Colorado ADU Pro
Independent ADU Research for Colorado Homeowners

Denver Metro ADU Costs, Rules & Builder Guidance

The independent research tool for Denver metro homeowners exploring ADUs. Compare costs, understand Colorado’s ADU law, check your HOA eligibility, and find vetted builders — before committing to anything.

Get My Free ADU Estimate

What Homeowners Research Here

  • ✓  Backyard cottage costs in my neighborhood
  • ✓  Whether my HOA can stop me (it can’t)
  • ✓  Garage conversion vs. new construction
  • ✓  Financing options without refinancing
  • ✓  How to find and vet builders
14
Denver Metro Markets Covered
From Golden to Castle Rock
8+
ADU Financing Options
HELOC, ADU loans, cash-out refi
$1,500–$2,800
Typical Monthly Rent
Based on Denver metro 1BR units
12
Builder Questions to Ask
Before signing any contract

Compare ADU Types Side by Side

Independent cost ranges and trade-offs — so you know what questions to ask before talking to a contractor.

Backyard Cottage

Backyard Cottage

$170K–$400K
Highest rental income & resale value
See cost breakdown →
Garage Conversion

Garage Conversion

$45K–$145K
Fastest path, preserves existing structure
See cost breakdown →
Basement ADU

Basement ADU

$35K–$120K
Most affordable, uses existing footprint
See cost breakdown →

Research Your ADU Before Talking to a Single Builder

Think of this like NerdWallet for ADUs — independent information that helps you understand your options before you commit to anything.

1

Research Your Property

Understand what your lot allows, what HOA rules apply, and what permit process to expect — before spending money on plans.

2

Compare Your Options

See cost ranges for your ADU type, financing options, and projected rental income — so you go into builder conversations with real numbers.

3

Get Matched to Builders

When you’re ready to move forward, we refer you to vetted Colorado ADU builders who specialize in your project type and jurisdiction.

Denver Metro Area Guides

City-by-city ADU rules, permit requirements, and cost ranges. Each jurisdiction is different — find yours.

Common Questions

How much does an ADU cost in Colorado?

Basement conversions run $35K–$120K. Garage conversions $45K–$145K. Detached backyard cottages $165K–$400K. Costs vary significantly by city, lot conditions, and finishes. Use our quiz to get a range specific to your property type.

Can my HOA stop me from building an ADU?

No. Under Colorado’s HB 24-1152 (effective June 30, 2025), HOAs in subject jurisdictions cannot ban ADU construction. They can require exterior materials to match the primary home, but they cannot deny your project outright.

Do I need to live on the property?

Owner-occupancy requirements vary by city. Denver requires the owner to reside on the property when the ADU is completed. Most other metro cities do not require ongoing owner-occupancy for long-term rentals. Check your specific city’s rules.

How long does it take to get an ADU permitted?

Administrative review (no public hearing) typically takes 6–22 weeks depending on the city and project complexity. Basement conversions tend to permit faster than new detached construction. Having complete, professional plans from the start reduces review cycles significantly.

Start with the Free ADU Research Tool

Answer 7 questions about your property and goals. Get your estimated cost range, best ADU type match, and HOA eligibility — in about 2 minutes. No sign-up. No sales call.