Accessory Structures in Castle Rock, CO (2026)
5 verified accessory structures rules for Castle Rock, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Castle Rock allows accessory dwelling units, but no more than one ADU per lot. Before a building permit issues, the owner must record a deed restriction barring rental of both the primary home and the ADU at the same time, and no separate water/sewer taps are permitted.
Accessory Dwelling Units (ADUs) in Castle Rock
Some RestrictionsCastle Rock Mun. Code Ch. 17.61
No more than one (1) ADU may be created or maintained on a single lot. Prior to issuance of a building permit for an ADU, the property owner shall record a deed restriction... prohibiting the concurrent renting of both the Primary Dwelling Unit and the Accessory Dwelling Unit.
Shed Rules
Sheds and other detached accessory buildings are governed by Castle Rock's Zoning Code (Title 17). Accessory buildings must sit behind the primary home in the rear yard, meet reduced side/rear setbacks, and are capped at a lower height than the main house. Larger sheds also need a building permit.
Shed and Detached Accessory Structure Rules
Some RestrictionsGarage Conversions
Converting a garage into finished living space or an ADU requires a building permit in Castle Rock, submitted through the eTRAKiT Development Portal. If the converted space becomes a separate dwelling unit, it must comply with the Chapter 17.61 ADU rules, including the one-per-lot limit and recorded deed restriction.
Garage Conversions in Castle Rock
Some RestrictionsCarport Rules
A carport is an accessory structure and is regulated under Castle Rock's Zoning Code (Title 17) like other accessory buildings: it must respect required setbacks, meet the accessory-structure height limit, and typically requires a building permit. HOA covenants in many Castle Rock subdivisions add stricter design rules.
Carport Rules in Castle Rock
Some RestrictionsTiny Homes
Castle Rock has no dedicated tiny-home ordinance. A tiny house on a permanent foundation must meet the adopted International Residential Code (Title 15) and zoning district standards. A tiny house built as a second unit is regulated as an ADU under Chapter 17.61. Tiny houses on wheels (RVs) cannot be
Tiny Homes in Castle Rock
Some RestrictionsLooking for Douglas County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Castle Rock city rules.
Accessory Structures in Douglas County →