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Accessory Dwelling Units

Colorado’s Accessory Dwelling Unit Toolkit is now live!

The ADU Toolkit is a comprehensive resource designed to help local governments support ADUs in their community. The toolkit includes case studies and best practices from around Colorado, lessons learned, strategy guides, and templates for informational handouts and community engagement. 

ADU Toolkit

Overview of HB24 -1152 (C.R.S. 29-35-401 through 405)

Please note: Capitalized terms are used to denote defined terms in the ADU law and may be listed in the Key Terms section below.

Generally, by June 30, 2025, Subject Jurisdictions must allow one Accessory Dwelling Unit (ADU) where Single-Unit Detached Dwellings are allowed in addition to other requirements and standards. Please reference C.R.S. 29-35-402 through 405 and the below sections and linked documents for additional specifics and details.

Executive Order D 2025 005 directs the Department of Local Affairs (DOLA) to summarize the framework, criteria, and benchmarks established in HB24-1152, among other laws, for identifying certified Strategic Growth Compliant Local Governments for the purpose of establishing priority for certain state funding opportunities as specified in Executive Order D 2025 011. If your jurisdiction is subject to HB24-1152, please review the Compliance Framework and Guidelines for Executive Order D 2025 005.

The guidance in the sections that follow is not a substitute for a close reading of the law itself. The law contains some exceptions to its basic requirements, and addresses additional issues not covered in this summary. The following does not constitute legal advice, and local governments are encouraged to consult with their municipal or county attorney for that purpose.

Legislation (HB 24-1152) implementation work is ongoing. Please check back regularly for updates.

Key Dates

  • June 30, 2025: One-time compliance report due to DOLA for Subject Jurisdictions.
  • August 1, 2025: Launch Accessory Dwelling Unit Grant Program.
    • Round 1 closes October 3, 2025.
  • August 13, 2025: ADU Compliance Report Extension requests granted.
  • September 26, 2025: DOLA approves, or requests resubmission of submitted compliance reports.
  • December 30, 2025: If extension request was approved, deadline for filing a compliance report.
  • January 23, 2026: Deadline for resubmitting compliance reports for Subject Jurisdictions who received comments on September 26, 2025.
  • April 24, 2026: Deadline for DOLA to complete second review of ADU compliance reports.
  • No deadline for those seeking certification as an ADU-supportive jurisdiction.

Key dates will also be communicated in any official determination letters sent via the portal in response to submissions.

Featured Image Credit: West Denver Renaissance Collaborative 
Illustration Credit: American Planning Association

Summarized from C.R.S. 29-35-403(1)

By June 30, 2025, a Subject Jurisdiction must allow one ADU as an Accessory Use to a Single-unit Detached Dwelling in any area, lot, or parcel where the jurisdiction allows Single-unit Detached Dwellings. The ADU must be allowed to be either internal to, attached to, or detached from the Single-unit Detached Dwelling.

Applications for ADUs must be reviewed through an Administrative Approval Process that does not include a public hearing. Approval or denial must be based on compliance with Objective Standards included in the land use code or other ADU regulations. The land use code and/or architectural design standards may not include Restrictive Design or Dimension Standards. These requirements apply to all lots that allow the construction of Single-Unit Detached Dwellings regardless of whether the lot or parcel is located in a standard zone district, overlay zone district, or a Planned Unit Development, and regardless of whether restrictive declarations, bylaws, or rules of an HOA prevent ADUs.

Summarized from C.R.S. 29-35-403(2), 29-35-403(3), 29-35-402(18)

Subject Jurisdictions may not restrict ADUs in some ways, but are still allowed to regulate ADUs in a number of other ways, as summarized in the table below. More detail is available in the text of the law and in the below sections of this webpage.

*These requirements do not apply to Exempt Parcels as defined in the law. A Subject Jurisdiction may opt to formalize the allowances for Exempt Parcels in its code.

Subject Jurisdictions MaySubject Jurisdictions May Not
Require the designation of an existing parking space on the lot for the use of the ADU. See the discussion on parking requirements below.

Require the designation of an existing parking space on the lot for the use of the ADU. See the discussion on parking requirements below.
Require the construction of an additional parking space for the ADU, with limited exceptions. See the discussion on parking requirements below.

