Fees
Estimated city fees
Baseline for a simple permitted addition: $600–$2,500+ estimated city fees for a permitted residential addition in Denver (varies by project valuation, trade permits billed separately)
| Fee | Amount | Notes |
|---|---|---|
| Building permit (valuation-based) | $600–$2,500+ (estimated range for typical room addition) | Denver permit fees are based on declared project valuation per the current fee schedule. Verify current amounts at denvergov.org/permits before submitting. |
| Plan review fee | Included or charged separately based on scope | Denver includes plan review in the building permit fee for most residential projects. Some complex or over-the-counter projects have separate review line items. |
| Mechanical permit | $100–$400 (estimated) | Required for HVAC extensions, new ducts, or equipment. Fees vary by scope. |
| Electrical permit | $100–$400 (estimated) | Required for new circuits, panels, or service changes associated with the addition. |
| Plumbing permit | $100–$400 (estimated) | Required for any new bathroom, laundry connections, or wet areas in the addition. |
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Conditions
The rules that apply
- Any addition that increases the enclosed floor area of a residential structure in Denver needs a building permit.
- Denver Development Services issues building permits for residential additions through its online permit portal.
- An addition with a bathroom, laundry room, or wet bar needs a plumbing permit in addition to the building permit.
- An addition that extends or adds HVAC equipment, ductwork, or a new furnace needs a mechanical permit.
- New electrical circuits, service upgrades, or subpanels for the addition need a separate electrical permit.
- Additions must comply with the Denver Zoning Code (DZC). Setbacks, lot coverage, height limits, and floor area ratio vary by zone district.
- Properties in Denver historic districts or on individually landmarked sites need a Certificate of Appropriateness from Denver Community Planning and Development before you get building permits.
- A conditioned addition must meet the 2021 International Energy Conservation Code (IECC) as adopted by Denver.
- An addition that changes the occupancy classification or adds a dwelling unit must follow the applicable residential code path.
Documents
What you'll need to file
- Building permit application submitted through the Denver eDevelopment portal.
- Site plan showing lot lines, setbacks, existing structures, proposed addition footprint, and impervious coverage.
- Floor plans for all affected levels showing existing and proposed layout, room dimensions, window and door locations.
- Exterior elevations showing existing and proposed building height and materials.
- Foundation and framing plan with structural details.
- Energy code compliance documentation under the 2021 IECC as adopted by Denver.
- Structural calculations or engineer-stamped drawings for non-prescriptive structural elements.
- Trade permit applications for mechanical, electrical, and plumbing work included in the addition scope.
- Certificate of Appropriateness from the Denver Landmark Preservation Commission if the property is in a historic district.
Process
How the permit process works
Each step must finish before the next one starts.
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Check zoning compliance Look up your parcel in Denver's My Neighborhood tool or use the Denver Zoning Code to confirm setbacks, lot coverage, height limits, and floor area ratio for your zone district. These rules set the maximum size and placement of your addition, so check them before you pay for drawings.
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Hire a designer or architect Residential additions in Denver typically need architectural drawings by a Colorado-licensed professional. An addition with complex structural elements also needs an engineer.
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Prepare a complete permit package Assemble the site plan, floor plans, elevations, structural details, energy compliance documentation, and all trade permit applications before submitting. A complete package means fewer correction cycles.
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Submit through the Denver eDevelopment portal Log into the eDevelopment portal, start a new residential addition permit application, upload all documents, and pay the required fees. Denver routes the application to the appropriate review staff.
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Respond to plan review corrections Reviewers check zoning compliance, structural details, energy code, and life safety. The city issues correction notices through the portal. Respond promptly with updated drawings and resubmit.
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Receive permit and post on site Once approved, pay any remaining fees, download the permit, and post it visibly on site before construction begins.
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Schedule inspections at required milestones Request inspections through the eDevelopment portal at required stages, typically foundation, framing, insulation, and final. Trade inspections have their own milestones. Do not cover work before it is inspected.
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Pass final inspection and close the permit After all inspections pass, the city closes the permit. Keep the final approvals for insurance, refinancing, and resale.
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Tools & materials
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Provenance
Code basis & official sources
Last verified 2026-05-07.
2021 International Residential Code (IRC) as adopted by Denver with local amendments. 2021 International Energy Conservation Code (IECC) for energy compliance. Denver Zoning Code (DZC) for land use and dimensional standards.
Residential permit page: https://www.denvergov.org/Government/Agencies-Departments-Offices/Community-Planning-and-Development/Building-Permits-Inspections/Online-Services-eDevelopment
If you skip the permit
- Denver Community Planning and Development can issue a stop-work order and require removal of unpermitted work.
- Retroactive permitting for a completed addition requires opening walls and framing for inspection, often at significant cost.
- Home inspectors and mortgage lenders routinely flag unpermitted additions. That can delay or derail a sale.
- Insurance may deny claims for unpermitted living areas.
- An appraisal may not count unpermitted square footage.
- If unpermitted work fails structurally, you may carry personal liability.
FAQ
Common Denver addition permit questions
Do I need a permit to add a room to my house in Denver?
Yes, always. Any addition that increases the enclosed living area or structural footprint of a Denver residential building needs a building permit. There is no size exemption for room additions.
How much does an addition permit cost in Denver?
Denver permit fees are valuation-based. A typical room addition costs about $600–$2,500+ in city permit and plan review fees. Trade permits (electrical, mechanical, plumbing) are billed separately. Verify current amounts at denvergov.org/permits.
How long does Denver plan review take for a room addition?
Standard residential addition review typically takes 3–6 weeks per review cycle in Denver. Total project duration, including design, corrections, construction, and inspections, is commonly 2–5 months.
Does my Denver addition need to meet energy code?
Yes. All conditioned additions in Denver must comply with the 2021 International Energy Conservation Code (IECC) as locally adopted. That typically means meeting insulation, window, and air-sealing requirements for Denver's climate zone.
My house is in a Denver historic district — does that change anything?
Yes. Properties in Denver landmark historic districts need a Certificate of Appropriateness from the Denver Landmark Preservation Commission before the city issues building permits. The COA review assesses whether the addition fits the historic character of the structure and neighborhood.
Do I need separate electrical and plumbing permits for my addition?
Yes. Electrical circuits, panels, or service upgrades need a separate electrical permit. Plumbing for bathrooms, laundry, or wet areas needs a plumbing permit. HVAC extensions or new equipment need a mechanical permit. File all trade permits alongside the main building permit.
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Disclaimer: Informational only, not legal advice. Rules change. verify with Denver permitting staff before you build.