There exists a significant body of literature on energy and indoor air quality impacts of envelope leakage. In fact, this topic has been studied since the 70s and has lead to many publications, in particular within the Air Infiltration Centre established in 1979 that has become the Air Infiltration and Ventilation Center (AIVC) since 1987. Most available literature on envelope leakage characterization, measurement methods, airflow modelling can be found in the publication database developed and managed by the AIVC.
While it was a very active field of investigations in the 70s and 80s, interest for this issue has decreased in the 90s and until the mid-2000s. An important exception lies in low-energy building approaches that have encouraged pursuing efforts on research and development of methods and products. The CEPHEUS1 project (www.cepheus.de, 1998-2001) is a good illustration of work undertaken in the late 90s on very low-energy buildings that addressed specifically envelope airtightness issues. The Passivhaus standard developed since 1988 with the joint work of Professors Bo Adamson (University of Lund, Sweden) and Wolfgang Feist (Institute for Housing and the Environment, Germany) is another corner stone for envelope airtightness developments. Because extremely low leakage levels are required in these types of buildings (n50 below 0.6 ach), some professionals have progressively developed methods and products to reliably tighten building envelopes. Therefore, while these techniques were quite crude in the first passive houses built in the early 90s, the development of new seals, bonds, and barriers has allowed designers to be more confident to meet those stringent requirements. However, this market remained quasi-confidential until 2005.
Since 2005, there is a revived interest for topic with the recent steps taken by many countries to generalize very low-energy buildings. This trend has been clearly identified in the ASIEPI2 project (www.asiepi.eu, 2007-2010) together with the need for dissemination on methods and products to achieve good airtightness. Growing experience on this issue shows that generalizing airtight envelopes is a great challenge that calls into question the training of architects, engineers and craftsmen. This is one fundamental reason behind the TightVent Europe initiative (www.tightvent.eu).
The objective of this paper is to disseminate practical information on methods and techniques. It starts with key quality principles, continues with a description of the steps to follow at design stage, proposes classification of tightening products, and explains frequent field issues.