Reasons behind and lessons learnt with the development of airtightness testers schemes in 11 European countries
Mandatory building airtightness testing has come gradually into force in the UK, France, Ireland and Denmark. It is considered in many other European countries because of the increasing weight of the building leakage energy impact on the overall energy performance of low-energy buildings. Therefore, because of related legal and financial issues, the building airtightness testing protocol and reporting have become crucial issues to have confidence in the test results as well as the consistency between the measurement results and values used in the energy performance calculation method. The reference testing protocol in Europe is described in EN 13829. In addition, many countries have developed specific guidelines to detail or adapt EN 13829 requirements. However, performing and reporting correctly an airtightness test requires knowledge and know-how as well as pre-requisite on the tools used by the tester.
This study compares the steps taken in 11 European countries to improve the competence of the testers and thereby the reliability of the airtightness measurement. Information has been collected through a questionnaire sent to TAAC (TightVent Airtightness Associations Committee) members. The study finds that 8 out of the 11 countries surveyed have developed or were developing a competent tester scheme for airtightness testers. Those schemes go together with technical documents beyond the measurement standard and include most of the time training, examination of testers and the proof of use of appropriate equipment. The feedback from France from the training institutes and experts analysing the reports of applicants as well as the failure rate at the examinations confirm that performing and reporting correctly an airtightness test is not straightforward. Those schemes are reinforced with databases that allow better follow-up of the approved testers and tracking of suspicious results.