Key facts
| City | Hot tub permit trigger | Cold plunge | Who can do the wiring | Power price used here | Draining |
|---|---|---|---|---|---|
| Columbus, OH | Any structure able to hold more than 24 in of water, hot tubs and spas included; 48 in barrier unless ASTM F 1346 cover; not in front or required side yard; outlets no closer than 6 ft | Same 24 in test on the tub's capable depth | Homeowner, only in an existing single family home they live in and for their own work; otherwise licensed contractor | Varies by utility and supplier | Sanitary sewer, or owner's lawn or garden; never off the property otherwise |
| Milwaukee, WI | Pools need a permit (414-286-3280); spas not listed separately, so ask | Any new outlet is electrical work | Licensed contractor for all electrical work (414-286-2532) | We Energies Rg1 about 19.593 cents with fuel and environmental charges; Rg2 10.028 off peak, 30.084 on peak | Wisconsin DNR: own vegetated yard after dechlorinating, or household sanitary drain if allowed; not to storm sewer |
| Louisville, KY | Pool/Spa Residential permit in the Metro Business Portal; owners may obtain without contractor license | New wiring needs a permit | Separate electrical permit | LG&E RS 11.372 cents base; RTOD 9.185 off peak, 19.180 on peak (500 customer cap) | MSD: no draining within 48 hours after rain; 0.1 ppm chlorine, pH 6 to 8; grass or sanitary cleanout; 30 gpm max |
| Kansas City, MO | Not exempt unless a prefabricated pool under 24 in deep, above grade, 5,000 gal or less | No mechanical permit for self contained chillers at 1 hp or less or 10 lb refrigerant or less | Plugging approved portable equipment into an existing approved receptacle is exempt; new circuits are not | Missouri EIA statewide average 16.02 cents (August 2026) | Ask Kansas City Water Services |
Sources: Columbus Building and Zoning Services FAQ; Milwaukee DNS permit checklist; We Energies 2026 electric rates; Wisconsin DNR residential pool water practices; Louisville Metro, Get a Permit; LG&E electric tariff, Kentucky PSC; Louisville MSD, Safe Pool Draining Tips; Kansas City, Building Permit Exempt Work; EIA Electric Power Monthly, Table 5.6.A. All checked October 25, 2026.
Columbus: the 24 inch definition
Columbus Building and Zoning Services defines a swimming pool as any structure capable of a water depth greater than 24 inches, including hot tubs and spas, and requires a building permit for any such pool. The word capable matters: a plunge tub 30 inches deep is covered even if you fill it to 22 inches, so use the inside depth on the spec sheet. A 48 inch barrier is required, but spas and hot tubs with a safety cover complying with ASTM F 1346 are exempt from it. A pool may not sit in a front yard or a required side yard, no receptacle may be closer than 6 feet to the water, and the site plan must show outlets within 20 feet and the electric service line.
The electrical permit is pulled by the homeowner or a licensed electrical contractor, and a homeowner may pull permits only for an existing single family home they live in, for work they do themselves. Drain water goes to the sanitary sewer or onto the owner's lawn or garden, and must not leave the property except through the sanitary sewer. Building and Zoning Services is at 111 North Front Street, 614-645-7433, with plan review for 1 to 3 family work taking about a week.
Milwaukee: licensed electricians and a choice of peak windows
Milwaukee's Department of Neighborhood Services checklist says all electrical work needs a permit and a licensed contractor, and that swimming pools need a permit. Hot tubs are not listed separately, so call the pool line at 414-286-3280 with the model. Decks need a permit and patios do not, which favors a pad over a new deck.
We Energies' 2026 residential Rg1 rate is 19.342 cents per kWh plus 0.199 cents fuel cost and 0.052 cents environmental control, about 19.593 cents, plus about 49 cents a day. The Rg2 time of use rate charges 10.028 cents off peak and 30.084 cents on peak, and customers choose one of four 12 hour peak windows: 7 a.m. to 7 p.m., 8 to 8, 9 to 9, or 10 a.m. to 10 p.m. For draining, Wisconsin DNR recommends letting water sit 6 to 8 hours in sun, bringing pH near 7, and draining slowly over a vegetated area on your own property, and strongly recommends against draining directly into a storm sewer. A household drain to the sanitary sewer is an option where the municipality allows it.
Louisville: owner permits, cheap power and strict drain timing
Louisville Metro's permit page lists a Pool/Spa Residential permit, obtained through the Metro Business Portal, and states that the listed building permits can be applied for without a contractor license if you own the property. Electrical work is a separate trade permit.
LG&E's Rate RS, effective with service on and after August 14, 2026, charges 48 cents a day and 11.372 cents per kWh base energy, with fuel adjustment and other clauses added on the bill. The RTOD-Energy rate charges 9.185 cents off peak and 19.180 cents on peak; on peak is weekdays 1 to 5 p.m. from April through October and weekdays 6 to 10 a.m. and 6 to 10 p.m. from November through March. The tariff caps RTOD-Energy and RTOD-Demand together at 500 customers. Louisville MSD's draining guidance is the most detailed of the four cities: not during or within 48 hours after rain, at least 10 days after chemical treatment, about 0.1 ppm total chlorine and pH 6 to 8, to a grassy area or a sanitary sewer cleanout, at no more than 30 gallons per minute (MSD 502-540-6000).
