Yes, a garage can usually become an ADU in Denver. As of October 2026, Denver's 2023 ADU amendments removed zoning barriers to converting existing structures such as garages. The building itself still has to meet residential code, so the garage's condition decides how much of it you can keep.
What did Denver change for garage conversions?
The ADU amendments that took effect July 5, 2023 removed zoning barriers to converting existing accessory structures, garages included. They also extended the lot coverage exemption Denver gives vehicle parking structures to ADUs, which helps on lots that are already close to their coverage limit.
What does an old garage usually need?
- A foundation check. Many older garages sit on a thin slab without footings sized for a dwelling.
- Insulation and windows. Walls, roof and slab edges need insulating to Denver's adopted energy code.
- Utilities. A sewer connection, water service and an electrical feed sized for a kitchen and heating.
- Egress and light. Bedroom windows sized for emergency escape.
- Its own address. Denver requires each ADU to have its own address.
Do I have to replace the parking I lose?
Generally no. Colorado's HB24-1152 bars subject jurisdictions such as Denver from requiring added parking for an ADU, with narrow exceptions. A city may ask you to designate an existing space, and may require a new one only if the zone required parking as of January 1, 2024, no existing space is available, and on-street parking is banned on the block. That reflects the statute as of October 2026.
What does a garage conversion cost in Denver?
One 2026 national guide (Block Renovation) says Denver garage conversions start around $140,000. A garage in good shape near the house's sewer line costs less to convert than one that needs a new slab and a long trench. We inspect before we price.
When is converting the wrong call?
It depends on the structure. If the slab is cracked and the framing is undersized, rebuilding on the same footprint can cost close to a new detached ADU while keeping the old garage's awkward dimensions. In that case we price both options side by side.