I do bathrooms every day of the week and I can tell you now that, If you really want a bath in that space and shower just do a shower over bath I noticed your shower was 800mm wide this is to small for a shower 900mm minimum. Forget the bifold doors put in a cavity slider or if this is not possible do a face of wall sliding door on the out side of the bathroom. If you really really want separate bath & shower move the toilet into the laundry. Get an 1800mm deep soaker bath and run it along the 2000mm wall run your shower along the 2100mm wall opposite the vanity. I take it your on a timber floor not a slab as moving a toilet on a slab can get costly.

the bathroom looks about 1800 x 2700 which is wide enough for a super wide walk in shower 1800 x 900) across the room and double handbasin (1500-1800x 500) along the old bath wall with mirror doored wall cabinets above the vanity and there should be plenty of wall space for towel railsconsider wall hung vanity to allow floor space under the vanity for waste bin, scales, slippers etc and makes the room look more spacious

subject to confirmation by a plumber your new layout should be ideal with just enough space for a stacked washer and dryer and skinny tub and wall shelf for the laundry (i'm assuming the old shower position also has taps and floor waste) and a 1500 wide vanity with storage for linen and mirror doored medicine cabinet but what is the triangular space?? there could be wall thickeness to use for stacked doors for the laundry instaed of the bifolds btw a floating (wall hung) vanity is usually more expensive, creates problems hiding the pipes and will lose valuable storage space for towels and lineni would expect a full reno with modest quality fixtures and tiles and no surprises to cost at least $20,000 but suggest that a bathroom company that could take responsibility for organising demolition, plumbing, carpentry, waterproofing, tiling electrical, painting and sourcing the tiles, taps, screens, lightfittings, tubs, doors etc may be worthwhile and save you trying to juggle the trades who are less likely to be dependable for a single customer although with available time you may be able to save some money by removing old tiles and carting away rubble and finding the tiles. taps, vanity etcs and having them ready on site but coordinating all the trades can be a problem especially if you don't have an alternative bathroom although it's always good to be on site to supervise the work and answer any last minute questions

Hi Me, It's been 10 months, I hope that you have sorted it out. I like the idea of keeping the toilet separate as it will increase not only the aesthetic but also the hygiene and privacy of the main bathroom. It might be better if you can convert the swing door into a cavity door, which will help you have more ample space for comfort. In case you don't want to keep the toilet in a completely separate area, just don’t want it to be easily seen, consider adding a half wall is another great option. If you want to have more detailed info about bathroom layout, we got some resources on our website that might be of help. Check out the following guide to have more ideas to design the best bathroom layout to serve your needs and satisfy your aesthetic preferences based on the size, shape and limitations of the room. https://fontaineind.com.au/useful-resources-for-renovations/what-is-the-best-bathroom-layout