As of 1 September, the British Fenestration Rating Council (BFRC) requires that all spacer bars needing a measured thermal conductivity value be obtained from a current Bundesverband-Flachglas (BF) datasheet. This new criteria will affect BFRC ratings in the following way:
New licences
Thermal conductivity values used within BFRC rating calculations will need to be clearly identified as either a generic tabulated value (taken from BS EN ISO 10077-2: 2012 or BS EN ISO 10456: 2007), or a measured thermal conductivity value taken from a current BF 2-box model datasheet. New applications requiring a measured value that do not contain a two box model datasheet value will not be accepted. To clarify, all new licence applications must be fully compliant with BS EN ISO 10077-2:2012.
Existing licences
Data contained within an existing simulation report which has been used to determine the performance of a currently licensed product, will remain valid provided the component parts simulated are currently commercial available. The existing licence will remain valid for five years from the date of issue. In cases where component parts are no longer commercially available and BFRC substitution rules are not applicable, re-simulation will be required.
Substitution
There has been no change to the criteria for the substitution of component parts. Where spacer bars (including the primary sealant and desiccant) are to be substituted the replacement will need to be an equal or lower effective thermal conductivity (measured to three decimal places) than the spacer bar specified in the original licence.
Further details will be made available shortly.
