Hello Taryn If it was my home I would get ducted reverse cycle air conditioning because of our summer weather patterns. Our winters in Perth are quiet mild compared with the east coast of Australia. Reverse cycle air conditioning handles both heating and cooling. Contact Gmtair they offer all different levels of service for ducted air conditioning in Perth

For a Perth climate I would choose reverse cycle Aircon which takes care of any extreme weather easily, hot and dry, humid, cold. Under floor heating is lovely in bathrooms and would only be needed for a few months of the year

Taryn - I'm assuming you mean underfloor electric heating, not hydronic heating? The former is very expensive to run as your only heating - better for bathrooms that you need to heat only for a short time each day. A split system heat pump A/C unit would be the way to go - very efficient and you get cooling as well as heating. But, with good passive solar design you may not need any heating or cooling - maybe wait until you have lived in the house for a year? having said that - you could get the split system piping roughed into your walls while you are building to give you the option later, without ugly conduit running across walls.

Thanks for your input everyone.
Yes we are hoping that we have designed the house well enough that ceiling fans will suffice in summer. However given the concrete flooring, I think we will definitely need a form of heating. I have just received a quote for hydronic underfloor heating and although alot cheaper to run than electric, the installation cost is outrageous!
I like the idea of preparing the house to install a/c at a later date if required. Perhaps that might be the best solution. Thanks!

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

Thanks Paul, I agree with all of the above. However for a similar cost (actually more) than ducted a/c you only get half the functionality. Living in Perth as we do, we'd be leaving ourselves open to potentially having to install a/c as well

Yep and so depends on what you'll use more. But heating from ceiling diffusers is not the best option for heating as hot air rises. Perfect for cooling though. Ideally you have both, but of course it's not cheap. The majority of our work is in Victoria so it's typically about heating being the priority over cooling. You however probably have the inverse scenario over there so it depends on how much you'll be using one over the other. Probably in your case ducted a/c will arguably beused more months out of the year as opposed to heating....