Thanks guys, the house has no heating or cooling just now. So fresh start. I will have to see how the building responds once I get out, etc. I am a a real automation geek, so will employ all the automatic closing of shades, auto dimming glass, etc, to reduce solar gain as much as possible. But very keen to make a comfortable environment as 35 - 45 C is normal in the summer. I will have a PV system also of course to run the ASHP.