How small is the existing bath and what is under it? The slope needed for a proper zero barrier shower is often actually prohibitive in a existing space.

Thanks for feedback- the room is 1.25 X 3.5 metres (4 X 11 feet approximately).

Would you worry about getting cold while showering especially during winter ?

We had one in the house we bought. We just replaced it with a steam shower, which is about as opposite as you can get. Can be cold. You have to stay directly in the water and any movement out of that is unpleasant. We love treating colds and things with steam, which is pretty impossible to do compared to a standard shower. The biggest issue was the adjacent wall wasn’t tiled, and there was no threshold, so it eventually started to create a mold issue on the baseboard from water splashing out. There was a long linear drain ditch and another raised tiled part before the wall. We are staying in a rental right now (long story), and it has no shower door and really tall ceilings, and it’s even more cold and uncomfortable. Personally, I would not recommend.

Old shower for reference. The mold was pretty bad on the baseboard on the right

Thanks to all for all your helpful feedback

When they replaced my aunt's tub with a shower the lack of a threshold leaked into the bathroom. so the barrier free design caused a slipping hazzard.