As previously mentioned, not traditional baths can be a nightmare with kids, so if kids are on your agenda, have a good think. Also, if you are not going to stay in the house for a LONG time, consider resale. Parents look for traditional baths for young children and non-traditional bathrooms look good, but can be a real turnoff. If this is your forever, no-kid home, go for it. If not, perhaps reconsider. I am also wondering why you are looking to spend so much on a bathroom that you will not be using (apart from the bath)? Just be careful you haven't overspent/overcapitalised on a portion of the house that really only needs to be functional and modern. People might love the bathrooms on the block, or whatever, but they buy houses in their price-range with functional amenities. Just some food for thought. Good luck with the build.

If you search DIY banquette on Pintrest you’ll see instructions and measurements. Most are in inches but you can convert them. Could you measure the seat height of the chairs you are using with the table (you need the table first) subtract the cushion height and that will give you the bench height. It does depend on the height and weight of those that will be using it the most, to get the best fit.

You could consider custom joinery that actually looks freestanding - purposefully creating a gap from the edge of the fireplace surround to the wardrobe & on the wall side also. This would also mean that it really does not matter if the front of the cupboards do not align with the front of the fireplace. Adding a nicely detailed leg, and a feature handle (you can get some really unique Australian made ones these days) to give some visual interest to the otherwise minimal finishes. Keep it simple & classic so it ages with your child's taste and preferences. As an example, The Design Files recent article has an image of a cupboard in a lounge area, that could be adapted to two double door units on either side of the fireplace https://thedesignfiles.net/2019/10/interiors-house-p-cjh-studio/. Seems perfect for a child of any age, or even if you want to convert the room to a more 'grown up purpose' once they leave home ;-)

Sasha, so you have an image of the building envelope you can use? How big is it? As it's a rural block, so you have a bit of leeway trying to orientate your home correctly? I'm assuming that by 'west facing', you mean the living areas must face west? That is the long sides of the home will have west & east? If this is the case I'd recommend the bedrooms face east (& south). As you really don't want western facing bedrooms, as they can get extremely hot on summer evenings, just before you go to bed. In this case it's better to have the living areas to the west (better than bedrooms anyway), & north if possible. As northern living areas will be lighter, & warmer in winter. I would definitely consider a western verandah to shade western living areas. Possibly with western deciduous climbers to offer shade in summer, allowing light in winter. Planting larger trees to shade the home from the west of possible. If, by 'west facing', if you mean a western frontage, this can be ideal for passive solar design. With the long sides of the home facing north (living areas) & south (bedrooms). But this is a more urban setup for a western frontage. I guess in a rural setting the home usually faces the frontage, ie. you already a wide home, not a narrow home. If this is the reason the home will face west - ie. not because of a limited building envelope, but so it faces the driveway - I would certainly reconsider this approach, orientating the home (& living areas to the north). oklouise has tried to link an extremely useful website, but for the link wrong I think. It's the Your Home website. A government website about building sustainable energy efficient homes, https://www.yourhome.gov.au/ I'd recommend reading it all. But start with passive design & orientation, to get your head around orientating your home correctly if it's possible. Then read up on design for climate, to see what's appropriate in your climate (if you're inland you probably want to have higher levels of internal thermal mass). Then continue to read the rest. There's extremely useful information in there.