If your house is "solid construction", such as solid timber, concrete or rammed earth you will need to check the Acceptable Solution for Clause H1 for other insulation options.
There are tables of insulation requirements for solid construction that can be used instead of the R-values tabulated above.
The lower wall R-values for solid wall construction account for:
- The performance benefits of thermal mass:
- thermal mass must be used in conjunction with good passive solar design to increase comfort and to reduce energy use.
- Higher roof R-values:
- this is a trade-off to reduce the wall insulation by increasing the roof insulation.
- Higher floor R-values for some options:
- this is a trade-off to reduce the wall insulation by increasing the floor insulation.
If your house has a mix of timber-framed walls and solid walls, you cannot use the simple tables and will need to use another method to demonstrate compliance with the Building Code.
The most robust way to analyse a combination of different construction types in the same house is to use the modelling method in the Verification Method H1/VM1.
We suggest the best and easiest way to analyse mixed construction is to use the calculation method in the Acceptable Solution H1/AS1.