Building permits in Natrona County, Wyoming
Find the right authority before you build. Natrona County permitting follows Wyoming law — here is exactly who issues the permit and where to start.
Cities issue permits
City of Casper issues building permits; unincorporated Natrona County may have no local building-permit requirement
Natrona County has no county-wide building-permit department; permitting is handled by its municipalities. The City of Casper (the county seat and most populous place) runs a Building Inspection Division under the 2024 I-Codes.
Open the official permit portal →
Casper permits and inspections are handled through the city CSS portal (casperwy.gov). Unincorporated parts of Natrona County may not require a local building permit — confirm with the county.
Permit cheat-sheet (Wyoming rules)
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Conditional | city | Valuation-based where a building department enforces (e.g., Cheyenne). | Plan review through the local building department. | Generally allowed | Wyoming has NO mandatory statewide residential building code — Cheyenne, Casper, and other cities adopt the IRC locally (Cheyenne is on the 2024 I-Codes). Much unincorporated county land has no building permit at all. Verify with your local building department. Exempt: Local zoning sets size, setback, and parking limits. |
| 🪵 Deck / Porch | Conditional | city | Valuation-based where enforced. | Over-the-counter or 1–3 weeks depending on complexity. | Generally allowed | Cheyenne footings must address high wind and deep frost; verify with the building department. Exempt: Decks ≤30 in above adjacent grade are exempt under IRC R105.2. |
| 🧱 Fence / Wall | Conditional | city | Set by the city; often low or over-the-counter. | Often same-day/over-the-counter for standard fences. | Generally allowed | Pool-enclosure fences must meet barrier requirements regardless of height. Exempt: IRC R105.2 exempts fences ≤6 ft. |
| 🛖 Shed / Outbuilding | Conditional | city | Valuation-based where enforced. | Small sheds often over-the-counter where enforced. | Generally allowed | In unincorporated no-code areas a shed may need no building permit; zoning/setback still applies. Verify locally. Exempt: IRC R105.2 exempts detached accessory structures ≤120 sq ft. |
| 🪜 Basement Finish | Conditional | city | Valuation-based where enforced; includes trade permits. | Standard plan review where enforced. | Generally allowed | In no-code areas finishing a basement may not require a permit; egress/safety rules still apply by best practice. Exempt: Cosmetic finishing (paint, flooring) is exempt. |
| 🚗 Garage / Carport | Conditional | city | Valuation-based where enforced; includes trade permits. | New-structure plan review where enforced. | Generally allowed | Attached and detached garages require a full building permit where enforced; confirm with your city/county. Exempt: New detached structures over the IRC threshold require a permit where enforced. |
| ☀️ Rooftop Solar PV | Conditional | city | Building + electrical permits where enforced; fee set locally. | Issued with the building/electrical plan review where enforced. | Generally allowed | Wyoming has full-retail net metering (Wyo. Stat. § 37-14-101 et seq.); racking must be engineered for wind/snow. Residential solar is exempt from property tax (Wyo. Stat. § 39-11-105). Exempt: No size exemption; all rooftop PV requires permits where enforced. |
| 🌡️ HVAC Replacement | Conditional | city | Mechanical permit where enforced; fee set locally. | Trade permits often issued same-day where enforced. | Generally allowed | Plumbing and HVAC are local-only in Wyoming (no statewide license); equipment must meet efficiency standards where an energy code is adopted. Exempt: In-kind replacement in the same location may be exempt. |
| 🍳 Kitchen Remodel | Conditional | city | Valuation-based when structural/plumbing/electrical work is included, where enforced. | Standard review for permitted scopes. | Generally allowed | Where the energy code is triggered, efficiency requirements apply; cosmetic refreshes do not require a permit. Exempt: Cabinet/countertop swap in the same layout is exempt. |
| 🛁 Bathroom Remodel | Conditional | city | Valuation-based when plumbing is relocated, where enforced. | Standard review for permitted scopes. | Generally allowed | Ventilation to the exterior and GFCI protection are required; verify locally. Exempt: Fixture-for-fixture swap in place is often exempt. |
| 🏗️ Room Addition | Conditional | city | Valuation-based where enforced; includes trade permits. | Plan review 2–4 weeks where enforced. | Generally allowed | In no-code areas a new addition may not require a building permit; confirm with your city/county. Exempt: No exemption — any new conditioned footprint requires a permit where enforced. |
