I can only give you my experience. I've lived for over 20yrs on real hardwood floors. And every time I stand on any kind of laminated plank it looks and feels like cheap plastic. There is just no comparison to actual wood flooring. Timber absorbs vibration, feels pleasant underfoot either barefoot or shoed. It looks real, because it is. Timber planks are 20mm thick, laminate ones are 5mm. Laminate flooring looks like a printed piece of plastic because, well it's very similar except for the top 2mm of veneer stuck to it. It may fool us in brochures and magazines but I've never once been fooled by laminate in person. They can give it all the fancy names they want like 'engineered' but at the end of the day it's all the same stuff. Laminated veneers on cheap plywood. But not one person on the planet has ever fooled that it's a real floorboard. Does timber scratch? Absolutely. So don't put a piano finish on it then. Stick with satin and matte finishes. It shows up the marks a lot less. Does timber dent? Absolutely. But those dents become part of the character of the home over time. I recently lived in a home with floorboards over 100yrs old. They had dents everywhere and yet those boards just looked lived on, they didn't look terrible. Does timber suffer water damage? Yes of course. But before you worry about it, go and check out the thousands of 100yrs old hardwood homes sitting on flood plains in this country. Every single one of them has been underwater more than once in it's lifetime. The original boards are there, strong and unfazed. Unless you plan to flood your home for weeks on end the occassional spill and overflow won't damage the timber at all. I'm a quality over quantity type of person so of course I'm going to rate going with the lifetime option over the rip it out every 5yrs option. If I had the money for hardwood I would not even consider plastic planks.

I have came across waterproof laminate floor with 15 years waterproof warrenty. Please see Quick Step Laminate Impresive Ultra floor boards. They look quite impresive. I am trying to decide between waterproof laminate and hybrid floor. Please see my post here https://www.houzz.com.au/discussions/6004056/laminate-vs-hybrid-waterproof-floor-board#n=0 Can you please give your input?

Love it as is. Well done. The void above living will let on light, just be careful of not letting in the western light too much. So some way to shade house on the backyard end. would be good.

electric underfloor heating is great for bathrooms (and laundry, mudrooms, entry and hallways when it needs to be left on for weeks at a time and not much good for a ten minute shower) and is preferable to anything visible like hydronic heaters that take up wall space but your voids will suck most of the heat upstairs ..our reverse cycle AC has been much more economical to run than the whole floor electric slab heating that we had in our previous house (supplemented with a wood burner and gas log fire in our cold climate) but we made sure that the void over the stairs was able to be blocked off to zone heat downstairs with separate heating upstairs but having lived in different areas of Sydney i'm wondering why a new built well designed house with great insulation would need more than modest supplementary heating that can be more economically provided with AC