Residential permit rules in Colorado
Representative cities: Denver, Colorado Springs. Covers 20 common home projects.
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | city | Valuation-based; set by the issuing city/county. | — | Case by case | Colorado is a home-rule state with no mandatory statewide residential code, so ADU rules vary by jurisdiction. Denver allows ADUs by right through its e-permits process; other cities/counties differ. When permitted by zoning, a full building permit is required. |
| 🪵 Deck / Porch | Conditional | city | Valuation-based; set by the issuing city/county. | — | Generally allowed | Some cities also require a permit for any deck attached to the house because of the structural connection. Mountain/WUI communities may require fire-resistant decking. Exempt: Most Colorado cities require a permit for decks >30 in above grade or >200 sq ft; ground-level decks below both are generally exempt. Denver and Colorado Springs follow IRC thresholds. |
| 🧱 Fence / Wall | Conditional | city | Usually no building permit for fences under 6–7 ft; zoning approval may be required. | — | Generally allowed | Front-yard and corner-lot fences have additional height/setback rules. Exempt: PPRBD exempts fences <7 ft (Colorado Springs requires zoning approval at ≥6 ft); Denver fences are generally permit-exempt under 6 ft. |
| 🛖 Shed / Outbuilding | Conditional | city | Valuation-based; set by the issuing city/county. | — | Generally allowed | Zoning setback and lot-coverage rules still apply. Exempt: PPRBD exempts detached accessory structures <200 sq ft (Colorado Springs zoning approval at ≥125 sq ft); IRC exempts ≤120 sq ft. |
| 🪜 Basement Finish | Permit required | city | Valuation-based; includes trade permits. | — | Generally allowed | Finishing a basement to living space requires framing, electrical, plumbing, and mechanical permits; bedrooms need egress windows. |
| 🚗 Garage / Carport | Permit required | city | Valuation-based; includes trade permits. | — | Generally allowed | New attached or detached garages require a full building permit and trade permits. |
| ☀️ Rooftop Solar PV | Permit required | city | Building + electrical permits; fee set by the city/county. | — | Generally allowed | Denver and many Colorado jurisdictions encourage solar; building + electrical permits required, with structural/snow-load review. |
| 🌡️ HVAC Replacement | Conditional | city | Mechanical permit; fee set by the city/county. | — | Generally allowed | Mountain/WUI communities may add fire-safety siting rules for equipment. |
| 🍳 Kitchen Remodel | Conditional | city | Valuation-based when structural, plumbing, or electrical work is included. | — | Generally allowed | Energy-code triggers apply to remodels. |
| 🛁 Bathroom Remodel | Conditional | city | Valuation-based when plumbing is relocated. | — | Generally allowed | Ventilation to the exterior is required. |
| 🏗️ Room Addition | Permit required | city | Valuation-based; includes trade permits. | — | Generally allowed | Any new conditioned footprint requires a building permit, setback/zoning review, and trade permits. Snow loads at altitude affect design. |
| 🪟 Window / Door Replacement | Conditional | city | Usually no fee for in-kind swaps; a permit is needed if the opening is enlarged. | — | Generally allowed | Replacement products must meet the energy code when triggered. Exempt: Same-size, in-kind window/door replacement is generally exempt. |
| 🏘️ Roof Replacement | Conditional | city | Often over-the-counter or exempt for same-footprint re-roof. | — | Generally allowed | Snow-load and ice-dam requirements are reviewed for roof assemblies. Exempt: Same-material, same-slope re-roof is often exempt or over-the-counter; structural deck changes require a permit. |
| 🅿️ Driveway / Parking Pad | Conditional | city | Building permit often not required; curb-cut/right-of-way work is separate. | — | Generally allowed | Mountain/WUI drainage and erosion-control rules may apply; right-of-way permit for curb cuts. Exempt: Replacing a driveway in the same footprint (no new curb cut) is generally exempt. |
| 🏊 Swimming Pool / Spa | Permit required | city | Valuation-based; includes barrier/fencing and electrical bonding review. | — | Generally allowed | Code-compliant barrier required; WUI/mountain communities may add fire-safety rules for pool equipment. |
| 🧱 Retaining Wall | Conditional | city | Valuation-based when over the height threshold. | — | Generally allowed | Sloped mountain lots often trigger engineered retaining-wall requirements. Exempt: PPRBD requires a permit for retaining walls >4 ft; walls ≤4 ft not supporting a surcharge are generally exempt. |
| 💥 Demolition / Teardown | Permit required | city | Valuation-based; set by the issuing city/county. | — | Generally allowed | A demolition permit is required before tearing down a house or attached structure. Local building departments require utility disconnects (electric, gas, water, sewer) and an asbestos/lead-paint clearance for pre-1978 homes before demolition. Mountain/WUI communities may add fire-safety rules for demolition debris. |
| 🚰 Septic System | Permit required | county | Permit fee set by the county/ district health department; engineered systems cost more. | — | Generally allowed | New or replacement onsite wastewater (septic) systems require a permit under Colorado Regulation 43 (CDPHE), administered by county/district health departments. A soil/perc evaluation and engineered design are typically required; conventional and alternative systems are reviewed for site suitability. |
| 🔌 EV Charger | Conditional | city | Electrical permit; fee set by the city/county. | — | Generally allowed | Home EV charging (240V branch circuit + wall-mounted EVSE) requires an electrical permit and must meet the NEC (Article 625). Many Colorado jurisdictions fast-track residential EVSE. A load calculation and possible service upgrade are reviewed. |
| ⚡ Standby Generator | Conditional | city | Mechanical/electrical permit; fee set by the city/county. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. Mountain/WUI communities may add fire-safety siting rules. |
Frequently asked questions
Do I need a building permit for home projects in Colorado?
Most structural, electrical, plumbing, and mechanical work does. The project table above shows Colorado-specific permit requirements for 20 common home projects. Always confirm with the local building department before starting.
Who issues building permits in Colorado?
Colorado permit authorities are typically city or county building departments. Use the county permit authority lookup to find the exact office for your property.
Which home projects are exempt from permits in Colorado?
Common baseline exemptions apply widely: detached sheds ≤120 sq ft, fences ≤6–7 ft, decks ≤30 in above grade, same-footprint re-roofs, and in-kind window/door swaps. Colorado or your city may amend these — verify locally.
How much does a permit cost in Colorado?
Permit fees are set by each city or county and scale with project valuation; there is no single Colorado statewide fee. Open the official authority link on this page for the local fee schedule.