Council directs staff to draft ADU ordinance aligning Castle Rock code with state law and streamlining approvals

The Town Council on April 15 directed staff to return with an ordinance amending Castle Rock’s accessory dwelling unit (ADU) regulations. Council's direction followed a staff presentation outlining the town’s existing ADU code (adopted in 2018) and proposed updates to align with state law and to address practical permitting concerns.

Planner Tara Vargas reviewed the current code and proposed changes. Under the existing code the town allows internal ADUs to be approved administratively but requires detached ADUs or additions to undergo use-by-special-review (public hearings with notice). The code also requires the property owner to occupy one of the units (enforced by a recorded deed restriction) and limits interior ADUs to 50% of the primary home (detached/additions limited to an 800-square-foot footprint). Vargas summarized House Bill 24-1152 (referred to in the staff presentation as HB 241152), a 2024 state law that requires municipalities to allow ADUs and sets some minimum standards.

Staff proposed the following principal changes, which Vargas said would also bring the town into compliance with state law: - Allow ADUs in all residential zones (remove the existing limited PD prohibition). - Make approvals administrative for internal and detached ADUs, rather than requiring public use-by-special-review hearings for detached units. - Remove the recorded-deed restriction requirement that enforces owner occupancy (the state law does not permit continuing local occupancy mandates). Staff noted the town may regulate ADUs and primary units the same way for short-term rentals if the town adopts short-term rental regulations in future. - Clarify setback rules by aligning ADU accessory setbacks with accessory structure setbacks, or, where none exist, require a minimum 5-foot rear setback; maintain the existing 800-square-foot detached footprint limit and apply a state minimum interior ADU size (staff noted the state sets a 750-square-foot minimum for ADUs).

Council members asked about enforceability of owner-occupancy provisions, the interaction between ADU rules and short-term rental regulations, and how the existing 50% interior size rule interacts with small homes. Tara Vargas said enforcement of an ongoing owner-occupancy requirement is limited in practice and removing the recorded-deed restriction would align the town with state law. Staff agreed to provide a short update on short-term rental data and options when drafting the ordinance.

A motion to direct staff to bring back an ADU ordinance amendment was moved by Councilmember Bracken and seconded by Councilmember Hollingshead; the motion passed 6–1 in roll call (Mayor Pro Tem Kavey voted no).