MAXRaft® R-value Calculator

Complete the fields below and we will match your answers to the most suitable product(s) from our Product Range to meet & exceed the requirements of H1.

This selection tool is designed to work with internal area/perimeter ratios between 1.6 & 4 as per our Thermal Modelling V4. For smaller or larger ratios please contact us.

The calculator is designed to give you more than one product option where possible.


* The next version of the calculator will factor in cladding ratios (i.e. brick), if you have brick anywhere please choose yes for the most conservative R-value.
** The calculator/thermal modelling does not allow for penetrations through the underneath of the slab other than plumbing/drainage. Contact our team to discuss specific R-value calculations if required.
*** Email to request an H1 Compliance document for council if required.

Don't know your climate zone? See map


Product(s) will be shown here after you click the "View Results" button.

How to use the R-value Calculator