AIVC's Ventilation Information Paper #45.2: Trends in building and ductwork airtightness in Spain summarizes current knowledge on trends in building and ductwork airtightness in Spain.
This is the second paper of a series being developed and dealing with trends in building and ductwork airtightness in various countries.
The paper can be downloaded here.
The first paper "VIP 45.1: Trends in building and ductwork airtightness in Estonia" was released in July, 2022 and can be found here.