Thanks for the advice Carolina and the example :) I had thought about tiling up to the 120cm mark the whole way round previously. At the time I was thinking about going with a plain white tile so that I could change the colour if I wanted to over time. Once I found the stone effect tile, I hadn't really reconsidered that as an option. I'm struggling to leave any walls completely free as I do want to tile anywhere that could get properly wet with kids around... I should have said in my original post that I'm putting quite a large mirror behind the sink unit and the sink unit will be behind the door when you walk in. I have mosaic behind the sink in the ensuite and really like the style but not sure if I'd get the benefit of the mosaic behind the sink in this room given the size of the unit and the mirror. I'll probably look to introduce some wooden accessories, a large print to the right of the window to balance out the off centre window and (if I don't kill it), some large leafy plants (just like your example) so that in itself might add some interest!!

These are the tile samples I have so far. On the left - small top dark grey, under that is a tile with faux stepped marble effect tiles that are more slate toned. Large tile to the right is the mandarin stone one (v expensive, lol) The walnut in the middle I love the pattern but it’s not as rich a colour as I wanted and I can’t find anything else online in an American walnut style tile. The bottom tile is a v v pale grey with similar pattern to the mandarin stone one. How would you work these tiles together? Walnut floor and sink unit and dark grey all over the walls? Just the patterned grey on the back of the shower wall and sink area and plain grey on other walls?? :0/

If you love marble, you could try a porcelain marble in Calacatta Gold. It has a brown/gold vein. For example: https://www.wickes.co.uk/Wickes-Boutique-Calacatta-Gold-Lux-Glazed-Porcelain-Wall+Floor-Tile---600-x-600mm/p/191545 or https://totaltiles.co.uk/calacatta-gold-gloss-marble-effect-porcelain-floor-tile.html

LVT is generally fine up to 27 degrees with UFH but you’d need to check the relevant make etc. A warm stone effect could work particularly if you have the room to add accessories to bring in more warmth? I don’t think a chevron wood effect would give a nautical feel and the pattern gives the effect of texture. I think any wood would work though, just avoid accessorising with anything nautical if that’s not the look you want! Do you also want to avoid pattern in the shape of the tile as opposed to a print on the tile?