Thanks :) Yeah decided to go with tile. So sand cement is ok over existing tiles if I prep them first? Only problem is, the new pad can only be about 30mm at it's thickest (leaving up to 15mm for tiles) otherwise it'll end up being higher than the hallway floor. So I either need to make the fall shallower or not bother with the waste and make it all level. If I made it level, could I use levelling compound at that thickness or would deck mud/sand cement be the best option? Also, should I be putting in mesh for strength? (I know I should (and will) ask the local hardware what they suggest, but it's great to have suggestions from the Houzz community also)

I love your post, there is a blueprint and you are giving out details and whishes witch is making it easier for all of us to help you and your family. This floorplans reminds me a bit about my uncles house. here are some of my thoughs witch you may/or may not use. I am not sure about the NSEV directions which have a major influence in building a house. Parenting so many kids also influence the house and the lifestyle in the home. I would maybe add, or rebuild an ancle to the house prevent from wind on the terrace. Commidded as you sound i would go all in with all of your wishes. I think a big master bathroom is needed to be used as a place to relax with so much to look after. I dont now if your coing to use the door in the lundry room or in the pantry most. I thinks its best to have your garrage entry close to the pantry and kitchen. A open kitchen is also a big decision when you have so many young kids. I would maybe add a breakfast area in the kitchen. SOme other things to consider is maybe the entry and the long hall way. I think you and your family might be a bit tired of the loong hallway. if possible i would switch the entry and the office. to make the entry in to the livingroom, if le librarry is going to be used as a familyroom. A toilet should always be placed near an entry to the house. And an extra toilet is only for u to clean along the way.... I you are looking to expad the family i would maybe build a playroom in the middle of all the kids rooms. At my uncle ealier house theay had a combined office space, guest room, playroom to combind a space for all of the children and their friends to be in. As far as going to design in your home can also maybe influence the layout. I think wood floors or tiles depend on style. I Personally prefer laminet wood floors in the kitchen and entry, but you are to buy some lovely tiles now a day. Pleace ask for a new blueprint suggestion if you are up for some changes. good luck.

I agree with emily. if you want leave connections and/or a little extra room for what you don't want, but feel you may need for resale. I think the tub is a pretty important item. wet room not at all, and shower is give or take. i would prefer a big shower and a tub for soaking in, but I have always had the combo. I remember my mom built during big wet bar craze, she did not care for one. had space built, capped off connections and use as a closet. Now it is 35 years later, everyone wants to buy and tear down. Darned if you do, darned if you don't. i agree, I would also really like the separate toilet, we are not share everything people.

Maybe look beyond the footprint of existing bathroom. We renovated a bathroom where we were able to have a seperate large shower and keep the bath by incorporating a built in cupboard in a bedroom room adjacent to the bathroom. New Free standing storage in that room has resolved any issue with the loss of the built in.