ADU Rules in Denver, Colorado

Complete guide to building an Accessory Dwelling Unit in Denver — zoning, setbacks, permits, costs, and more.

Max Size: Up to 1,000 sq ft on lots over 7,000 sq ft (864 sq ft on 6,000-7,000 sq ft lots; ~650 sq ft on smaller lots) — varies by zone district Setbacks: Must be within rear 35% of lot; 5 ft minimum rear setback No Parking Required Verified: 2026-07-01
ADU Score: 8/10
Very ADU-friendly · how we score

Denver is highly ADU-friendly, allowing detached and attached units in every zone that permits a single-family dwelling (citywide as of CB24-1303, Dec 2024) with streamlined administrative approval. The city's emphasis on infill development and housing affordability makes it one of the nation's better ADU markets.

Zoning & Size Requirements [1][2]

Yes, you can build an ADU in Denver. A detached ADU can be up to the city's size limit under current Colorado and Denver zoning rules.

Allowed ZonesAll zones that allow a single-family dwelling (citywide as of CB24-1303, effective Dec 16, 2024)
Max Size (Detached)Up to 1,000 sq ft on lots over 7,000 sq ft (864 sq ft on 6,000-7,000 sq ft lots; ~650 sq ft on smaller lots) — varies by zone district
Max Size (Attached)Up to 1,000 sq ft (varies by zone district)
Max Size (JADU)Confirm with Denver CPD (Denver regulates ADUs, not a separate JADU category)
Max Height24 ft / 1.5 stories maximum
Max Units1 ADU per single-family lot

Setback Requirements [1][2]

Denver requires a rear setback of about 35 ft for a detached ADU, and no additional parking is required. Owner-occupancy is not required — you can rent it out without living on the property.

Rear SetbackMust be within rear 35% of lot; 5 ft minimum rear setback
Side SetbackVaries by lot width (typically 3-5 ft); confirm with Denver CPD
Front SetbackMatches the primary structure front setback (varies by zone); a 15 ft separation is required between the house and the ADU
Parking RequiredNot required (no parking minimum for ADUs per HB24-1152 / CB24-1303)
Owner OccupancyNot required (removed by CB24-1303, effective Dec 16, 2024; consistent with CO HB24-1152)
Min Lot SizeNo minimum lot size (removed by CB24-1303)

Permit Process & Fees [3]

An ADU permit in Denver typically costs $500-$5,000 building permit + ~$2,055 Denver Water SDC (rising to $2,170 on Jul 1, 2026); total permit/utility typically $6K-$10K and takes 4-7 months realistic from application to issued permit (zoning + building review), through a ministerial, by-right review.

Approval ProcessAdministrative (by-right) approval — no public hearing
Review Timeline4-7 months realistic from application to issued permit (zoning + building review)
Permit Fees$500-$5,000 building permit + ~$2,055 Denver Water SDC (rising to $2,170 on Jul 1, 2026); total permit/utility typically $6K-$10K
Impact FeesDenver Water system development charge applies; see fees
Plan CheckSeveral weeks to a few months depending on backlog
Pre-Approved PlansPre-approved/standard plan options available

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Construction Costs [4][5]

Building an ADU in Denver typically costs $140,000-$280,000 ($130-$260 per sq ft); a garage conversion runs $70,000-$160,000.

Average Build Cost$140,000-$280,000
Cost per Sq Ft$130-$260
Garage Conversion$70,000-$160,000
Prefab ADU (Installed)$100,000-$230,000

Finance Your ADU Project

Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.

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Rental Income Potential [6][7]

A 2-bedroom ADU in Denver rents for around $1,800-$2,500/mo, an estimated 7-9% annual return.

Avg Rent (1 Bedroom)$1,400-$1,900/mo
Avg Rent (2 Bedroom)$1,800-$2,500/mo
Short-Term RentalYes, with STR license
Est. Annual ROI7-9% annual return

Explore Prefab ADU Options

Prefab ADUs can save 20-40% vs. traditional construction and cut build time in half.

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Recent Law Changes

What's Changed Recently

  • Colorado ADU Grant Program (HB24-1152) Round 3 runs Aug 3-31, 2026 - funds go to certified local governments, not directly to homeowners; if Denver participates, residents may see subsidized pre-approved plans or reduced fees
  • Denver CB24-1303 (Dec 2024) fully in effect: ADUs in all residential zones, no lot size min, no owner-occupancy
  • Permit fees: $500-$5,000 building + ~$2,055 Denver Water SDC (rising to $2,170 on Jul 1, 2026). Total permit/utility typically $6K-$10K
  • Realistic permit timeline: 4-7 months from application to issued permit

Tips for Building an ADU in Denver

  • Denver's by-right approval means fastest permitting timeline
  • Tech and service industry growth ensures strong rental demand
  • Short-term rental market strong; explore vacation rental opportunities
  • Pre-approved plans available; maximize timeline efficiency

ADU Builders in Denver

Looking for an ADU builder in Denver? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match Denver homeowners with experienced local ADU contractors who provide free, no-obligation quotes. Getting at least three bids typically saves 20-40% on the same scope.

Sources & References

All data on this page is sourced from official government records and verified market data. View our full methodology.

  1. Accessory Dwelling Units (ADUs) in Denver Planning Department — Accessed 2026-02-24
  2. Citywide ADU Zoning Text Amendment (CB24-1303, eff. Dec 16, 2024) Municipal Code — Accessed 2026-06-28
  3. ADU Permits | Denver CPD Planning Department — Accessed 2026-02-24
  4. Angi — ADU Construction Cost Data Market Data — Accessed 2026-02-24
  5. Angi — Local ADU Contractor Costs Market Data — Accessed 2026-02-24
  6. Zillow Rental Manager — Market Rent Data Market Data — Accessed 2026-02-24
  7. HUD Fair Market Rents Government Data — Accessed 2026-02-24
  8. Denver ADU Interactive Map Planning Department — Accessed 2026-02-24
  9. Colorado ADU Legislation (HB 24-1152) Government Data — Accessed 2026-02-24
  10. Denver CB24-1303 Ordinance — Citywide ADUs (City Council, eff. Dec 16, 2024) Municipal Code — Accessed 2026-06-28

Frequently Asked Questions

Can I build an ADU in Denver?

Yes. ADUs are allowed in All zones that allow a single-family dwelling (citywide as of CB24-1303, effective Dec 16, 2024) in Denver. The maximum size for a detached ADU is Up to 1,000 sq ft on lots over 7,000 sq ft (864 sq ft on 6,000-7,000 sq ft lots; ~650 sq ft on smaller lots) — varies by zone district. Owner-occupancy is not required, so you can rent out the ADU.

How much does an ADU cost in Denver?

ADU construction in Denver typically costs $140,000-$280,000. Garage conversions run $70,000-$160,000, and prefab ADUs cost $100,000-$230,000.

How much can I rent an ADU for in Denver?

Average ADU rents in Denver are $1,400-$1,900/mo for a 1-bedroom and $1,800-$2,500/mo for a 2-bedroom unit.

Do I need parking for an ADU in Denver?

Not required (no parking minimum for ADUs per HB24-1152 / CB24-1303). Check with Denver planning department for the latest Colorado ADU parking rules, as many states have relaxed requirements in recent years.

How long does it take to get an ADU permit in Denver?

The permit review timeline in Denver is 4-7 months realistic from application to issued permit (zoning + building review). Fees range from $500-$5,000 building permit + ~$2,055 Denver Water SDC (rising to $2,170 on Jul 1, 2026); total permit/utility typically $6K-$10K.

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