| 🪟 Window / Door Replacement | Conditional | city | Usually no fee for in-kind swap; permit needed if opening is enlarged, where enforced. | In-kind swaps typically need no review. | Generally allowed | Replacement products should meet energy-code requirements where the local code is triggered. Exempt: Same-size, in-kind replacement is generally exempt. |
| 🏘️ Roof Replacement | Conditional | city | Often over-the-counter or exempt for same-footprint re-roof, where enforced. | Re-roof can be same-day where enforced. | Generally allowed | Cheyenne snow loads are significant; ice-shield/underlayment required. Verify locally. Exempt: Same-material, same-slope re-roof often exempt/over-the-counter. |
| 🅿️ Driveway / Parking Pad | Conditional | city | Building permit often not required; curb-cut/right-of-way work is separate. | Right-of-way permits reviewed by the city/utility. | Generally allowed | A separate right-of-way permit is usually needed to cut the curb or connect to the street. Exempt: Replacing a driveway in the same footprint (no new curb cut) is generally exempt. |
| 🏊 Swimming Pool / Spa | Conditional | city | Valuation-based; includes barrier/fencing and electrical bonding review, where enforced. | Plan review; barrier inspection required before filling, where enforced. | Generally allowed | Wyoming follows the IRC/ISPSC swimming-pool barrier requirements; verify with the building department. Exempt: No exemption — all permanent pools/spas require a permit where enforced. |
| 🧱 Retaining Wall | Conditional | city | Valuation-based when over the height threshold, where enforced. | Over-threshold walls need plan review where enforced. | Generally allowed | Walls in hillside or drainage-path areas have stricter rules; verify with the building department. Exempt: Walls ≤4 ft above grade and not supporting a surcharge are exempt under IRC R105.2. |
| 💥 Demolition / Teardown | Permit required | city | Demolition permit fee set by the city where a building department enforces; verify locally. | — | Generally allowed | A full teardown or major structural demolition requires a demolition (building) permit where the city enforces a building code (e.g., Cheyenne). Structures built before 1978 may require an asbestos/lead-paint survey and abatement, and utility disconnects are typically required before teardown. Much unincorporated county land has no building permit at all. |
| 🚰 Septic System | Permit required | county | Small wastewater permit fee set by the county; verify locally. | — | Generally allowed | Small wastewater (septic) systems are permitted by the county (under Wyoming DEQ delegation) prior to installation, repair, or modification. A percolation test and site evaluation are required; Laramie County issues permits for Cheyenne. Systems over the county threshold or with surface discharge involve the Wyoming DEQ. |
| 🔌 EV Charger | Conditional | city | Electrical permit fee set by the city where enforced; verify locally. | — | Generally allowed | A home EV charging station normally requires an electrical permit for a dedicated 240V circuit and wall unit where a building department enforces (e.g., Cheyenne), under the NEC. Plug-in (cord-and-plug) Level 1 charging from an existing outlet may be exempt where code allows; a new dedicated circuit or hardwired unit requires a permit. |
| ⚡ Standby Generator | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city where enforced; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context) where a building department enforces. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
Frequently asked questions
Who issues building permits in Natrona County, Wyoming?
City of Casper issues building permits; unincorporated Natrona County may have no local building-permit requirement is the permitting authority for Natrona County. Permits are issued by the incorporated cities; the county handles only unincorporated areas. Start at the official portal linked above.
Do I go to the county or my city for a building permit in Natrona County?
Permits are issued by the incorporated cities; the county handles only unincorporated areas.
What home projects need a permit in Natrona County?
The same project types shown in the cheat-sheet above (ADU, deck, fence, shed, solar, and more) — rules follow Wyoming state law. Whether the county or your city issues it depends on your property's incorporation status.
How do I apply for a permit in Natrona County?
Use the official permit portal linked above. Most offices accept online submissions; have your plans, site information, and contractor details ready before applying.