 

Regulate the Short-Term Rental of ADUs.Require that the ADU or the primary Single-Unit Detached Dwelling on the lot remain owner-occupied, with limited exceptions. See the discussion on owner-occupancy restrictions below.
Require compliance with design and dimensional standards not included in the definition of a Restrictive Design or Dimension Standard.Require compliance with architectural style, building material, or landscaping standards that are more restrictive than those that apply to the single-unit home on the lot.
Limit the maximum size of an ADU to be no larger than the size of the Single-Unit Detached Dwelling on the lot.Require a larger lot for the ADU than would otherwise apply for a Single-Unit Detached Dwelling on the lot.
Allow ADUs smaller than 500 square feet, or larger than 750 square feet. Require larger side or rear setbacks than those stated in the law. See the discussion on setbacks below.
Allow the construction or conversion of more than one ADU per lot where a Single-Unit Detached Dwelling is allowed.Apply more restrictive design or dimensional standards to factory-built ADUs than stick-built ADUs.
Define ADUs to include or exclude specific types of housing, such as motor homes, recreational vehicles, or multi-purpose trailers.Define ADUs in such a way that excludes a type of ADU in the law’s definition, such as internal, attached, or detached ADUs.
Apply historic district standards to ADUs located in historic districts.Disallow ADUs that are between 500 and 750 square feet in size.
Require compliance with adopted fire, building, utility, or stormwater codes. 
Require proof of water supply or wastewater treatment capacity as a condition of ADU approval. 
Require the payment of generally applicable development impact fees. 
Require the mitigation of development impacts as permitted by the Colorado Regulatory Impairment of Property Rights Act, C.R.S. 29-20 Part 2. 
Use local programs to encourage the construction of ADUs, or the conversion of Single-Unit Detached Dwellings to include ADUs, with income restrictions to increase the supply of affordable housing. 

Please note: Capitalized terms are used to denote defined terms in the ADU law and may be listed in the Key Terms section below.

Subject Jurisdictions may comply with the requirements of C.R.S. §§ 29-35-402, 29-35-403 by revising local zoning and land use codes, regulations, and/or policies that are relevant to this law. DOLA provides a number of tools to help local governments update their land use and zoning codes which may be found in the Tools & Resources section below. 

Local governments should also review DOLA’s Template Land Development Code. This modernized code is representative of current best practices and it supports compliance with the 2024 land use and housing laws.

Jurisdictions who are reviewing/revising current zoning and land development regulations for alignment with the requirements of C.R.S. §§ 29-35-402, 29-35-403 should focus on the following:

The definition of an Accessory Dwelling Unit (ADU)

Summarized from C.R.S. 29-35-402(2)

While the law includes a definition of Accessory Dwelling Unit, it does not require that jurisdictions adopt that exact definition. It gives jurisdictions the right to exclude motor homes, recreational vehicles, and other specific types of housing from the definition, or to include them. However, the jurisdiction’s definition of ADU may not result in restricting or prohibiting ADUs that would be permitted under the law’s definition such as an attached or internal ADU, or an ADU that is a detached structure.

The list(s) or table(s) of allowed uses in each zone district

Summarized from C.R.S. 29-35-403(1)

In general, ADUs should be listed (or included in a table) as an allowed or accessory use in every zone district where Single-Unit Detached Dwellings are an allowed use (including PUDs). In zone districts where Single-Unit Detached Dwellings are a conditional or special use, ADUs must be allowed as an accessory use to an existing Single-Unit Detached Dwelling. Instead of including this information in a table, jurisdictions may include language in their development codes clearly indicating that ADUs are allowed in conjunction with all Single-Unit Detached Dwellings in their jurisdiction. This applies regardless of whether Local Law uses a different zoning or regulatory term for a freestanding house on a single lot designed for occupancy by a single household. 

NOTE: This guidance generally uses the term 'allowed' in conformance with the law, but jurisdictions may use 'permitted' or any other similar terms that clearly indicate an ADU may be constructed.

