This document gives guidance on the process and development of extended fields of application using test results obtained from CEN/TS 1187, tests 1 to 4, and included in test reports, and other relevant information in order to evaluate and classify the performance of roofs/roof coverings. This document provides a methodology to consider the possible effect(s) on classification to EN 13501-5 from single or multiple changes to the individual product and end-use application parameters of the roof/roof covering. Specific application guidance is given in Annex A, Annex B, Annex C and Annex D for CEN/TS 1187, tests 1 to 4 respectively.