Appendix D: Reporting evidence of compliance

  1. Reporting evidence of compliance

    Reporting evidence of compliance

    1. To facilitate effective communication between the builder and BCB, it would be beneficial to adopt a standardised format for presenting the evidence that demonstrates compliance with the energy efficiency requirements. (Other than the CO2 target which is mandatory, the limiting values for individual fabric elements and building services represent reasonable provision in normal circumstances. In unusual circumstances, alternative limits may represent reasonable provision, but this would have to be demonstrated in the particular case.)

    2. Since the data in compliance software and the results they calculate can provide a substantial proportion of the evidence in support of the compliance demonstration, compliance software should produce this report as a standard output option.

    3. Two versions of the standardised report may be produced by the compliance software: the first before commencement of works to include the TER/BER calculation plus supporting list of specifications, and the second after completion to include the as-built TER/BER calculation plus any changes to the list of specifications. The first design-stage report and accompanying list of specifications can then be used by the BCB to assist checking that what has been designed is actually built. A standardised report should enable the source of the evidence to be indicated, and allow the credentials of those submitting the evidence to be declared.

    4. An important part of demonstrating compliance is to make a clear connection between the product specifications and the data inputs required by the compliance software (e.g. what is the wall construction that delivers the claimed U-value?). Examples as to how compliance software might provide this link are:

    a. By giving each data input a reference code that can be mapped against a separate submission by the builder/developer that details the specification corresponding to each unique reference code in the data input.

    b. By providing a free-text entry facility along with each input parameter that has a unique reference code, thereby allowing the software to capture the specification of each item and so include the full details in an integrated output report.

    c. By including one or more utility programs that derive the data input from the specification, e.g. a U-value calculator that conforms to BR 443 and that calculates the U-value based on the layer thicknesses and conductivities, repeating thermal bridge effects etc. Outputs from such a utility program could then automatically generate the type of integrated report described at sub-paragraph b.

    It would also help the BCB if the software included a facility to compare the ‘as designed’ and ‘as constructed’ data input files and automatically produce a schedule of changes.

    5. The report should highlight any items whose specification is better than typically expected values. The BCB is advised to give particular attention to such ‘key features’, as their appropriate installation will be critical in achieving the TER.

    It is expected that low and zero carbon technologies will increasingly be employed for compliance, particularly where the average performance of elements in the actual building is worse than the concurrent specification. The report should highlight where these low and zero carbon technologies have been used and the BCB is advised to give particular attention to their installation.

    The BCB is advised to give particular attention to those aspects where the claimed specification delivers an energy efficiency standard in advance of that defined in the following schedule.