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.

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