Is good building airtightness compatible with good indoor air quality?

Yes, provided that the building is equipped with an appropriate ventilation system (whether natural, mechanical or hybrid). A recent French study mentioned in the AIVC newsletter n°2 shows that better building airtightness converges with better indoor air quality because the ventilation system operates more efficiently. Building leaks cause uncontrolled airflows and potentially poorly ventilated rooms although the total building air exchange rate may be sufficient [1].

[1] L. Mouradian and X. Boulanger, “QUAD-BBC, Indoor Air Quality and ventilation systems in low energy buildings,” AIVC Newsletter No2, June 2012.