Council amends ADU rules to allow Longmont residents to add units on other owned properties

Longmont’s City Council amended and approved an ordinance to streamline administrative approval of accessory dwelling units and broaden eligibility for who may build them. On second reading the council approved Ordinance 2025-35 as amended.

The amendment adopted Tuesday allows any person who is a Longmont resident at the time of application to build an ADU on another property they own in the city; prior draft language required the owner to live in the primary dwelling on the same lot. Councilors said the change will give residents more flexibility to add housing without requiring purchase of an additional house. The ordinance passed 5-2; Council members Diane Christ and Michael McCoy voted no.

Councilors discussed the policy’s intent to encourage gentle infill — ADUs that provide housing options such as mother-in-law apartments, small homes for caregivers or additional rental income — while trying to avoid unintended conversions into investor-controlled housing. Supporters in public comment urged further flexibility including allowing ADUs to be rented as short-term rentals; opponents and some council members said short-term rentals should be considered in a separate, comprehensive review.

Mayor Pro Tem Susie Hidalgo Fearing moved the amendment to allow Longmont residency (rather than occupancy of the primary dwelling) at the time of application; Council member Robert Popkin said the change can make it easier for local residents to add an ADU instead of buying another property. “This actually creates more for-sale options for people,” Popkin said in debate.

Councilors asked staff to return with any needed clarifications and to pursue a separate discussion of short-term rentals at a later date. The ordinance implements administrative ADU approvals under Title 15 of the Longmont Municipal Code and will be scheduled for the second reading/public hearing.