Key facts
| City | Small shed exemption | Heater wiring |
|---|---|---|
| Anchorage, AK | Up to 200 sq ft for sheds, playhouses and similar uses | Electrical permit and inspections; state owner exclusion with inspection |
| Honolulu, HI | Up to 120 sq ft aggregate | State licensed contractors only |
| Bismarck, ND | Permit above 120 sq ft; zoning still applies below | State self wiring: own and occupy, permission number first |
| Fargo, ND | None listed: permits for any new construction | Permits for electrical projects; same state self wiring rule |
| Charleston, WV | None: storage buildings and playhouses need a permit | Electrical permit; owner license exemption (29-3B-3) |
| Cheyenne, WY | Under 200 sq ft | State Home Owner Wiring permit, $50 fee waived with paid inspection |
Sources: Anchorage Handout A and residential inspections; AS 08.40.190; Honolulu building permit FAQ; Bismarck accessory buildings; Fargo Inspections FAQ; North Dakota self wiring requirements; Charleston 311 and Building Department permits; W. Va. Code 29-3B-3; Cheyenne building FAQ; Wyoming wiring permits.
The 200 square foot cities: Anchorage and Cheyenne
Anchorage's Handout A exempts one story detached accessory buildings used as tool and storage sheds, playhouses and similar uses up to 200 square feet. The same handout says the exemption does not waive other code, land use, setback or licensing requirements, and that electrical, plumbing and mechanical permits may still be required. Anchorage's residential inspection page lists rough inspections before work is concealed and a final at completion. Cheyenne's FAQ says detached sheds under 200 square feet need no building permit, while electrical, plumbing and HVAC systems need permits; the Building Department is at 307-637-6265. Whether a heated sauna counts as a similar use to a shed is a question for each city, so ask before you order.
The 120 square foot cities: Honolulu and Bismarck
Honolulu's Department of Planning and Permitting says Chapter 18 of the Revised Ordinances exempts one story detached tool and storage sheds, playhouses and similar uses only when the aggregate floor area is 120 square feet or less. Aggregate is the key word: existing sheds count. The same FAQ says all electrical work must be performed by contractors licensed by the State of Hawaii. Bismarck's accessory building handout requires a building permit above 120 square feet and says smaller buildings must still meet zoning rules for setbacks and height.
Cities that permit small buildings: Fargo and Charleston
Fargo's Inspections FAQ says permits are required for any new construction, addition, remodeling or structural alteration and for mechanical, electrical and plumbing projects; only flat work such as a bare patio or slab skips a permit. Charleston's 311 knowledge base says decks, patios, carports, playhouses and storage buildings need a permit, and Planning approval may also be needed. Applications go to the Permit Coordinator at 915 Quarrier Street, Suite 5.
Wiring the heater
An 8 kW heater such as Harvia's Spirit draws about 33.3 amps at 240 volts on 8 AWG supply wire. Alaska's AS 08.40.190(b)(3) excludes electrical work on residential property owned by the installer or immediate family and not intended for sale, but subsection (c) keeps that work subject to inspection. North Dakota's self wiring handout says you must both own and occupy the residence and call the state electrical inspector or the State Electrical Board for a permission number before starting. West Virginia's 29-3B-3(a)(1) exempts work on property owned or leased by you or your immediate family. In Wyoming, the State Fire Marshal's Home Owner Wiring permit is applied for online, and its $50 fee is waived when an inspection is requested and paid. Honolulu requires a state licensed contractor.
Worked example: one sauna, six answers
The four person barrel saunas we sell run about 38 to 51 square feet. Take a 51 square foot model on a lot that already has an 80 square foot garden shed. In Honolulu, 80 + 51 = 131 square feet, over the 120 square foot aggregate limit, so the exemption no longer covers it. In Bismarck, the sauna alone is under 120 square feet, so no building permit, but setbacks and height still apply. In Anchorage and Cheyenne, it is under 200 square feet, so the building permit question turns on whether the city treats it like a shed. In Fargo and Charleston, plan on a building permit. In all six, the heater circuit needs an electrical permit.
Related guides
- Backyard sauna permits in Little Rock, Portland ME, Sioux Falls, Billings, Omaha and more
- Backyard sauna permits in Saint Paul, Pittsburgh, Rochester, Madison and more
- Can you wire your own sauna heater? Homeowner permit rules
- Sauna heater breaker and wire size
Frequently asked questions
Does a backyard sauna need a building permit in Anchorage?
Anchorage's Handout A exempts one story detached tool and storage sheds, playhouses and similar uses up to 200 square feet from a building permit, but says the exemption does not waive other code, land use, setback or licensing rules, and electrical permits may still be required. A heater circuit is electrical work, so plan on that permit.
Does my existing shed count toward Honolulu's 120 square foot limit?
Yes. Honolulu's building permit FAQ says the exemption for one story detached sheds, playhouses and similar uses applies only when the aggregate floor area is 120 square feet or less, so existing sheds count.
Can I wire my own sauna heater in Honolulu?
Honolulu's FAQ says all electrical and plumbing work must be performed by contractors licensed by the State of Hawaii under HRS Chapters 444 and 448E. Plan on a licensed electrician for the heater circuit.
When does Bismarck require a permit for a sauna building?
Bismarck requires a building permit for accessory buildings greater than 120 square feet. Smaller accessory buildings still have to meet zoning rules such as setbacks and height.
Does Charleston, West Virginia exempt small sheds?
No. Charleston's 311 knowledge base says a permit is needed for decks, patios, carports, playhouses and storage buildings, and Planning Department approval may also be needed.
Does Cheyenne need a permit for a sauna under 200 square feet?
Cheyenne's FAQ says detached sheds under 200 square feet need no building permit, but electrical work needs a permit. Wyoming homeowners can apply for a Home Owner Wiring permit through the State Fire Marshal portal; the $50 fee is waived when an inspection is requested and paid.
Can I wire a sauna heater myself in Alaska, North Dakota or West Virginia?
Each state has an owner rule with conditions. Alaska's AS 08.40.190(b)(3) excludes work on residential property the installer or immediate family owns and does not intend to sell, though excluded work is still subject to inspection. North Dakota requires that you own and occupy the residence and get a permission number before starting. West Virginia's 29-3B-3 exempts work on property you or your immediate family own or lease.
Keep reading
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