@wayne For hydronics talk to Gary Flood at the Enter Shop. They are in Melbourne but he has installers everywhere. http://www.enter-shop.com.au/ Alternatively Alex at AJs Plumbing http://www.ajsplumbing.com.au/ We generally do in-slab hydronics but have also done it inside a rammed earth wall (at our office so feel free to come and look) and underneath a timber floor (several times including in our office). Insulation is critical. In a slab make sure you insulate the slab edge as well as the underside. When we talk of hydronics we generally use heat pumps to create the hot water (it's free to run if powered by PV). You mentioned wetback stoves (wood powered heating). In my view timber is only a viable option in rural settings. In (sub)urban settings the particulate pollution is a serious health issue and there is a fair chance that at some stage woodstoves will not be permitted by urban Councils. You finished by talking of ducted air conditioning. Regardless of the technology used to generate the heat/coolth, ducted systems are inherently inefficient and, in my view, should be avoided at all costs. The heat pumps can be great but the principle of pushing heated air around requires pump energy (you have to move large volumes of air). Almost all residential installations have flexiduct (not rigid as in commercial offices), the ductwork (aside from a study showing 80% of them did not meet the Australian Standard insulation code) due to its flexi-nature has lots and lots of curves and bends all of which increase the need for pump energy. This is why is it not possible to get a rated systems as you can with a split system; it is totally dependant on installation quality. You also need to be mindful of condensation issues in ductwork as heated air passes through relatively cold roof spaces, again quality of ductwork can be a big factor here.

Direct downlights over your vanity basin will cast dark shadows down your face and make you look ten years older. You are better off with softer lights either side of the mirror at eye height. If you don't believe me then grab a hand mirror and look at your face when standing under a spotlight. Save your money and buy the cheaper 3 in one heat lamp. Don't bother with the downlights over the basin - even though your electrician will tell you that is how he always installs them. Spend what you have saved on good wall lights, then you can thank me for making you look ten years younger due to better lighting and better make-up. Best of luck Dr Retro of Dr Retro House Calls

depending on the size of the room and accurate location of existing doors and windows everything is out of proportion and all the concepts are hard to understand because we don't know the correct sizes ... the baths only look about 1200mm long, or the showers are oversized compared to the other fittings and look too small for a standard towel and what is the size of the storage and what can be stored in it....you need to collect a examples of proper sized fixtures eg a bath could be from about 1500 to 1800 long and 750 wide plus enough space to clean around a freestanding bath, most toilets need about 800 x 800 space to allow for elbow and knee room but there's lots of different sized toilets for different situations, showers need to be about 900 deep and say 900 to 1800 long but depends on available space and do you want a walk in shower with or without a glass screen or a shower cubicle or wet room or Japanese style ...dimensions are easily found on any manufaturers websites but allways start with accurate dimensions of the existing space and try again

Depends on your budget. I assume you don't already have a central heating system installed in the rest of the house you can connect into? One option is electric underfloor heating. Tricky to retrofit as you'll need to tile over the top. Probably the easiest thing is a wall mounted fan heater such as: https://www.thermogroup.com.au/product/tf1000-1000-1800watt-fan-heater/ The other option is a ceiling-mounted heat lamp type unit. Not sure about turning itself off though, however any electrician might be able to wire a unit with a standard run-on timer for you.