Hi Louise, We have kinda rearranged certain room openings, and all rooms has been gutted and now being erected with new walls. Thats the top level layout plan i have sent. The lower level has 2 more bedroom and laundry, bathroom (sidebyside) and a garage which was opening to media room (common lounge area) and I have thus converted this garage to a 5th bedroom. Not so much of floor space we have, so hence the only option was (as per amatuer thinking) to rearrange the walls, create empty unused space with storage area and so on and so forth.

It's not a simple debate between what you want/need more or less....understand that this a regulatory thing.........if you are dealing with a building permit then it's pretty cut & dry - as the BCA reads, a separate trough is technically required to consitute a laundry....happy to be corrected in my interpretation in this regard but we have had to deal with this exact issue on a few occasions....... But if you are doing just an under the radar laundry reno/refit (no permit) then potentially you can get away with none, but you'll of course need to practically connect the washer into the drainage somehow, which still requires an isolated trap set-up, that technically will be illegal. No you can't just connect straight into a sewer waste as if the connection fails and their is no water trap it would be hazardous (not to mention unpleasant) to have exposed sewer gas. If it's in a kitchen an can connect a washer to a sink waste (similar) to the dishwasher) then arguably that could be passed. The easiest way is to fit a small trough next to the washer that even if you develop a cover for so you can use the area as bench space. It then keeps flexibility and everything above board/compliant for future resale.....

custom made vanity and wall cabinets should only be needed if you have awkward sizes as an off the shelf cabinet allows you to see and touch the product and is often much more economical than custom made ...unless you need to keep some special supplies (eg 24 pack of toilet rolls?) i suggest that a base cabinet need only be 450-500 deep which is plenty for folded towels and drawers and the in wall cabinet about 150mm deep (including most of the cabinet inside the wall and only a small frame for doors and mirrors projecting out) but the in wall cabinet may depend on existing wall studs and electrical wiring so think about what you would put inside the cabinets and only have enough inside cabinet space for those items (maximum toilet roll or fat shampoo bottle about 120mm...in small bathrooms the extra floor space makes drying and dresssing much more comfortable and by rotating the shower in the family bathroom there would be less wet floor in the walkway and if the vanity in the ensuite is away from the corner you can allow space for a handtowel and/or a very convenient space to hang a hair dryer ...

Thanks for all your comments. I'm adding a photo. Follow-up to some of the comments: tub is in good working order; cost of removal not a factor as I do the work myself; wife wants to replace with rattan etagere with plants & ceramics on shelves. Again, key question: is tub appropriate in powder room off living room, character or not?