I hope you don't mind... seeing the external pics I have a totally different idea! But don't worry I don't expect you to actually use it, and it's just a rough sketch. You don't need to extend the footprint at all in my opinion. based on the picture of the front of house your drawing is a bit out... the entry stair actually sits to the left of the front door I think. so there is a little more room there, but i'm not sure if its wide enough. So maybe there is enough room to put a hallway back in and create a master suite upstairs? The front deck becomes a private retreat and I put the bath out there! It's only accessible from the master and bed 4. If you don't need that many bedrooms maybe even leave the master and bed 4 combined and have a huuuuge master area. there's still the study downstairs that could also be a spare bedroom. I thought as the front deck is so private it could be really luxurious. The old kitchen becomes the walk-through robe and ensuite. The new kitchen goes straight under the old, and the kitchenette becomes the bathroom,accessible from the pool. the downstairs kitchen is connected to the dining and living, but the posts define the areas. The kitchen can have a halfwall with a servery-style opening between the posts, and will still have that connection. I didn't draw it in on the downstairs picture, but the entry needs to be pushed a little forward and then the stairs run up from the left corner and arrive where the original entry was upstairs. The downstairs living is accessed straight from the entry at front and opens onto the front patio, under the back deck becomes the back patio. I feel like you have less new to build and retain more of the original layout. in fact the upstairs bathroom is entirely intact.

Oklouise and Siriuskey and others thanks so much for input. I’ve attached the version we think works best, but would like to configure the other space as a semi ensuite with hall access also, maybe we need to include the corner storage space as I have shown to make it work. Siriuskey, I have taken your advice and removed internal angle walls for fireplace,tv and butlers pantry and have realigned the other small wall as mentioned. We will reconsider when we are at built stage, how to define the spaces...I am liking the idea of cured walls to soften the other angles. Just wondering if I could stretch the friendship and have one of you re draw the small bath room into that space as shown I would be very grateful.

@kiwimills I use the lounge a lot, so really not keen on eating into that space. The laundry I really only visit to put on a load of washing or grab the mop (robot vac does the rest) so wanted to pop it into an area where it's closer to the lines and in space that is not being used. Love the ideas though. @Kate yup. I think if you have space issues a dedicated laundry room seems very wasteful for most people. And wasn't there a building regulation that says you can't put them in kitchens in Australia as well? Makes sense to put them where the rest of the plumbing is. I was actually thinking of going for full height if possible to maximise space. Do you find that sliding doors impede your access or frustrate you accessing the laundry? Obviously compromises have to be made, but just wondering whether that ends up being an issue? @oklouise Thanks a heap! The layout of the house at the moment has a hinged laundry door leading to some steep (non-railed!) steps leading to the backyard. I rarely use it for anything except to get airflow into the house, but was wondering if it would be important to keep? Obviously it's about what I need at the moment, but am also considering resale value just in case.

the biggest challenge is the location of the windows and enlarging the ens without having to rearrange the plumbing too much and, unless you want a bath in the ens and separate toilets my suggestion moves walls to allow for more space while keeping a smaller study and good sized family bathroom, bigger ensuite and more biw .... the area around the flue could be an ideal storage space for an upstairs vacuum cleaner, luggage etc but you should consult a heating specialist to confirm safe ways to enclose the flue and accurate dimensions will depend on how you measure the size of the windows (ie the edge of the window frame or the outside edge of the architraves?) and thickness of old and new walls but something like this could be worth considering