Hi Sofia I definitely think brick lay would work better on the walls in the bathroom purely because you have a 30x30 on the floor and a 30x60 on the wall. You will find the tiles could look out of place trying to stack them. It would be a different matter if they did not share 1 or more dimension. Perhaps in the ensuite, consider doing something like this: [https://www.houzz.com.au/photos/what-architecture-beirutful-house-eclectic-patio-london-phvw-vp~14310278[(https://www.houzz.com.au/photos/what-architecture-beirutful-house-eclectic-patio-london-phvw-vp~14310278) Tile the floor and half way up the back wall with the "floor tiles", perhaps a tile or 2 above the vanity unit and then continue with the white tiles to the ceiling. You could hang your mirror so it covered about 1/4 of the "floor tile" and 3/4 of the white above the centre of the sink. In the main bathroom consider something like this: [https://www.houzz.com.au/photos/victorian-dream-bathroom-victorian-bathroom-london-phvw-vp~39122647[(https://www.houzz.com.au/photos/victorian-dream-bathroom-victorian-bathroom-london-phvw-vp~39122647) Tiling the back wall to the shower in the "floor tile" to the ceiling with the white tiles behind the loo to the ceiling. Alternatively, tiling the entire back wall with the "floor tiles". The first option may make the bathroom feel smaller if the shower takes up more than 1/3 of the back wall. Doing the two different options would give the bathrooms continuity, but also some individuality. I hope this helps. Look forward to perhaps seeing the outcome. James

because the water could seep through the joints between the new tiles and sit between the two layers and affect the seal and also raise the height of the floor and affect the slope to the waste outlets..but, why do you want to retile if you're not using the bathroom??...for immediate resale consider bathroom wall to wall bathroom carpet, new wall paint, new vanity, taps and light fittings which should also be cheaper than tiling over the top and, if it's not allowed by the body corporate, it will be a risk to future sales as it should not satisfy a proper building inspection

Have you priced having the whole lot re waterproofed and tiled? You are already doing the hardest section, it may not be that much more to do the lot. Otherwise agree with above match to the white tiles in the rest of the bathroom. But it will always look like a repair.

Tile selection can have a big impact on the cost of your bathroom reno. The cost of the tiles per sqm is one thing, but did you know that most tilers charge different rates for the "Type" of tile laid large format and or vitrified tiles will cost more to install These are a few hard and fast rules we give our clients when they are selecting tiles for a bathroom renovation 1 - opt for darker tiles and darker grout for the floor - as a wet area light coloured tiles on the ground are harder to keep clean 2 - If you are opting for a feature tile - let it be the hero. That means make the rest of the tiles plain - large format subway tiles give you enough texture without detracting from the feature 3 - always opt for square tiles on the ground - trying to get the correct falls using rectangular tiles will mean you will have extra cuts and the floor will look a mess. The second reason we opt for square format for the floor is because of subway tiles You see, back when everyone was opting for square tiles on walls, it was easy to install square on the floor and get all the grout lines to match. Now most people are opting for subway tiles, you can never get all the grout lines to match, therefore installing square means you dont have to match grout lines as they are different format. If you are installing your subway tiles vertically, then there is a chance you will still be able to get all grout lines to match if you have selected the same sized square format tile hope this makes sense I have added a link to a blog that explains more about tile selection