This paper presents the new framework for the realization of reliable pressurization tests in Belgium and the provisions taken to widen the number of buildings where a valid pressurization test can be realized. The pressurization test is described in standards. In Belgium, the measured airtightness performance can be used in the regional Energy Performance (EP) regulations in order to improve the calculated performance. A few years ago, supplementary specifications to the test standard (NBN EN 13829) describing detailed specific elements of the test, were added to the regulations. Testing is not required by the regulations but a relatively unfavourable default value for the airtightness has to be used if no test is carried out. With the progressive strengthening of the energy standards included in the regulations, the airtightness performance has become more and more important. Measuring the airtightness is a common practice nowadays. In some Regions, over 50% of the buildings is now tested. Up to 2014, in Belgium, requirements have not been imposed on the testers. Everyone in possession of the test equipment could realize a pressurization test and could use the test result in the EP regulation. Moreover, several years of experience with the regulations show specific situations where the strict respect of the test standard is not always possible (e.g. in high buildings).