Information on U-Value Data Sources

The BBA/TIMSA U-Value and Condensation Risk Analysis competency scheme is limited to specific sources of data, which are clearly stated in the scheme document.

The purpose of the Scheme Database is to include other sources of input data which are acceptable to the BBA but are not currently stated in the Scheme Document. This could range from Information Bulletins to commonly agreed conventions. It is the responsibility of the Certificate Holders to make sure that the Competent Person is familiar with the scheme database and uses the information in the correct manner.

Below is a list of documents that are currently part of the Scheme Database. If you require clarification on any of these, please contact the BBA by emailing

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