Not every idea touted as universal design makes sense.
The walk-in bathtub is one example. Do you know the one I’m talking about? The picture in the advertisement shows a young 60-ish and happy guy or gal in their bathrobe stepping in or out of the tub through a door, pleased with the ease with which they can once again take a bath.
Sure, navigating a bathtub side-wall can be difficult. Issues of strength and balance make it treacherous. Falling, as a result, is not uncommon. A doorway through the sidewall of the tub isn’t a bad solution, it’s just that while it solves one problem, it raises another … burr, cold! The advertisement doesn’t show the user sitting in the tub waiting for it to fill; this bathtub design can’t have water in it with the door open! It also doesn’t show the user sitting in the tub waiting for it to empty. Finally, it doesn’t show how it helps a person who might be transferring into the tub from a seated position. Why? Because the seated user, probably someone who uses a wheel chair, needs a raised bathtub if this door in the sidewall is going to work.
Conclusion: replacing your bathtub with a walk-in is expensive and will not have you smiling like those people in the advertisement.
Solution #1: Keep your existing tub; make other modifications that will ease its use. Add grab bars where they can be grabbed while entering and exiting the tub. Consider the ceiling-to-floor “fireman pole” grab bars that can be placed just outside the tub. Remove obstacles such as shower doors and their tracks (replace with a shower curtain). Put a transfer seat next to the tub. Put a seat in the tub – maybe the kind that electrically raises and lowers.
Solution #2: Ship the tub; replace with roll-in shower. Taking baths are more physically challenging than showers. Thus, when only one is possible, favor the shower. Have a no-threshold entry and a seat.
Solution #3: Get the walk-in tub, but not just any model, get the one that is elevated so the bottom of the seat is at the same height as a wheelchair. And finally, ask for fast fill and fast drain models thereby minimizing the “brrr” factor.