I think this post would have been better suited to the Design Dilemma forum with some images! Hope the reno went well.

by "other options" i mean that you should consider all other options for locations of fixtures..there is already plumbing along each wall so swapping the location of shower and bath or vanity isn't as challenging as if there were no original plumbing in that area and if you plan to replace the fixtures and tiles rearranging the fixtures will only be a small percentage of the budget and it's a shame to limit the final result without at least considering other options..and although there is enough space to have the vanity hard up against the wall my suggestion is to have the vanity away from the wall to make it easier to clean and also because the small nook is an ideal space for hanging a hair dryer and with the luxury of so much space it will be easier to install a vanity away from the wall

without further input from HU-206141322, dimensions and wall materials we can't offer precise ideas. A basin fully or partially recessed into the wall is the best solution but depends on material used for the walls. The following suggests moving the door which could allow enough space for a small hand basin without recessing. But without more details hard to know

Unfortunately a cavity sliding door on the toilet won't work due to structural considerations. It would be a massive task to modify the existing wall to create a cavity. Anyway, I don't like them. Every house I've been in that had a cavity slider it sagged, and they are so hard to adjust when that happens. They are a great idea in theory, but I've not seen one work well in practice. I did consider a barn slider along the toilet side. Not sure what you mean by an 'inbuilt basin', Shirley. If you mean the type that sit over the toilet cistern, I looked at them and rejected because they are awkward to get at and use. In UK, they make units with an integrated basin next to the cistern and some are very stylish. Nothing like that available in Aus, sadly. I also wanted to ensure there was at least a small amount of cabinet space for toilet cleaner and cloth and spare toilet paper and a few personal conveniences. Where are you located, Julia Lesley? We are on the Sunshine Coast and finding it well nigh impossible to get building tradespeople to do anything at present. The renovator I mentioned above is booked up for 5 months!