The procedures for approval of an ADU

Summarized from C.R.S. 29-35-402(5a), 29-35-402(17), and 103(1)

An Administrative Approval Process is required for the review of an ADU. Zoning and land development regulations should be reviewed to ensure that applications for ADUs are subject only to an Administrative Approval Process using Objective Standards, and to remove any requirements for a public hearing before approving an ADU. If the Local Laws allow an administrative decision to be "elevated," "sent up," "referred," or "called up" to an appointed or elected body for review and decision, those provisions should be modified to exclude ADUs from potential public hearing requirements. 

There is one exception: If the ADU is located in a locally designated historic district, and the Subject Jurisdiction has been designated by History Colorado as a Certified Local Government, the application can be subject to the public hearing requirements applicable to other historic district properties. The standards applied in this process must be locally adopted historic regulations or the Secretary of State’s historic preservation standards.

An appeal of an administrative decision to a Board of Adjustment or Planning Commission, for example, is allowable under the law's definition of Administrative Approval Process. The appeal should be limited to a review of the project in relation to the Objective Standards that governed the administrative decision, rather than any subjective determination outside of those Objective Standards.

The standards, conditions, and criteria for approval of ADUs

Summarized from C.R.S. 29-35-402(17)

The standards, conditions, and criteria applied for the review of an ADU shall be objective meeting the law’s definition of “Objective Standards.” Standards and conditions applicable to ADUs will require careful review to meet the requirements of C.R.S. §§ 29-35-402, 29-35-403. They must be "Objective," which means standards using a defined benchmark or criterion that allows for decisions to be made consistently regardless of who makes the decision. 

These standards cannot require subjective determinations of whether the application is consistent with adopted plans (including comprehensive or development plans); compatible with the land use or development of the surrounding area; or consistent with public welfare, community character, or neighborhood character.  Although not listed in C.R.S. § 29-35-402, decision criteria such as "compatible", "harmonious", "attractive", "similar", and "contributing" are generally considered subjective standards. 

The requirement for Objective Standards applies regardless of whether they appear as "use-specific standards" or "performance standards" applicable to the ADU use in particular, or as decision criteria that staff must use in determining whether to issue a specific type of permit or decision.

Parking regulations

Summarized from C.R.S. 29-35-403(2a), (3a), and (3b)

The law prohibits Local Laws from requiring that a new parking space be constructed or available for each ADU, but does provide exceptions: 

  1. The jurisdiction may require the designation of an existing parking space on the lot for the use of the ADU, if such a parking space already exists at the time the ADU is constructed or converted; or
  2. The jurisdiction may require the construction of a new off-street parking space if:
    1. The ADU is in a zone district that, as of January 1, 2024, required one or more off-street parking spaces for a Single-Unit Detached Dwelling; and
    2. There is no existing parking space on the lot (including a driveway, garage, or tandem parking space) that could be used for the ADU; and
    3. The ADU is located on a block where the jurisdiction prohibits on-street parking.

To use the second exception listed above, all three conditions must be present and codified. Additionally, jurisdictions should be aware of whether their residential parking requirements are “per dwelling unit,” and whether an ADU would be considered a dwelling unit when applying the parking requirement.

Examples:

“Parking for an accessory dwelling unit shall comply with C.R.S. §§ 29-35-403(3)(a) and (b):

  1. No parking space(s) shall be required so long as there is an existing parking space available for designation, including a driveway, garage, tandem parking, other off-street parking space, or on-street parking is available.
  2. Where on-street parking is prohibited, on-site parking is unavailable, and parking is required as of January 1, 2024 for the primary dwelling unit, at least one (1) parking space shall be provided.”

“Accessory Dwelling Units.

  1. Standards
    1. Parking requirements. Off street parking is not required.”

“Parking. An accessory dwelling unit shall not provide more than two off street parking spaces and is not required to provide any off-street parking.”

“Off-street parking specific to an ADU is not required unless all 3 of the following conditions apply, in which case one off-street parking space shall be provided on the lot [if]: 

  1. there is no existing off-street parking space on the lot,
  2. the lot is located in a zone district that requires one or more parking spaces for the principal building, and
  3. the lot is located on a block where on-street parking is prohibited.”

