hearing, which is what HB24-1152 means by an administrative approval process. An ADU in a non-residential zone district (Downtown Business, Commercial Center, Business Campus, Light Industrial or Public) instead requires a conditional use permit, which under Table 1.1 goes to a Planning Commission public hearing and then Town Council action. There is no ADU-specific application form or checklist published by the Town; applicants use the general Development Review Application and site plan checklist.

Long-term rental of an ADU is permitted: there is no continuing owner-occupancy requirement and the Monument Municipal Code contains no residential rental license or rental cap. Short-term rental is banned. Sec. 18.03.340.D.4.j provides that no ADU, and no other dwelling unit on the same lot as an ADU, may be used for short-term rentals, defining a short-term rental as rental of any dwelling unit for thirty days or less. That means adding an ADU also forecloses short-term renting the main house. Ordinance No. 17-2026 left this subsection unchanged, and C.R.S. 29-35-403(3)(g) expressly preserves local authority over short-term rental of ADUs. The Town has no short-term rental licensing program at all: a search of every section heading in Titles 1 through 18 of the Municipal Code found no short-term rental or vacation rental chapter, only a bed and breakfast inn standard at Sec. 18.04.120 and a general town sales tax on lodging at Sec. 3.09.050.H. Properties used for short-term rentals are also ineligible for the Town's ADU use tax rebate.