Garage Conversion Guide

Garage Conversion in Denver, CO: Cost, Permits & Rules (2026)

Turning your garage into a legal ADU is the cheapest, fastest way to add a rentable unit in Denver. Here's what it costs, what the permit takes, and the rules that matter.

$70,000-$160,000Typical Cost
4-7 months realistic from application to issued permitPermit Timeline
NoneReplacement Parking

A garage conversion is usually the lowest-cost path to an ADU in Denver — $70,000-$160,000, versus $140,000-$280,000 for a new detached build — because the shell already exists.

Garage Conversion Cost in Denver

Converting an existing garage in Denver runs $70,000-$160,000. That's well under the $140,000-$280,000 typical cost of a ground-up detached ADU, because you're reusing the foundation, walls, and roof. The biggest variables are whether the slab and framing are sound, what utility/electrical upgrades are needed, and your finish level. Permit fees add $500-$5,000 building permit + $2,055-$3,030 Denver Water SDC; total permit/utility typically $7K-$13K. A converted unit rents for about $1,400-$1,900/mo (1BR) in Denver.

The Denver Garage Conversion Permit Process

A garage-to-ADU conversion in Denver needs building permits even if the exterior is unchanged. Approval process: Administrative (by-right) approval — no public hearing The review timeline is 4-7 months realistic from application to issued permit (zoning + building review), with plan check: Several weeks to a few months depending on backlog. Pre-approved plans: Pre-approved/standard plan options available.

  1. Confirm eligibility — ADUs are allowed in All zones that allow a single-family dwelling (citywide as of CB24-1303, effective Dec 16, 2024).
  2. Prepare conversion plans — layout, egress windows, insulation, ventilation, smoke/CO detectors, plus a kitchen and bathroom.
  3. Submit for plan check — Several weeks to a few months depending on backlog.
  4. Pull permits and build — fees run $500-$5,000 building permit + $2,055-$3,030 Denver Water SDC; total permit/utility typically $7K-$13K; then framing, electrical, plumbing, and final inspection.

Parking Rules for a Garage Conversion

Not required (no parking minimum for ADUs per HB24-1152 / CB24-1303) Garage conversions sometimes trigger different parking rules than new detached ADUs, so confirm replacement-parking requirements with Denver before you start. Owner-occupancy is not required, so you can rent the converted unit out.

The JADU Option for an Attached Garage

If your garage is attached to the house, you can convert it into a junior ADU (JADU) — capped at Confirm with Denver CPD (Denver regulates ADUs, not a separate JADU category) and built within the existing walls. JADUs are cheaper and faster to permit than a full ADU, though they may share sanitation with the main home. A full ADU gives you more size and a separate unit; a JADU is the budget route.

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Denver Garage Conversion FAQ

How much does a garage conversion cost in Denver?

A garage conversion in Denver typically costs $70,000-$160,000 — well below the $140,000-$280,000 cost of a new detached ADU, because the foundation, walls, and roof already exist. Budget separately for permit fees ($500-$5,000 building permit + $2,055-$3,030 Denver Water SDC; total permit/utility typically $7K-$13K) and any electrical or utility upgrades the conversion triggers.

Do I need a permit to convert a garage in Denver?

Yes. Converting a garage to a living unit in Denver requires building permits even if the exterior stays the same — the work has to meet code for insulation, egress, ventilation, electrical, and a kitchen/bathroom. The ADU permit timeline is 4-7 months realistic from application to issued permit (zoning + building review), and the process is: Administrative (by-right) approval — no public hearing

Do I have to replace the parking if I convert my garage in Denver?

Not required (no parking minimum for ADUs per HB24-1152 / CB24-1303) Garage conversions sometimes trigger different parking rules than new detached ADUs, so confirm replacement-parking requirements with Denver before you start.

How long does a garage conversion take in Denver?

Plan on 4-7 months realistic from application to issued permit (zoning + building review) for permit review (Several weeks to a few months depending on backlog for plan check), then construction. A garage conversion is usually faster to build than a ground-up ADU because the structure already exists.

Can I convert an attached garage into a JADU in Denver?

If the garage is attached to the house, yes — a junior ADU (JADU), capped at Confirm with Denver CPD (Denver regulates ADUs, not a separate JADU category), can be carved out of the existing footprint, which includes an attached garage. JADUs are cheaper but may share sanitation with the main home.

Compare your options: see the full Denver ADU rules, estimate your build with the Denver ADU cost calculator, or read the general garage conversion guide.

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