@Alasdair28 Hot tubs are lovely and do add value. However, they use chemicals. They require energy to remain heated and water replenishment due to spillage and use.
We have hot tubs. To get around the chemical use aspect, we empty the hot tub between guests, scrub it out and refill with fresh mountain water. We are on a well, so our water is "free" and we use the wastewater from emptying the tub for watering the garden and lawn.
There is no getting around the electric use. It is not economical electrically to turn the hot tub off between guests (more energy used in reheating), and most guests will crank up the heat to the highest setting and leave it there and forget to put the cover back on....
Good luck with your decision.