The TightVent Airtightness Association Committee (TAAC) held four meetings over the past year, all organised as virtual sessions, as only a few TAAC participants attended the AIVC–ASHRAE IEQ joint conference in Montreal this year.

As in previous years, the September TAAC meeting hosted this year its traditional “News from Countries” session, featuring updates and developments from across the network, in particular in:

• Denmark: A first presentation on the national airtightness situation was delivered by new participant Kurt Lynge Christensen, highlighting that Denmark has required a minimum airtightness level since 2006 and made airtightness testing mandatory in 2015.
• Czech Republic: Jiri Novak presented the newly published ČSN 73 0540-2:2025 standard (September 2025), which introduces required minimum and recommended airtightness levels for new buildings, differentiated according to the type of ventilation system.
• Switzerland: Michael Wehrli shared insights from the ongoing revision of SIA 180:2014, which proposes more ambitious minimum airtightness levels for both new and renovated buildings.
• Greece: Theodoros Sotirios reported on the conclusion of the public consultation for the revised national energy code, where he used data on airtightness requirements in other European countries (collected through the TAAC network) to advocate for the inclusion of airtightness requirements. He also continues to raise awareness about airtightness through social media with notable success.

In total, 11 presentations were given during this session, giving additional interesting news from Japan (Yuichi Takemasa), Belgium (Liesje Van Gelder), Canada & USA (Darren Kennedy), Netherlands (Niek-Jan Bink), UK (Luke Smith and Paul Carling), Germany (Oliver Solcher), and France (Valérie Leprince).

TAAC is pleased to welcome an increasing number of participants from new countries, further enriching the network.

The next TAAC meeting is scheduled for December 12^th, from 2:00 PM to 4:00 PM (CET). It will feature the “News from TightVent Partners” session, which was postponed from the previous meeting due to time constraints.