ADU square footage, setbacks, and minimum lot size regulations

Summarized from C.R.S. 29-35-402(18b), 402(18c), 403(d), and 403(3c)

Minimum Square Footage: 

C.R.S. § 29-35-402 contains language that establishes a minimum right to ADUs that are between 500 and 750 square feet (sq ft) in size. Jurisdictions may choose to allow ADUs smaller than 500 feet or larger than 750 feet. Jurisdictions may also require ADUs be no larger than the Single-Unit Detached Dwelling on the lot. 

Example: 

A jurisdiction adopts a development regulation stating ADUs can be no larger than 50% of the floor area of the primary dwelling unit. Under this regulation, a property with a house that is 800 sq ft would be limited to 400 sq ft ADU which is below the 750 square feet that jurisdictions are required to allow. 

To comply with state law, the local code must also say something like, "the square footage of an ADU shall not exceed fifty (50) percent of the square footage of the principal structure. Except where the principal structure is less than one thousand, five hundred (1,500) square feet, the ADU shall not exceed seven hundred and fifty (750) square feet, but in no case shall exceed the square footage of the principal structure."

Side and Rear Setbacks: 

C.R.S. § 29-35-402 states minimum side setbacks may not be larger than those that apply to the Single-Unit Detached Dwelling on the lot regardless of ADU type (attached, integrated, or detached).

Minimum rear setbacks may not be larger than those that apply to accessory building types in the same zone, or five feet, whichever is greater, also regardless of ADU type (attached, integrated, or detached).

Minimum rear setbacks for attached ADUs may not be larger than those that apply to other accessory building types in the same zone or five feet, whichever is greater. DOLA interprets this to mean that if the ADU is an addition to the primary structure, the minimum rear setback for the ADU would need to be no more than 5 feet or the equivalent setback for accessory buildings in that district, if it's greater. However, if the ADU is not located in that addition (for example if the applicant added a family room to the rear while converting a previous basement family room into an ADU), then the minimum would be the same as the primary unit since the ADU is within the original footprint of the primary dwelling.

Examples:

“ADUs are subject to the principal building front and side setback requirements in the underlying zone district. ADUs are subject to the rear setback requirement for accessory buildings. If the ADU is attached or internal to the principal building, the portion of the structure containing the principal dwelling unit must maintain the rear setback for principal buildings.”

“Accessory dwelling units may be located in the required rear yard provided that not more than sixty (60) percent of the required rear yard is covered. Accessory dwelling units may observe a minimum five-foot setback from the rear lot line with the following conditions:

  1. Five-foot rear yard setbacks shall receive approval from the Electrical Superintendent and Public Works Director for overhead and underground utility clearance; and
  2. Roof eaves or other incidental architectural features may not encroach into the five-foot setback.
  3. Administrative adjustments to reduce the setback further are not allowed.”

“Minimum rear setbacks for an ADU shall not exceed the lesser of: 

  • the minimum rear setback for other accessory building types in the same zone district, or
  • five feet (5').”

“The minimum rear yard setback for principal buildings does not apply to a principal building with an attached accessory dwelling unit provided the following standards are met:

  1. Any floor area of the building located within the area of the minimum rear yard setback is solely floor area of the accessory dwelling unit;
  2. The attached accessory dwelling unit portion of the building has a rear yard setback of five feet or more;
  3. The maximum building coverage of the attached accessory dwelling unit portion of the building and any accessory buildings or structures within the area of the minimum rear yard setback is 500 square feet; and
  4. The maximum height of any portion of the building located within the area of the minimum rear yard setback is 20 feet. The height of this portion of the building shall be measured to the uppermost point of the portion of the building with the accessory dwelling unit.

Sample ADU Setback and Height Diagram

Image Credit: City of Boulder

Minimum Lot Size: 

C.R.S. § 29-35-402, the definition of "Restrictive Design or Dimension Standard” prohibits a more restrictive minimum lot size for an ADU than for a single-unit detached dwelling in the same zoning district. This means a jurisdiction cannot require more lot area for an ADU than what is already required for the single-unit detached dwelling in that zoning district. Jurisdictions should be aware of whether the zone districts require minimum lot area “per dwelling unit,” and whether an ADU would be considered a dwelling unit when applying a minimum lot size standard.

