Specifics of Building Envelope Air Leakage Problems and Airtightness Measurements Anatolijs Borodinecs, Jekaterina Nazarova, Aleksandrs Zajacs, Alexandr Malyshev and Vladimir Pronin MATEC Web Conf., 73 (2016) 02020 Published online: 11 August 2016 DOI: 10.1051/matecconf/20167302020