Hi @JodieMarwick,
Welcome to Bunnings Workshop, it's great to have you here!
I'm going to try and think outside the box on this renovation, I suspect that you want to modernise your bathroom?
If you used moisture-proof plywood and there are coatings/membranes that can be applied to the plywood, I think this could work.
It would entail you having tools like a circular saw and all the usual hand tools.
Please do not use MDF board for this, it will suck up any moisture and expand like a sponge.
This is certainly do-able and if you had the know-how to use a router, you wouldn't need to have harsh, angular lines and instead had nice sweeping curves where things join together
What are your thoughts on this?
I would be more than willing to give you any advice you need to help out with a project like this, bathroom reno's are never easy because of the moisture involved, but I have done a couple of them myself and if I can help out at all, that would be great.
Cheers,
Mike T.