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Evolusion certified by the BBA under the U-Value Competency Scheme


The British Board of Agrément (BBA) operates a scheme for assessing and monitoring U-Value and condensation risk calculation competency. The scheme seeks to promote and assist accurate, objective and consistent calculation of u-values and condensation risk within buildings.

To maintain our committment to expertise in our fields, Evolusion sought and surpassed the competency levels required to obtain this certification. Registration under the Scheme provides reassurance to any specifier or user that the services or data being provided are supplied by an individual or company that has been subject to a rigorous independent assessment process. Our clients can therefore be assured that our outputs in these areas are representative and reliable.


To qualify for certification Evolusion were subjected to

  • an initial screening

  • an office inspection

  • validation and conclusions

and we will be monitored through ongoing surveillance by the BBA.

u-value and condensation risk calculations

SAP 12



U-value entry (walls, roofs, floors)
"The U-value is that of the whole element, including any added insulation. Documentary evidence applicable to the property being assessed must be provided and recorded if overwriting any default U-value. This evidence shall be either:
- relevant building control approval, which both correctly defines the construction in question and states the calculated U-value; or

- a U-value calculation produced or verified by a suitably qualified person.
Evidence of suitable qualification is through membership of a recognised U-value calculation competency scheme (BBA/TIMSA (UK)), OCDEA membership (England & Wales, Northern Ireland) or any other scheme formally agreed between Accreditation Schemes/Approved Organisations and Government."

Evolusion clients can be assured that our U-Value and condensation risk calculations are backed by our BBA Certificates of Competency and our Check-the-Checker quality control methodologies.


ECO2 Cavity wall u-value checklist

"This checklist should be used in all cases where a wall U-value is overwritten for a cavity wall insulation (CWI) measure."

Where it is necessary to justify a U-value higher than the threshold,  one acceptable method of doing so is to have the calculation produced or verified by a suitably qualified person such as a member of a recognised U-value calculation competency scheme (i.e. BBA/TIMSA).

As our Building Physics engineers are BBA certified competent persons, Evolusion can assist you in complying with this requirement.

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