Accessory Dwelling Units

On July 11, 2022, City Council approved Ordinance 1744 allowing Accessory Dwelling Units (ADUs) in Wheat Ridge. The ordinance became effective on August 15, 2022.  This page explains the "what" and "why" of ADUs, summarizes ADU regulations, and provides resources for property owners seeking to legalize or create ADUs.   Types of ADUs - Attached and Detached - Photo Credit: City and County of Denver Opens in new window

ADU Permits and Guides

These resources apply to all types of ADUs:

For new ADUs, use these resources:

For existing dwellings which may qualify as ADUs, use the resources below. Prior to August 15, 2022, ADUs were not permitted by Wheat Ridge City Code. It is understood, however, that ADUs may exist in the community for one reason or another. Owners of property currently containing structures or portions of structures which may fall within the definition of ADU are granted the right to apply to the City for approval of an ADU. There is a two-year grace period to submit an application; applications must be submitted by August 15, 2024, after which time there may be reduced flexibility and/or penalties. Some existing units may be approved as-is, some may require modifications to comply with life safety codes, and some may not be able to legalized as independent dwelling units at all. For those existing ADUs which do not comply with the owner occupancy requirement, there may be an ability to temporarily waive the requirement, but only if applications are received by August 15, 2024.

What are ADUs?

An Accessory Dwelling Unit (ADU) is a smaller, independent residential dwelling unit located on the same property as a detached single-unit home. ADUs can be converted portions of existing homes or additions to new or existing homes (attached ADUs), or they can be new or converted stand-alone accessory structures (detached ADUs). These different types are shown in the image.

ADUs go by many names and are sometimes called granny flats, mother-in-law suites, casitas, or carriage houses. As an independent dwelling unit, an ADU has its own living, sleeping, cooking, and bathroom facilities and is separate from the primary dwelling unit. As an accessory dwelling unit, an ADU cannot be sold separately from the primary house on the property, and in Wheat Ridge, the property owner is required to live in either the primary or accessory unit.

What is allowed in Wheat Ridge?

Key features of the ADU ordinance include the following:

  • ADUs are allowed in all residential, agricultural, and mixed-use neighborhood zone districts as an accessory use to a single-unit home. (They are not permitted on duplex or multi-unit properties.)
  • The property owner must occupy the main house or the ADU.
  • Detached and attached ADUs are allowed.
  • The size of an ADU cannot exceed 1,000 square feet or 50% of the gross floor area (total interior square footage including attached garage) of the main house, whichever is more restrictive.
  • Detached ADUs cannot exceed 25 feet in height (this would accommodate an ADU over a garage). Attached ADUs must comply with the height requirements of main house.
  • ADUs must comply with bulk plane regulations (for properties in residential zones) and setbacks.
  • ADUs cannot be subdivided or sold separately from the main house.
  • ADUs cannot be used as “whole home” short term rentals (STRs) but can be used as “partial home” STRs because the property owner is required to live onsite. An STR license is required to operate a partial home STR in an ADU.
  • Owners of existing dwellings which may qualify as ADUs (including legally nonconforming and unsanctioned) will have two years to apply for legal ADU status. Zoning requirements will not have to be met for existing structures, but building code requirements may apply in order to address life safety concerns, electrical upgrades, and fire separation.
  • Fire code: All sides of an ADU must be within 150 feet of an approved fire access road or fire sprinklers may be required. For attached ADUs, fire separation (such as a fire-rated wall) is required between the ADU and the primary dwelling unit. 

Why allow ADUs? 

Allowing ADUs in Wheat Ridge has been informed by public feedback, City Council direction, and best practices learned from other peer communities and around the country. This adoption culminates a 6-year community conversation on the topic which has included:

  • Two community wide workshops in early 2016,
  • Neighbor-to-neighbor and community-wide discussions during the 2018/2019 Neighborhood Revitalization Strategy process,
  • Discussions through the Let’s Talk resident engagement program that launched in the Fall of 2020, and
  • Feedback from responses to the two editions of the city-wide Resident Survey.

After extensive conversations in study sessions and public meetings in 2015-2016, the 2019 NRS recommended a two-year waiting period. That time has elapsed, and the Let’s Talk program and resident surveys show support for ADU legislation. 

Wheat Ridge was one of the last among peer communities to allow ADUs. Communities nearby and nationwide have continued to adopt and refine ADU ordinances. ADUs are allowed in Arvada, Aurora, Broomfield, Boulder, Denver, Englewood, Golden, Jefferson County, and Lakewood among others. ADUs have not proliferated even in communities where they have been allowed for decades, but their lessons learned have all helped to inform the Wheat Ridge ordinance.

Allowing ADUs can address many of the challenges that exist in Wheat Ridge. ADUs allow adult children to live independently at home, allow aging parents to live in multigenerational households, allow seniors to age in place, and provide an affordable housing option. ADUs are not exclusively used to house seniors but are often an attractive option because a senior homeowner can downsize into an ADU but remain on their property; a senior homeowner can afford to remain in their home by supplementing their income through rental of an ADU; and families can house aging parents in an ADU providing support, proximity, and independence. For these reasons, the American Association of Retired Persons (AARP) is a well-established advocate for ADUs and provides model ordinances and resources for those interested in creating an ADU.

The approved ordinance was crafted with and by City Council with specific consideration for unique Wheat Ridge considerations, including a desire to allow existing and nonconforming ADUs. City Council discussed ADUs extensively at study sessions on November 15, 2021 (packet and video) and April 18, 2022 (packet and video) where there was unanimous consensus to proceed with the ordinance. The ordinance was approved by City Council by a vote of 7 to 1 after a public hearing on July 11, 2022 (packet and video).