Owner occupancy on lots with ADUs

Summarized from C.R.S 29-35-403(2b)

The law prohibits Local Laws from requiring that the Single-Unit Detached Dwelling or the ADU be occupied by the owner of the lot. The law provides two exceptions: 

  1. Local Law can require evidence that the owner resides on the lot at the time an application for construction or conversion of an ADU is filed (but this exception does not apply if the ADU and new Single-Unit Detached Dwelling are being constructed at the same time).
  2. Local Law may require evidence that the owner resides on the lot at the time an application for a license or permit allowing short-term rental of the ADU is filed.

Regarding owner occupancy requirements of short-term rentals in ADUs; DOLA has interpreted the law to mean that while the law prohibits tying ADU development or general use for long-term occupancy to owner occupancy, it does still allow jurisdictions to impose owner occupancy requirements specifically related to short-term rental activity. While the statute only allows enforcing owner occupancy at the time of getting a short-term license or permit, for many jurisdictions there is regular relicensing to continue operating a short-term rental. 

Example:

“Occupancy. The property owner shall reside on the property on the date an application is filed to construct an ADY; provided, however, this requirement does not apply to the construction of an ADU on a vacant lot.”

“Either the principal building or the ADU must be occupied by the owner of the property on which the principal building and ADU are located, when a home-based business license application for the short-term rental of either structure (or portions thereof), is submitted to the Town.”

“A maximum of one short-term rental license may be issued, pursuant to the home-based business regulations, for any property with an accessory dwelling unit for either the accessory dwelling unit or the single-family dwelling unit but not both, as long as the property owner occupies one of these units. Short-term rentals are not permitted unless the property owner occupies one dwelling unit on the property. A maximum of two long-term residential rental licenses (lease terms greater than 30 days) maybe issued to a property owner for the rental of an accessory dwelling unit and single-family dwelling unit, with a separate business license required for each rental.”

Planned Unit Developments (PUDs)

Summarized from C.R.S. 24-67-105(5.3)

Two separate provisions of the law address its impact on Planned Unit Developments, or other similar regulatory tools (such as Planned Development Overlays): The first applies to existing PUDs and the second to future PUDs.

The law applies to areas of approved Planned Unit Developments that allow the construction of Single-Unit Detached Dwellings to the same extent it applies to other properties in non-PUD developments. Meaning, in areas where Single-Unit Detached Dwellings are allowed, ADUs must be allowed as an accessory use to a Single-Unit Detached Dwelling regardless of whether the PUD is silent on ADUs and/or accessory uses, or prohibits ADUs. The approval, permitting, and construction of an ADU in a PUD development shall also only be subject to an Administrative Approval Process subject to only Objective Standards.

The law also provides that future PUDs may not contain provisions that restrict the construction or conversion of ADUs in ways not permitted by the law.

Jurisdictions should consider incorporating language within the portion of their land use and development codes that grants the authority to create PUD zone districts or the portion that regulates ADUs.

Examples:

“Prior Approvals: Any prohibition of accessory dwelling units in any prior planned development, planned residential development, planned unit development, site review, or use review approval is void and shall not be enforced, provided the accessory dwelling unit is established consistent with the requirements of this subsection.

Review Process: The establishment of an accessory dwelling unit on a property subject to a planned development, planned residential development, planned unit development, or site review shall be reviewed and approved under the minor modification process and shall be deemed to not alter the basic intent of the site plan approval, provided the proposal meets the remaining minor modification standards.”

“New and existing planned developments and planned unit developments that allow the construction of one or more single-unit detached dwellings shall not restrict ADUs more than this code restricts ADUs outside of a planned development or planned unit development or in any way that is prohibited by C.R.S. 29-35-403 as amended.”

“Eligible Zone Districts: An accessory dwelling unit (ADU) shall be permitted as an accessory use to single-family detached dwellings in all zones.

  1. Planned Unit Developments Included: Accessory dwelling units shall also be permitted in any Planned Development Districts (PD’s) on lots that allow single-family detached dwellings.”

“Accessory Dwelling Units are allowed in all residential zone districts and in any area within a Planned Development District Designated for Single-Family Residential Uses upon administrative review by the Director and approval of a building permit.”

