The objective of this council priority is to consider an ordinance to remove saturation limits for Accessory Dwelling Units within a certain radius to allow for attached or detached ADUs wherever existing requirements are met.

  1. Plan

  2. Community Engagement

  3. Design

  4. Complete

Project Overview

The objective of this council priority is to increase the allowance of Accessory Dwelling Units (ADUs) in the community.


An accessory dwelling unit, also known as an “in-law apartment” or “garage flat” or “ADU,” is an additional living unit that has separate kitchen, sleeping and bathroom facilities, attached or detached from the primary residential unit on a single-family lot. The first ordinance allowing accessory dwelling units in Boulder was adopted in 1983. The regulations have been updated over time, with the most recent updates in 2018 and 2019.

Accessory dwelling units have been discussed as one tool to address Boulder’s housing challenges over the past decade or more to help provide “a diversity of housing types and price ranges,” which is a core value of the Boulder Valley Comprehensive Plan. The current regulations limit the percentage of ADUs within a certain radius in some zoning districts (a “saturation limit”) and establishes a waiting list for properties that are in areas that have reached their saturation limit.

Next Council Action

Council will hold a Study Session or Matters item to check in on the scope of the work in Q3.

Projected Timeline

  • Jul. – Sept. 2022: Initial scoping. Review 2018 analysis of Boulder’s ADU regulations. Identify laws and administrative actions that are barriers to the construction of ADUs in Boulder.
  • Oct. 2022: City Council matters item to discuss scoping and options.
  • Nov. 2022 – Mar. 2023: Draft and adopt amendments to land use code. Begin implementation of changes.