Spas, Hot Tubs and Water Features in Chattanooga
Most of these are rough-in decisions, not accessories. Here is what each one costs in the Tennessee dealer survey, and what heating actually runs per month in this climate.
Decide these before the plumbing goes in
An attached spa shares the pool's equipment pad, plumbing and controls. It is a construction decision made at rough-in, and it cannot be sensibly retrofitted to a gunite shell later — the shell and deck would have to be cut and the pad re-plumbed.
The same logic applies in lighter form to waterfalls, bubblers and raised walls: the lines and the structure either go in with the shell or they do not go in cheaply.
What each addition costs
| Addition | Tennessee survey average | Notes |
|---|---|---|
| Integrated spa | About $20,700 | Shares the pool's equipment pad. Designed in, not added on. |
| Waterfall | About $3,138 | Plumbed off the pool's circulation, so it is a rough-in decision. |
| Heater | About $5,881 | The unit itself. Running cost is the bigger long-run number. |
| Automation | About $5,906 | Controls for pump, heater, lights and features from one panel. |
| UV sanitation | About $2,694 | Reduces chemical demand; runs alongside the filter. |
| Automatic cover | About $19,769 | Heat retention and a physical barrier over the water. |
All six figures come from the Tennessee dealer survey. They are market averages for the state, not our quote.
Heating economics in a 46-day summer
Heat pump
Roughly $50–$100 a month to run. Extends the season by two to three months.
Gas heater
Roughly $300–$500 a month to run. Can hold temperature year-round.
Chattanooga's frost window runs from a median last spring frost of April 4 to a first fall frost of October 31. Unheated, the comfortable swimming stretch is narrower than that on both ends.
So the heat-pump case here is a shoulder-season case: April and May at the front, September and October at the back. Gas buys January, at five to ten times the monthly cost. Pair either one with an automatic cover and the heat you paid for stays in the water overnight.
Spa and feature questions
- Is a heat pump or gas heater right for this climate?
- For most Chattanooga backyards, a heat pump. It runs roughly $50 to $100 a month and adds two to three months of season on either side of summer, which is exactly the shoulder-season problem here. Gas costs $300 to $500 a month and holds temperature year-round — that is a different purchase, for people who genuinely swim in January.
- Can a spa be added to an existing pool?
- Not sensibly on a finished gunite shell. An attached spa shares the pool's equipment pad, plumbing and controls, so it is designed in at rough-in, not bolted on later. Retrofitting means cutting the shell and deck and re-plumbing the pad. A freestanding hot tub set on the deck is the practical alternative.
Get the rough-in decisions right
Send the address and what you want the water to do, and you'll find out what the spa tie-in, the heater choice and the run-time economics look like in this climate.