“Accessory dwelling units are a permitted use on all lots that allow a single-unit or two-unit dwelling, including without limitation properties that are zoned Planned Development.”

“Planned Development Zone District (PDZ) - Establishment of the Land Use Types, Mix, and Intensity of Land Uses:

  1. Each PDZ district shall state whether integrated, attached, and detached ADUs are permitted.
  2. Except where a Land Use Plan or Development Plan associated with PDZ states otherwise:
    1. In portions of PDZs containing residential or a mix of residential and nonresidential uses, Home Occupation, Accessory uses shall be allowed as accessory to all primary residential uses.
    2. In portions of PDZs containing residential or a mix of residential and nonresidential uses, structures allowed as accessory to a residential use in the R-1 6 zone district shall be allowed as accessory to all primary residential uses.

A Subject Jurisdiction should consult with their city attorney to determine the appropriate language.

A subject jurisdiction is any jurisdiction that is required by C.R.S. 28-35-402 to allow an Accessory Dwelling Unit (ADU) where Single-Unit Detached Dwellings are allowed and to meet any other requirements of C.R.S. 29-35-403. Jurisdictions that are subject to C.R.S. 29-35-403 are listed in the Subject Jurisdiction section of this page.

An ADU Supportive Jurisdiction (C.R.S. 29-25-404) is a jurisdiction that has been certified by DOLA as a result of adopting one or more ADU supportive strategies (C.R.S. 29-35-404) as well as complying with the requirements of HB24-1152. If a jurisdiction wishes to become an ADU Supportive Jurisdiction and is not already a Subject Jurisdiction, it must voluntarily meet the requirements detailed in C.R.S. 29-35-403. Becoming certified as an ADU Supportive Jurisdiction is a voluntary process and can be pursued by any jurisdiction, whether or not it is a Subject Jurisdiction. 

Once obtained, the ADU Supportive Jurisdiction Certification allows the jurisdiction to apply for DOLA’s ADU Grant Program, and allows residents of that jurisdiction to apply for ADU construction financing from Colorado Housing and Finance Authority (CHFA).

Summarized from C.R.S. 29-35-402(21)

The law applies to Subject Jurisdictions, which include:

  • Colorado Home Rule or statutory cities and towns, Territorial Charter cities and towns, and consolidated cities and counties, that are within a Metropolitan Planning Organization and have a population of 1,000 or more as reported by the State Demography Office; and
  • Those portions of Colorado counties, including Home Rule counties, that are within a Metropolitan Planning Organization and within a Census Designated Place with a population of 40,000 or more as reported in the most recent federal decennial Census.
  • However, any jurisdiction may voluntarily comply with HB24-1152 to become eligible for the  ADU Fee Reduction and Encouragement grant program. Additional information is within the Certification Process section below.

The following is a list of HB24-1152 Subject Jurisdictions. Please refer to DOLA’s Multilaw Applicability interactive map and spreadsheet to see where State Land Use and Housing laws apply.

  • Arvada
  • Aurora
  • Bennett
  • Berthoud
  • Boulder
  • Brighton
  • Broomfield
  • Castle Pines
  • Castle Rock
  • Centennial
  • Cherry Hills Village
  • Colorado Springs
  • Columbine Valley
  • Commerce City
  • Dacono
  • Denver
  • Eaton
  • Edgewater
  • Englewood
  • Erie
  • Evans
  • Federal Heights
  • Firestone
  • Fort Collins
  • Fort Lupton
  • Fountain
  • Frederick
  • Fruita
  • Glendale
  • Golden
  • Grand Junction
  • Greeley
  • Greenwood Village
  • Hudson
  • Johnstown
  • Kersey
  • Lafayette
  • Lakewood
  • La Salle
  • Littleton
  • Lochbuie
  • Lone Tree
  • Longmont
  • Louisville
  • Loveland
  • Lyons
  • Manitou Springs
  • Mead
  • Milliken
  • Monument
  • Nederland
  • Northglenn
  • Palisade
  • Palmer Lake
  • Parker
  • Platteville
  • Pueblo
  • Severance
  • Sheridan
  • Superior
  • Thornton
  • Timnath
  • Westminster
  • Wheat Ridge
  • Windsor
  • Woodland Park
  • Highlands Ranch (Unincorporated Douglas County)

Summarized from C.R.S. 29-35-404(1a), (2), and (3)

HB24-1152 contains provisions allowing Colorado communities to seek designation as an ADU Supportive Jurisdiction, whether or not they are a Subject Jurisdiction required to comply with the law.

