Describes fan pressurisation and balanced fan pressurisation tests conducted on a five-story apartment building to determine its air leakage characteristics. The overall air tightness of the building envelope and the airtightness values of the exterior walls of three individual stories were obtained, as well as the air tightness values of interior partitions, stairwells and floor/ceiling separations. Reports the methods used to measure the airtightness values and gives the test results.

KEYWORDS: Flats, testing, pressurisation, buildings, air infiltration, air tightness, walls, stairwells, leaking