Hi Jen, good idea re the laundry - it would nicely "segregate" that functional space and open up all the rest as bathroom space. If you go that route, just check with a plumber that you don't cause any knock on issues with running a soil pipe from the back of the WC to the main soil stack (you really don't want those issues!!), and then make sure you do it in a way that doesn't lose light from that window. Regarding custom mirrors - the cheapest way is to get a local glazier to quote to make and install. Assuming it is just a single plain sheet you are looking for, the cost should not be too bad at all. Definitely get the glazier to install - it pays to leave the risk on their side, and they are experienced in handling the material. I've had a few bespoke glass splashbacks go "pop" on me, and there are few worse feelings... For what is a relatively piece of glass, make sure that there are no access issues to get it into the room (awkward bends round stairs or the like), or consider doing it in a couple of pieces. And if you are concerned about getting the best price, ask a couple of people to quote and look online too. And don't be afraid to haggle nicely - any glazier will try and squeeze a little extra margin if they can, so try and get it back! Try the online pricing tool at mirrorfit.co.uk for a quick feel of cost, or any of the other tools online.

vanity is full cabinet on 3" legs. using your pic, the right hand side is a full floor to ceiling wall and the left hand side is a half wall next to a glass enclosed shower. the half wall height next to the shower is 40" tall thus that height reference. remodeler plan is to tile from floor up to the 40" mark and all the way around all 3 walls to provide decorative backdrop since the vanity isn't as wide or as tall as the alcove. what I am unclear on is whether it's standard practice to tile behind a full cabinet vanity or not? remodeler suggests tiling the entire alcove in the event we have to replace the vanity for any reason, that way we don't have to try and find/match tile for any different exposures. my second question is since the tile is a textured pencil tile and the vanity doesn't have a backsplash (simply flat surface marble top) - remodeler suggests tiling fulll alcove first and then mounting vanity to back wall and caulking the vanity to the textured tile. this approach would use the textured tile as the backsplash (6" of the tile will be showing above vanity).

@activebuilderslondonltd think it’s probably going to have to be the whole wall which I’m not opposed to as think it shows the full beauty of the tiles and will be lit by down lights. No I tried endless trying to source off cuts last year to numerous companies, all came back with the same response as they didn’t have off cut availability hence saying I needed to source whole slab. This was the image that made us consider the other suggestion. Thanks for your advice, appreciated.

Sorry - only just seen this ! Needs a site survey, by someone with plumbing knowledge, I agree - and then a good bit of planning to get all of your boxes ticked. Most high end en-suites that I’m involved with the design of have a separate built in loo and basin ( with extractor fan) . Then a shower area ( with another extractor fan ) , bath and big vanity with storage with shaver /tooth brush sockets . If it’s a really big room then an area away from the water areas for hairdryer and makeup etc although this often gets incorporated into a dressing room area that’s often next to en-suite .