How to construction an airtight building? How to avoid the most common leaks?

Buildings are a composition of various materials and components, and have multiple edges, overlaps, joints, ... These are not always carefully closed. To ensure good airtightness everywhere, a continuous airtight layer needs to be defined and implemented. Typical weak spots are: connections between outside & inside walls, roofs & floors; outside woodwork, rolling shutters, and their connections with outside masonry; the various connections for the sewage and ventilation system; electricity, sanitary and heating tubes; openings to insulated attics or doors to unheated cellars, ... It’s only possible to realize an airtight construction by careful detailing  together with special products and a high quality  craftsmanship.

Source: Passiefhuis - Platform