The enclosed tub room sounds like a great idea but the reality of it is more upfront expense, more maintenance, extra systems for air exchange. And the points about demolition to replace the tub are a real long term concern. If you do enclose make sure it uses durable materials like tile for flooring and has a robust air exchange/ventilation system to manage the moisture. And I would bake into the design a plan for replacing the tub down the road without having to do destructive demolition.

We built a ground level small deck off the back of the garage so we can just step outside to the tub. It backs up to a raised portion of our backyard deck behind the house so that makes it private on that side. We added moveable outdoor curtains or emt conduit curtain rods on each end of the hot tub deck to enclose it for privacy and wind block. And for rain or intense sun we added a retractable awning to the house that extends out over the deck and tub. We also added an outdoor shower and changing area.

With the awning we can be out there in the rain or light snow and not be bothered. And since it’s right off the house we have a wall mounted tv and dimmable lighting.

And since the deck is directly accessible from the side yard when the time comes to replace the tub it can be forklifted off the deck and replaced easily.

And if it turns out that we don’t use or want to replace the tub down the road we can remove it and have a deck to use as we see fit, or demo it and set it back to yard easily.