We are currently getting asked more and more about if our products in particular Expanding Foam has a GWP (Global Warming Potential) of less than 5.

Below is an email response from Soudal, manufacturers of Silicones, Adhesives and Foams.

We are aware of The Code for Sustainable Homes and the GWP but as usual, it is not that simple to test and come up with an answer.

The AKPU, the association of PU foam manufacturers, has commonly agreed to allocate a factor of 10 to any foam although there will be foams with lower values.

The technical guide of the code specifies a number of categories where credits can be gained. The ones relating to our products are 3 Materials and 6 Pollution.

The materials section lists on p127 that ‘insulation materials, fixings and adhesives are excluded from the assessment’.

For pollution, there is only 1 potential credit available (out of a total of 104) and there are no mandatory elements. The 1 credit is awarded where all insulating materials in the elements (roofs, walls, floors, hot water cylinder, cold water storage tanks and external doors) only use substances that have a GWP < 5 (manufacture and installation).

The above means that using foam with a GWP of 10 prevents you from getting 1 out 104 possible credits. It is further not unlawful to use these foams – it just lowers in a very minor way your chances of obtaining a Level 6 rating instead of the lower levels.


Remark: The directives contained in this documentation are the result of our experiments and of our experience and have been submitted in good faith.
Because of the diversity of the materials and substrates and the great number of possible applications which are out of our control, we cannot accept any responsability for the results obtained. In every case it is recommended to carry out preliminary experiments