An Accessory Dwelling Unit (ADU) is an additional dwelling that can either be added to an existing single
family detached dwelling, or built as a separate accessory structure on the same lot as the primary dwelling.

Each Metro Denver County regulates zoning and allowable living units as well as legal uses based upon the local planning and zoning regulations. For your convenience, we have compiled a short list with links to the applicable websites.  Rules permit requirements and regulations change often, so make sure to contact the local planning and zoning department before making a property purchase or modifications involving an Accessory Dwelling Unit (ADU).

Adams County
https://www.adcogov.org/residential-building-permits
https://www.adcogov.org/sites/default/files/2017%20Accessory%20Building%20WEB.pdf

Arapahoe County
https://www.co.arapahoe.co.us/653/Zoning
https://www.arapahoegov.com/DocumentCenter/View/1184/Chapter-19?bidId=

Broomfield County


Boulder County


Denver County


Douglas County


Jefferson County
https://www.jeffco.us/FAQ.aspx?TID=37
https://www.jeffco.us/DocumentCenter/View/11947/Accessory-Dwelling-Unit-ADU?bidId=