Nice blank canvas to work on!

Not ideal to open the door and look straight at the WC but you could move the vanity across to where the door has been bricked up.

yes we are - the third pic from the top is our bathroom

If you are looking to use a walk in shower on an existing slab then it will be a bit tricky and expensive to get the grades and fall right. It looks like your existing shower waste is in the back left corner of the shower recess, so unless you are putting another waste through the slab this will need to be the lowest point. Make sure you are aware of the threshold height where the tiles meet the bathroom door. You should seek engineering advice if you are removing the top of the slab in the shower recess to get enough slope in the tiles to drain properly.

For the circulation width between shower and vanity I don't like to go below 700mm, but prefer more. The narrower the width the harder it will be for older people with walkers or canes, as well as supervising young kids when doing toilet training.

If that is a towel rail near the walk in opening to the shower then you will have wet towels before you step out of the shower!

Best of luck with you bathroom renovation,

Dr Retro

Is the opening to the shower from the end or the side? Also is that a freestanding bath squeezed into the corner. If it is it will be a nightmare to keep clean.

Hi - shower screen will be from the end wall. It is a wall facing bath (drawing tool doesn't have one of these in it so had to select a freestanding for diagram). The bath will be 100mm from side wall - so a little tricky but I will be able to get the vacuum hose down there!

It's a little unconventional badobbs, but have you considered a toilet with in-built basin and tap - these are very sustainable (although not for everyone!) and are perfect for tight spaces. https://specify.caroma.com.au/products/toilet-suites/profile/profile-5-toilet-suite-deluxe-with-integrated-hand-basin. 

To answer your question, usually you need min 800-900mm or so for a fixed panel for a shower, however normally walk-in open showers are located perpendicular to a room, so that splashes and wet floors are contained to one end. Think of when you drop the shower head and it sprays water everywhere! In your case I would advise selecting a well made frameless hinged door - so you can still have a walk-in effect but a bit more protection from water spraying out everywhere. Try Reece; https://www.reece.com.au/assets/brands/244000/custom-glass-brochure-v1.pdf

The vanity depth is going to be the issue here, usually we advise min 800-850mm clearance (although can go down to 700 as per Dr Retro House Calls) and can see from the plan that with an 800 bath and 700 clearance you only have 250 depth for your vanity when it's near the bath. You could get a vanity made up at 250mm deep with a semi-inset deeper basin centrally - that way you can make the vanity a little longer but with a workable basin. https://specify.caroma.com.au/products/basins/luna/contemporary-luna-semi-recessed-basin-without-tap-landing

Good Luck!

Thanks Dr Retro House Calls and Mcmahon and Nerlich for all your advice. We too have been thinking of a semi recessed sink Caroma Urbane to minimise vanity depth. This is the family bathroom so want a decent size sink for my two teenage children. I think I might have to go with keeping the shower footprint as it was, so a totally frameless door could be an option.

As another option I have been thinking that I could move the bath into the master suite that we are also renovating. I will sketch up a floor plan and post shortly.

That would be a great idea -move the bath into the master suite. Having a large walk in shower, toilet and basin in this room will ensure teens and others have room to move. Most baths are only just dusted nowadays.

Have you tried a walk-in shower? Some of the ones I've used in rented holiday houses, I ended up wiping the floor after each shower. This effect is probably worse if it's tight dimensions. I'd go for a frameless shower with a door any day. If you've got room to put the bath in the ensuite, that would certainly free up space in this bathroom.

Those toilets with basins on top totally gross me out. The aerosols! Poop and wee spray all over the basin and the tap because not many people close the lid of the toilet. Besides, it is a bathroom, you would not want to clean your teeth in one of those things unless you were desperate.