We collected information on existing envelope air leakage databases from countries that are involved in the AIVC-TightVent project “Development and applications of building air leakage databases”. This document summarizes the information from five countries: Czech Republic, France, Germany, UK and USA. Even though our summary is not exhaustive of all existing data on whole-building envelope air leakage, it provides an overview of recent efforts from a number of countries. There are many reasons why different countries are collecting these data. We will summarize their motivation, which drives some of the differences in the types of data being gathered and how the data are analysed. Detailed information from each country is provided at the end of this document in the form of tables.