ADU Code Update

Share your input about proposed Accessory Dwelling Unit (ADU) code changes to the Broomfield Municipal Code. You can ask questions about the proposed changes below using the “Questions” tab or start a conversation and provide your feedback under the “Forum” tab at the bottom of the page.

Your feedback will be used to help shape the proposed changes to the code to meet the needs of the community.

Project Overview

The proposed Accessory Dwelling Units (ADU) code changes will address direction from Broomfield City Council (see the January 21, 2025 Study Session), recent Colorado legislation, and to make technical edits to the existing code to clarify the use of terms such as “mobile homes” and “tiny homes.”

Broomfield City Council approved an ordinance in 2019 allowing ADUs in any zone district in the city where single-unit dwellings are permitted. ADUs can create smaller and more affordable homes in existing communities. ADUs also help homeowners add value to their property or provide options for intergenerational living arrangements that support child or elder care and aging in place.

Since 2019, the Colorado General Assembly passed legislation to permit ADUs statewide. Broomfield already permits ADU throughout the community. The proposed modifications would more fully align Broomfield’s ADU code with the new state legislation City and County of Broomfield staff have also identified several technical edits that would make the existing code easier to use. Broomfield City Council will review and vote on the proposed changes at public hearings, listed in the Key Dates at the top of this page.

The proposed ADU code changes will address the following elements:

• Changes to some setback requirements for ADUs.
• Changes to parking space requirements for ADUs.
• Changes to some occupancy requirements for ADUs.
• Technical changes, including defining the use of the terms “tiny home” and “tiny house” in Broomfield, and establishing regulations for their use.
• Modifying other terms such as “mobile homes” and “manufactured homes” to clarify the difference between these structures and bring the definitions into line with the state’s definition of these terms.

While the community can provide input on the proposed ADU code changes, suggestions that conflict with state requirements cannot be implemented.

Technical Edits: Tiny Homes, Tiny Houses and Mobile Homes

These proposed edits, unrelated to the new Colorado legislation, clarify the types of structures that can be used as an ADU in Broomfield. Currently, Broomfield’s ADU code:

• Prohibits mobile homes, travel trailers, recreational vehicles, shipping containers, storage containers and other such temporary structures from being used as an ADU and
• Does not incorporate or define the terms “Tiny Houses” and “Tiny Homes.”

Proposed changes to Broomfield’s ADU Code supported by Broomfield City Council:

• Update the definitions used in the code to match the definitions used by the State of Colorado.
• Provide a path to allow Tiny Homes to be used as ADUs in Broomfield.

The code will still prohibit the use of mobile homes, RVs, shipping containers and other such temporary structures for use as an ADU.

New Colorado Legislation: HB24-1152 Accessory Dwelling Units

This bill aims to increase the availability of Accessory Dwelling Units (ADUs) in Colorado to address state housing shortages and housing affordability issues. While Broomfield already allows ADUs in all zone districts where single-unit dwellings are permitted, the new state regulations include several other provisions that Broomfield’s current ADU regulations do not currently include or allow.

“Restrictive” Design

The recent Colorado legislation defines “restrictive” design as being any zoning standard that does any of the following:

• Requires a stricter architectural standard (style, material, or landscaping) that is more restrictive for an ADU than for a single-unit detached dwelling in the same zoning district.
• Requires the size of any ADU to be smaller than 500 square feet, or larger than 750 square feet.
• Requires side setbacks for an ADU that are larger than the side setbacks for a primary dwelling unit in the same zoning district.
• Requires a rear setback for an ADU that is larger than five feet.
• Applies more restrictive aesthetic design or dimensional standards to accessory dwelling units that are factory-built residential structures than other accessory dwelling units.

Impacts to Broomfield’s ADU code:

• The proposed code update will include modifications to certain setback standards in some zone districts to avoid any instances of a “restrictive” setback.
• Broomfield’s code does not otherwise include any standards that would be considered “restrictive” and would need to be changed.

Occupancy Requirements

HB24-1152 prohibits local governments from requiring that an ADU be owner-occupied, with the following exceptions:

• A local jurisdiction may require a property owner to prove they reside on the parcel when an application is submitted:
  • To construct or convert an ADU (this exception does not apply to an ADU that is being constructed simultaneously with a new primary dwelling unit).
  • For a license or permit for a short-term rental on the parcel through a local law or program.

Impacts to Broomfield’s ADU code:

• Broomfield’s current code requires the property owner to occupy as their primary residence either the principal structure or the ADU on the lot. This will need to be changed to meet the state requirements outlined above.
• The Broomfield ADU code will still require property owners to prove residence at the time that an application is submitted to construct or convert an ADU, or to apply for a license for a short-term rental.
• The code will also still prohibit ADUs for use as a short-term rental, meaning any nightly rental such as AirBNB.

Parking Requirements

The new Colorado legislation also limits local governments from requiring the construction of new off-street parking spaces for ADUs. Limited exceptions include:

• If no existing off-street parking is available (driveway, garage, etc.), parking restrictions may be allowed.
• If the zoning district requires parking for a primary residence, but the block does not allow on-street parking, parking restrictions may be permitted.

Changes to Broomfield’s parking code as a result of the new Colorado legislation will be addressed by the concurrent 2025 proposed parking code update.

Broomfield City Council Guidance

At the January 21, 2025 City Council Study Session, Broomfield City Council expressed their support to move forward with modifications to Broomfield’s code. City and County of Broomfield staff are preparing a draft ordinance for Broomfield City Council to consider. City Council dates for this ordinance are listed in the Key Dates at the top of this page.

Public Engagement

Community feedback will be taken into consideration for elements of the proposed code update which the City and County of Broomfield has the authority to modify. Public feedback will not impact code requirements related to state requirements.

You can provide your feedback or ask questions using the tabs below. The deadline to provide feedback is May 2, 2025. Comments emailed to planning@broomfield.org will also be accepted until the day of the second reading listed in the Key Dates at the top of this page.