In order to achieve this designation, Colorado communities must comply with the requirements of the law, and also implement at least one of 10 supportive strategies to promote the construction, conversion, or use of ADUs. While nine of those strategies are defined in the law, the tenth is an option allowing for any additional strategy suggested by the community and approved by DOLA to achieve those goals. 

These strategies are listed and described in a document within the Tools & Resources section below. This document also contains examples in and outside of Colorado, and discussion on the pros and potential cons with each strategy. Implementation of at least one of those 10 strategies must also be documented in the report.

Designation as an ADU Supportive Jurisdiction is documented by a certificate issued by DOLA, which makes the Subject Jurisdiction, or voluntary community, eligible to apply for grants under a new Accessory Dwelling Unit Fee Reduction and Encouragement Grant Program. Subject Jurisdictions are encouraged to take the additional step necessary to achieve this designation, as the state may in the future make additional resources and assistance available to ADU Supportive Jurisdictions.

The application to be certified as an ADU Supportive Jurisdiction may be filed using the Land Use and Housing Implementation Portal.

For Subject Jurisdictions: No later than June 30, 2025, every Subject Jurisdiction must file a compliance report with DOLA demonstrating that the community has complied with the requirements of the law. Or, request an extension of up to six months if the Subject Jurisdiction demonstrates that it has: 

  • Initiated the process of compliance,
  • A timeline for completion of that process, and
  • Explained the reason for not meeting the initial compliance deadline.

For nonsubject jurisdictions that are seeking Supportive Jurisdiction certification: A compliance report is required, but there is not a deadline. 

The compliance report, extension request, and application to be certified as an ADU Supportive Jurisdiction may be filed using the Land Use and Housing Implementation Portal.

Summarized from C.R.S. 38-33.3-106.5(4)

Three provisions of the law address restrictive covenants that may apply to neighborhoods with Single-Unit Detached Dwellings.

In Subject Jurisdictions, HOA covenants adopted on or before June 30, 2025 may not be applied to restrict the creation of an ADU in any way that is prohibited by the law. Similarly, restrictive covenants created after June 30, 2025, may not contain provisions that restrict the creation of an ADU in ways that are prohibited by the law. As a practical matter, these provisions mean that the courts of Colorado will not be available to enforce restrictive covenants that violate these requirements.

A third provision allows HOAs to continue to apply "Reasonable Restrictions" on ADUs. A Reasonable Restriction is defined as "a substantive condition or requirement that does not unreasonably increase the cost to construct, effectively prohibit the construction, or extinguish the ability to otherwise construct an ADU" pursuant to the law. Among other things, an HOA may apply standards and conditions to ADUs if those standards are also applied to the construction of other types of accessory buildings.  They may apply standards and conditions to the creation of an ADU within an existing Single-Unit Detached Dwelling if they would apply the same standards and conditions to other internal modifications of the house.

NOTE: SB24-174, also passed by the General Assembly during its 2024 session, includes a similar provision for Common Interest Ownership Associations (i.e. condominium associations). After June 30, 2024, it prohibits them from adopting new regulations that prohibit or restrict the construction of ADUs if the zoning laws of the local jurisdiction would otherwise allow ADUs.

Summarized from C.R.S. 29-35-402

This section lists several key terms defined in the law. Please note that the law contains numerous additional definitions that may be important in specific contexts.

"Accessory Dwelling Unit" means an internal, attached, or detached dwelling unit that: (a) provides complete independent living facilities for one or more individuals; (b) is located on the same lot as a proposed or existing primary residence; and (c) includes facilities for living, sleeping, eating, cooking, and sanitation.
NOTE: Subject jurisdictions are not required to adopt this definition of an ADU, but the use of a different definition cannot result in more restrictions on ADUs than are permitted by the law. For example, subject jurisdictions’ definitions must include internal, attached, and detached ADUs.

