Hi there
We are building in Perth and hoping to create a relatively thermally stable home. The block is small (200m) and is split level with the garage raised at the back and a big limestone retaining wall dividing that garage space. We will also have a parapet wall (neighbour's house) on the north boundary. So the house will be insulated by the neighbouring house on the northern wall (with a light well/vertical garden to allow light into downstairs bedrooms and upstairs living), and insulated downstairs by the limestone wall. The house faces west and has ocean views so there is lots of glass on the west. We are installing 6mm smart glass in lieu of normal glass. There is no aircon, with bedrooms and sitting areas having ceiling fans, and a pot belly for heating.
My biggest concern is the house being cold, rather than hot, but either way, I want to ensure the house is as well insulated as possible.
The house has a huge raked ceiling in the main living area which is upstairs and as far as I can see, the best insulation we can manage in a standard way is 100mm and about R3.5.
We were hoping for R4 as a minimum (wanted R5) in the ceiling. So... do we need to increase the size of the ceiling beams so that we can fit more insulation in?
There will be R5 insulation in the main bed & ensuite which is adjacent to the living area, but really, the heat is going to travel up to the top of the rake anyway, so my feeling is that we MUST insulate that raked ceiling well.
Would love any suggestions for improving thermal stability. I know the glass will be an issue...just don't think we can afford double glazing. Will make sure window treatments are air traps and that should help.
Thanks