Originally Posted by Dead Metal
Excellent start "outdoorbloke" ! looks rather compact ? and welcome, best of luck .
If the 600k budget includes labour, plumbing ,electrical, fixtures and fittings... certainly doable.
Given that heat rises I can never understand why ceilings are insulated rather than the roof panels/frame or just installing suitable venting and perhaps painting the roof and house white. I remember seeing gyproc with foil on the back to reflect heat up.
In temperate climates ceiling insulation is used to keep the heat in?
Anyways good luck..