Rationale and pros and cons of various approaches for setting building airtightness requirements

This paper analyses approaches for setting airtightness requirements whether in voluntary or regulatory schemes. We have classified approaches for upper limits into two major types: default values and minimum requirement. Lessons learnt from existing schemes where minimum requirements have been enforced show that the scheme to justify a given airtightness level is one fundamental ingredient in terms of market impact. In France and in the UK where justifications are based on testing and additional quality measures if performed on samples, a market transformation is clearly underway and building professionals gradually revisit their methods to meet airtightness requirements. This trend does not appear to be nearly as strong in countries that have not given a clear signal to justify airtightness levels claimed.