Kansas City: two exemptions that matter
Kansas City's exempt work list, from Section 18-16, starts with the rule that permits are required for most building, electrical, plumbing, heating and ventilating work. The pool exemption covers only prefabricated pools accessory to a one or two family home that are less than 24 inches deep, with walls entirely above grade, and no more than 5,000 gallons. A full size spa does not fit. A low soaking style cold plunge might.
The mechanical exemption is good news for plunges: no mechanical permit is required for any self contained refrigeration system with 10 pounds or less of refrigerant, or actuated by motors of 1 horsepower or less. The Cold Life lists its Pro Curve chiller at 3/4 horsepower. On the electrical side, connecting approved portable equipment to approved permanently installed receptacles is exempt, so a plug in plunge or a 120 volt spa on an existing suitable outlet needs no electrical permit; a new circuit does. Decks no more than 30 inches above grade, not over a basement or story, and patios on existing grade are exempt from building permits. Exempt work must still meet the zoning and building codes. Questions: 816-513-1511.
Worked costs: one chiller, one heater
A 450 watt chiller, the rating Penguin Chillers lists for its Premium Acrylic plunge, running six hours a day uses about 81 kWh a month. A 4 kW spa heater, the rating AquaRest lists for the Discover Premium 600 on 240 volts, uses 4 kWh per hour of heating. Base or all in energy only, before fixed charges and any riders noted:
| City and rate | Cents per kWh | Chiller, per month | 4 kW heater, per hour |
|---|---|---|---|
| Milwaukee, We Energies Rg1 (with fuel and environmental charges) | 19.593 | $15.87 | $0.78 |
| Milwaukee, Rg2 off peak (with fuel and environmental charges) | 10.279 | $8.33 | $0.41 |
| Louisville, LG&E RS base | 11.372 | $9.21 | $0.45 |
| Louisville, LG&E RTOD off peak base | 9.185 | $7.44 | $0.37 |
| Kansas City, Missouri EIA average | 16.02 | $12.98 | $0.64 |
Columbus is left out of the table on purpose: its price depends on your utility and on any generation supplier you have chosen, so multiply 81 kWh or 4 kWh by the all in price on your own bill. Real chiller run time can be far more than six hours on a sunny July day; NOAA normals put the average July high at 85.5°F in Columbus, 82.2°F in Milwaukee, 88.5°F in Louisville and 87.2°F in Kansas City. All four cities see January lows under 28°F, so freeze protection for spa and chiller plumbing matters everywhere here.
Related guides
- Fire pit rules in Columbus, Milwaukee, Louisville and Kansas City
- Cold plunge permits and wiring in Dallas, Chicago, Austin, Miami, San Diego and Boston
- Cold plunge chiller power and cost to run
- 120V plug and play vs 240V hot tubs
- Hot tub permit rules by city
Frequently asked questions
Is a hot tub a swimming pool in Columbus, Ohio?
Yes. Columbus Building and Zoning Services defines a swimming pool as any structure capable of a water depth greater than 24 inches, including hot tubs and spas, and requires a building permit for it. Spas with a safety cover complying with ASTM F 1346 are exempt from the 48 inch barrier.
Does Kansas City, Missouri exempt hot tubs from a building permit?
Not on its published exempt list. Section 18-16 exempts prefabricated pools at one and two family homes only when they are less than 24 inches deep, with walls entirely above grade, and no more than 5,000 gallons.
Does a cold plunge chiller need a mechanical permit in Kansas City?
Not if it is a self contained refrigeration system with 10 pounds or less of refrigerant, or actuated by motors of 1 horsepower or less, per Section 18-16.
Can I wire my own hot tub in Milwaukee?
Milwaukee's DNS permit checklist says all electrical work needs a permit and a licensed contractor.
Can I pull my own hot tub permit in Louisville?
Louisville Metro lists a Pool/Spa Residential permit in the Metro Business Portal and says the listed residential building permits can be obtained without a contractor license if you own the property. Electrical work is a separate permit.
What does a cold plunge chiller cost to run in these cities?
For a 450 watt chiller at six hours a day, about 81 kWh a month: about $15.87 on We Energies Rg1 in Milwaukee, about $9.21 in base energy on LG&E Rate RS in Louisville, and about $12.98 at Missouri's statewide average of 16.02 cents in Kansas City. Columbus prices depend on your utility and supplier.
How should I drain a hot tub in Louisville?
Louisville MSD says not during or within 48 hours after rain, after at least 10 days without chemical treatment, at about 0.1 ppm chlorine and pH 6 to 8, to grass or a sanitary cleanout, at no more than 30 gallons per minute.
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