"Administrative Approval Process" means a process in which: (i) a development proposal for a specified project is approved, approved with conditions, or denied by local government administrative staff based solely on its compliance with Objective Standards set forth in local laws; and (ii) does not require, and cannot be elevated to require, a public hearing, a recommendation, or a decision by an elected or appointed public body or a hearing officer.

"Exempt Parcel" means a parcel that is: (a) not served by a domestic water and sewage treatment system, as defined in section 24-65.1-104 (5), or is served by a well with a permit that cannot supply an additional dwelling unit; (b) a historic property that is not within a historic district; or (c) in a floodway or in a one hundred year floodplain, as identified by the federal emergency management agency.

"Local Law" means any code, law, ordinance, policy, regulation, or rule enacted by a local government that governs the development and use of land, including land use codes, zoning codes, and subdivision codes.

"Objective Standard" means a standard that: 

  1. Is a defined benchmark or criterion that allows for determinations of compliance to be consistently decided regardless of the decision maker; and
  2. Does not require a subjective determination concerning a development proposal, including but not limited to whether the application for the development proposal is:
    1. Consistent with master plans, or other development plans;
    2. Compatible with the land use or development of the area surrounding the area described in the application; or
    3. Consistent with public welfare, community character, or neighborhood character.

"Restrictive Design or Dimension Standard" means a standard in a Local Law that: 

  1. Requires an architectural style, building material, or landscaping that is more restrictive for an Accessory Dwelling Unit than for a Single-Unit Detached Dwelling in the same zoning district;
  2. Does not allow for Accessory Dwelling Unit sizes between five hundred and seven hundred fifty square feet;
  3. Requires side setbacks for an Accessory Dwelling Unit that are larger than the side setbacks required for a primary dwelling unit in the same zoning district;
  4. Requires a rear setback for an Accessory Dwelling Unit that is larger than the greater of:
    1. The rear setback required for other accessory building types in the same zoning district; or
    2. Five feet;
  5. Is a more restrictive minimum lot size standard for an Accessory Dwelling Unit than for a Single-Unit Detached Dwelling in the same zoning district; or
  6. Applies more restrictive aesthetic design or dimensional standards to Accessory Dwelling Units that are factory-built residential structures, as defined in section 24-32-3302 (10), than other Accessory Dwelling Units.

"Single-Unit Detached Dwelling" means a detached building with a single dwelling unit on a single lot.

The legislative declaration (C.R.S. 29-35-401) in HB24-1152 highlights that Accessory Dwelling Units (ADUs) provide more housing options for smaller and lower-income households, and elderly individuals who wish to age in their neighborhoods. By allowing the construction of these smaller, more affordable units in areas where utilities and infrastructure are already in place, ADUs present a viable alternative to low-density, dispersed development.

This can help reduce water usage, greenhouse gas emissions, infrastructure costs, and household transportation and energy expenses. Because single-family detached home neighborhoods often occupy a large percentage of land in Colorado communities, allowing ADUs in those areas can serve as an important way to increase housing supply with minimal impacts on their neighborhoods, and can increase attainable and affordable housing options in high opportunity neighborhoods. After requiring that local governments reduce barriers to ADUs, California estimates that ADUs now make up to 20 percent of new housing constructed in that state
 (Accessory Dwelling Units (ADUs) in California | Bipartisan Policy Center). 

Better aligning ADU regulations across many Colorado communities can help achieve economies of scale by reducing the variability of regulations between jurisdictions, thereby enabling more standardized and modular ADU designs, a more robust market of ADU developers, and associated cost reductions.

Grant Program

HB24-1152 established the Accessory Dwelling Unit Grant Program (ADUG) at DOLA and a financing program for homeowners to construct ADUs at the Colorado Housing and Finance Authority (CHFA). The ADU Grant Program will offer support to local governments for activities that promote the construction of accessory dwelling units, such as offsetting costs for developing pre-approved accessory dwelling unit plans, providing technical assistance to homeowners, or waiving, reducing, or providing financial assistance for accessory dwelling unit associated fees and other required costs. This program awards grants to local governments. If you are a resident interested in potential ADU financing, please contact your local CHFA representative

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