Denver County · Updated 2025
Denver ADU Permits: Fees, Timeline & Process
Three permits required — zoning, building, and SUDP. Colorado's 2024 law now opens all residential zones.
Quick Answer
Denver ADUs: $180K–$450K
Permits: $7K–$30K · Updated April 2026
Denver ADU Permitting: Overview
Denver processes ADU permits through its e-permits online system, which allows homeowners and contractors to submit applications, upload plans, and track review status without visiting city hall. The city offers simultaneous zoning and building permit review, which can meaningfully compress the overall timeline. Three permits are required for most ADU projects: a zoning review permit, a building permit, and a Sewer Use and Drainage Permit (SUDP).
Colorado's 2024 statewide ADU law (HB24-1152) now requires all municipalities — including Denver — to allow ADUs in residential zones. This eliminated many of the zone-by-zone restrictions that previously complicated permitting. ADUs are now permitted across virtually all Denver residential zones, removing the need for variance applications in most cases.
Permit Fee Breakdown
| Permit / Fee | Cost | Notes |
|---|---|---|
| Zoning Review | $500–$2,000 | Required for all ADU types; simultaneous review available |
| Building Permit | $3,000–$8,000 | Based on construction valuation; larger ADUs cost more |
| SUDP (Main House) | $632 | Sewer Use and Drainage Permit for existing structure |
| SUDP (ADU) | $632 | Separate SUDP required for each dwelling unit |
| Other Fees (utility connections, plan review, etc.) | Varies | New utility connections for detached ADUs add $10K–$25K |
| Total Estimated | $7,000–$30,000+ | Larger detached ADUs approach or exceed $30K |
Fee ranges are estimates. Verify current fees at denvergov.org before submitting. Updated 2025.
ADU Requirements in Denver
Zoning Eligibility
Per Colorado's 2024 ADU law, ADUs are now allowed in all residential zones in Denver. There is no longer a need to verify zone-specific ADU eligibility in most cases. Properties in historic districts (e.g., parts of Capitol Hill, Curtis Park, Potter-Robbins) require a Certificate of Appropriateness from Denver Landmark Preservation in addition to standard permits.
Setbacks and Height
Setback requirements vary by zone. Detached ADUs typically require 5-foot side and rear setbacks, though this varies by zone designation. Height limits for detached ADUs range from 24 to 35 feet depending on zone. Attached ADUs and conversions must comply with the setbacks already established for the main structure. Confirm zone-specific requirements through Denver's My Neighborhood tool before designing.
Owner-Occupancy and HOA Restrictions
Colorado's 2024 law eliminated owner-occupancy requirements statewide. You do not need to live on the property to permit or rent an ADU. HOAs may impose reasonable design standards (materials, roof pitch, paint colors) but cannot prohibit ADU construction outright. Review your CC&Rs with an attorney to understand what design constraints may apply to your HOA community.
Permit Timeline
| Phase | Typical Duration | Notes |
|---|---|---|
| Feasibility & Zoning Check | 1–2 weeks | Verify zone, setbacks, lot coverage via denvergov.org |
| Design & Engineering | 1–3 months | Architect drawings + structural engineering for snow loads |
| Permit Submission | 1 week | Submit via Denver e-permits; simultaneous review recommended |
| City Plan Review | 3–6 months | Historic district review adds additional time |
| Permit Issuance | 1–2 weeks | After plan review approval and fee payment |
| Construction + Inspections | 4–12 months | Varies by ADU type; basement conversions are faster |
| Certificate of Occupancy | 1–2 weeks | Final inspection must pass before occupancy |
| Total Typical Timeline | 10–18 months | Start to move-in ready |
Step-by-Step Permit Process
Feasibility and Zoning Check
Use Denver's My Neighborhood portal to verify your zone designation, allowed ADU types, setback requirements, and lot coverage limits. Confirm whether your property is in a historic district, which triggers additional review.
Design and Engineering
Hire a licensed architect and structural engineer. Denver requires engineering drawings that address Colorado's snow load requirements (40–60 lb/sq ft) and frost-depth foundations. Detached ADUs need full site plans, floor plans, elevations, and structural drawings.
Submit Through e-Permits
Create an account at denvergov.org/epermits and submit your zoning review application and building permit application. Request simultaneous review at submission to save time. Upload all required drawings, site plans, and supporting documents digitally.
Plan Review
Denver's Development Services reviews your application for zoning compliance, building code compliance, and SUDP requirements. Reviewers may issue correction comments requiring revised drawings. Historic properties also undergo Landmark Preservation review during this phase.
Permit Issuance
After plan review approval, pay all permit fees through the e-permits portal. Permits are issued digitally. Keep digital copies accessible during construction for inspector access.
Construction and Inspections
Construction proceeds in phases with mandatory city inspections at key milestones: foundation, framing, rough electrical/plumbing, insulation, and final inspection. All inspections must be scheduled and passed before advancing to the next phase.
Certificate of Occupancy
After passing final inspection, Denver issues a Certificate of Occupancy (CO). The ADU cannot be legally occupied or rented until the CO is issued. Allow 1–2 weeks for the CO to be processed after final inspection approval.
Estimate Your Denver ADU Costs
See total project costs including permits, construction, and financing for your specific ADU type.
Get Your EstimateFrequently Asked Questions
How long does it take to get a Denver ADU permit?
Denver ADU permit review typically takes 3–6 months. Using the simultaneous zoning and building review option can reduce total review time. Historic district properties require an additional Certificate of Appropriateness from Denver Landmark Preservation, which adds time. The full project timeline from initial design to certificate of occupancy is typically 10–18 months.
How much do Denver ADU permits cost?
Denver ADU permit fees total $7,000–$30,000+ depending on ADU size and type. This includes a zoning review permit ($500–$2,000), building permit ($3,000–$8,000), and two Sewer Use and Drainage Permits (SUDP) at $632 each — one for the main house and one for the ADU. Detached ADUs with new utility connections can add $10,000–$25,000 in utility tap fees on top of permit costs.
Do I have to live on the property to rent a Denver ADU?
No. Colorado's 2024 statewide ADU law (HB24-1152) eliminated owner-occupancy requirements across the entire state. You are not required to live on the property to permit or rent an ADU in Denver. This was a significant change from prior rules that restricted non-owner-occupied ADU rentals in some zones and is one of the most impactful provisions of the 2024 law for investors and landlords.
Can an HOA stop me from building an ADU in Denver?
No. Colorado's 2024 ADU law limits HOA authority over ADU construction. HOAs cannot outright prohibit ADUs on a property. However, HOAs may impose reasonable design and aesthetic standards — such as requiring exterior materials to match the main house, limiting roof pitch options, or restricting paint colors. Denver homeowners in HOA communities should review their CC&Rs and consult with a real estate attorney before finalizing ADU design plans.
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