I'm not here to argue, but an approved plan can be resubmitted as a variation for approval. The blind acceptance of an approval limits your creativity, and the clients ability to obtain the best possible solution. This problem requires thinking outside the box which is what we have offered. The client must decide if the process and cost of approval of a variation is worthwhile. They shouldn't live there wondering if only we had done this or done that due to a blind acceptance that once approved there can be no variations. Realistically everything that has been suggested should result in the need to seek an approval especially when changes to plumbing are considered. Erase what you are not happy with and redesign that space without the shackles of poor space planning. You don't have to like my suggestion but don't limit yourself either.

answering your questions: change the sliding door to a bench height sliding window and use the salvaged sliding door in the western end of the dining room where the best entry position is for the deck, you MUST have a proper legal drains do not consider anything else...the drain pipe for the garage laundry can be on top of the concrete floor, behind the washing machine and through the sink cabinet and/or under built in storage and only needs a few cms not a whole floor and no stepped up area that you would see or trip over.. the laundry can't be in a separate room as there's not enough space for a separate laundry without compromising the size of the garage...a laundry cupboard 80 cm deep is enough for the washing machine (allowing for the drainage pipe) you could use the old line cupboard to store anything you want but it's not cost effective to change, the entry foyer is already as big as in many modern homes and there's generous flatpac biw space in the small study.... the family bathroom is 2380 x 2370 (ie the old study minus 1m for hall way and wall thickness and, arranged exactly as shown to allow for the wide window there should be space for a bath up to 1800 x 750, vanity about 1200 x 500 and shower space 1200 x 800 and leftover space makes the small linen cupboard with the door deliberately opening towards the shower to use the back of the door for hanging racks for towels and clothes....btw i understood your priority was maximizing separate sleeping rooms and minimising costs...my last plan has five separate sleeping rooms plus the lounge with sofa bed totalling sleeping places for at least 10 people plus the potential for bunks in the garage so you need to decide what is most important and where you're prepared to compromise

@wuff, Thank you so much, and congratulation for your renovation, I wish you will enjoy it for so many years to come. Yes, I agree living into a granny flat next to my son was my husband wish before he passed away. It is good to be close to family. Also I love the suburb which I have been lived in for 22 years. My Daughter and her family is living close by too. Most of my close friends are living around and we always gather for a brunch, or lunch or watch movies. The good thing is most of my friends pick me up and don't let me drive most of the time when we go out. Thank you again

An undermount stainless steel sink will match well with your brushed gold tap and white benchtop. Although different in colour, the sink and tap shared same kind of texture so It won't be distracting. Colour wise, the sink will match perfectly with your white benchtop. We got some photos of our customers who have used the same kind of design before, check out the link below if you would like to have a look. https://fontaineind.com.au/colette-kitchen-laundry-tap-mixer-brushed-gold https://fontaineind.com.au/ariella-kitchenlaundry-mixer-tap-brushed-gold