plans are so much easier to read when loaded this way and there's almost nothing i would want to change except to have dual access to the guest bathroom from the laundry hall (easier to reach from outside through the laundry) and swop the guest toilet and shower for better wheelchair access ...otherwise you should be very happy with the plan, your new home should be gorgeous and functional

my suggestions include changing the staircase to have a halfway landing never winding steps, rearrange the kitchen, pantry and laundry, lose the biw and soffitts in the guest room and disguise the ens access door within the new MPR/guest room wardrobe, side access for understairs storage is much easier to use and, by the time you load and unload the laundry into a shute it would be quicker easier and cheaper to throw the washing down the stairs and save the space for more useful purposes ..pleased to see the good sized garage...cheapest rumpus, mancave and wet weather playroom with the addition of a few lockable storage cupboards and shelves...can't see the value in the extra hot water tap and gas outlet for the alfresco..rather extend paving across the back of the house and invest in a servery window to load dirty dishes directly into the kitchen for the dw and inevitably the wind blows smoke into the house so it's better to have a moveable barbq away from the walls and...upstairs hallway narrower to allow for extra steps, rearranged ens and wiw, avoid the void and use the space for a WIL or space for a baby's cot, dressing area, and/or leave the space open and invest in a gorgeous chest of drawers for linen and use the big WIL as a study nook with a separate small lounge and rearrange the bathroom with generous storage in the vanities, bigger shower and narrow freestanding bath...without all your dimensions some of my sizes are approximate but adding furniture helps understand the spaces much better and inside of wardrobes should always be at least 60cms plus the walls an doors and it appears that the plumbing access could be in the garage instead of the kitchen?

From a "passive solar design" point of view, everything is right. Rectangular home facing north/south. With north facing living rooms, rarely used rooms to the west. But one other thing to consider, plumbing. Locating it close together will lower building costs, & the wastage of water, waiting for hot water. So I'd consider swapping bedroom 4 for the western wet areas. Behind the kitchen is have the laundry, then bathroom, then linen, the bedroom furthest to the west. I'm not mad about western bedrooms, especially in hot climates. But in this case it sounds like it would be used sparingly. Plus if make sure there was no western window, just a northern one. Insulating the western wall well, & using a radiant barrier (reflective insulation). The approach will also significantly shorten the length of the western hallway. Greatly increasing the size of bedroom 4. Talking room sizes, & room numbers, from a sustainability point of view, I think the home is too large for what is likely to be a two person home for much of the time. The embodied energy (emissions created) from a new build home is huge, averaging 15 years of operational energy. I'd be looking to reduce the house size, by using multipurpose rooms. The occasional kids housed in the study, or the media room. This can work out great with clever design (like incorporating murphy beds). How will the media room be used? Will noise be an issue. Will you be happy to have it so close to the master bed? The building orientation/shape will be great for solar PV, with a large roof area facing north. I'd I was building nowadays, is be aiming for an all-electric home. Ditching gas - of its even available where you are - in favour of efficient electric appliances. Reverse cycle AC for heating (if it's required), supplemented by fans for cooling, hot water heat pump (extremely efficient), induction cooktop (sensitive, fast acting, easy to clean). All powered by solar PV. If it's an option, I'd look at 3 phase power, which will let you install a larger PV system. It will also allow you install a fast charger for EV, likely to be your next car purchase, or soon after.

I would delete the wall behind the bed in the master bedroom as it doesn’t seem to serve any real purpose and turn the bed to place against the outside wall. The room will be far more spacious .