Cavity Assessment Surveillance Scheme (CASS®)

CASS® – What is it all about?

For many years the British Board of Agrément has issued Agrément Certificates for cavity wall insulation and these, together with the related BBA Approved Installer Scheme, have provided high levels of assurance in respect of the some six million cavity wall insulation installations carried out over the past 20 years.

The BBA is continually looking to learn from experience and use those lessons to improve outcomes for the industry and consumers. With regard to the retrofitting of cavity wall insulation it is clear that, in some cases, consumer confidence is being undermined by the perception that insulation is being installed into properties which are unsuitable.

To seek improvement in this area and to increase consumer confidence, the BBA has developed a Cavity Assessor Surveillance Scheme (CASS®) covering Property Assessors. CASS® will check at the beginning of the process the suitability of properties proposed by Property Assessors for cavity wall insulation, and will provide independent third-party validation of suitability.

The costs of providing this additional level of consumer reassurance will be borne by the industry, not by the consumer, with the BBA ensuring a seamless process. Having liaised with the industry, DECC and the Guarantee Providers, we know that the major stakeholders are fully supportive of CASS® and we are confident that, in many cases, a successful CASS® check will become a requirement for the issuing of guarantees.

What does it mean for CWI property Assessors?

Cavity wall property assessors working for companies that are using other BBA approved products or utilising a CIGA guarantee will be required to have all property assessments verified by the BBA property assessment staff. This new scheme is scheduled for introduction in April 2017.

What does it mean for householders?

The Cavity Assessment Surveillance Scheme is being introduced by the BBA in an attempt to ensure that the property assessor who carries out a property service on a home does so against a strict set of requirements. Experienced BBA staff will determine if the property assessment satisfies the requirements which need to be in place for the successful installation of cavity wall insulation. Only BBA approved property assessments will qualify for CIGA guarantees.

For further information on CASS® and related matters, please telephone 01923 665322 or email

Lodging assessments on the CASS® platform

The videos below show how to lodge your cavity assessments onto the CASS® platform.

For assessors:

For company administrators: