@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.

As Australias largest supplier of hydronic heating, we have been providing Australian homes with stylish, safe and comfortable hydronic heating and cooling solutions. As exclusive stockists of an extensive range of premium products, we ensure that all homes can enjoy the benefits of a low carbon, energy efficient system. We have just released an industry leading guide on Underfloor Heating, that contains information for both homeowners and installers, I believe the content within would be the perfect for many commenters on this post. If you're unsure on how to proceed with your project I recommend you take full advantage of our personalised consultation service, available for both homeowners and installers. Using the latest design software and coupled with the expertise of our Customer Service Team, you can rest easy knowing that we’ll design a bespoke solution that delivers superior comfort that is also environmentally friendly and energy efficient. If you would like a copy please email me on sophieo@huntheat.com.au, alternatively head to our blog to download a copy: Hunt Heating Blog

As Australias largest supplier of hydronic heating, we have been providing Australian homes with stylish, safe and comfortable hydronic heating and cooling solutions. As exclusive stockists of an extensive range of premium products, we ensure that all homes can enjoy the benefits of a low carbon, energy efficient system. We have just released an industry leading guide on Underfloor Heating, that contains information for both homeowners and installers, I believe the content within would be the perfect for many commenters on this post. If you're unsure on how to proceed with your project I recommend you take full advantage of our personalised consultation service, available for both homeowners and installers. Using the latest design software and coupled with the expertise of our Customer Service Team, you can rest easy knowing that we’ll design a bespoke solution that delivers superior comfort that is also environmentally friendly and energy efficient. If you would like a copy please email me on sophieo@huntheat.com.au, alternatively head to our blog to download a copy: Hunt Heating Blog

Hydronic (in floor or panels) is the most comfortable and cost effective heating option. No it's not "cheap" if taken on face value alone of installation cost, but when it's looked at as a long term investment it's a fantastic option for new builds. Depends on the longterm goals you have (for living in this particular house) and where your personal priorities lie in regards to comfort/costs/sustainability etc. Typically for in floor hydronic for standard house size it's probably ballpark $15-20K give or take depending. But if you consider 4x good quality split systems will equate to similar cost, in colder climate zones it really is a good option considering the quality of invisible silent and comfortable embodied heat as opposed to fan forced stratified dry hot air from an ugly visible fitting. Best of luck PD www.pauldistefanodesign.com