Every house, also traditional, it should be tight. The tightness of the house protects its structure against the destructive effects of moisture condensed inside the external walls, from the air flowing outside the house. Airtightness in most European countries, also crucial for a passive house, is determined by building standards.
In typical homes, leaks are too small, that the occurring infiltration provides a sufficient supply of fresh air, and in turn large enough, that they allow the penetration of moisture from the indoor air, causing damage to the building structure.
It must be noted, that good thermal insulation of the house does not mean its tightness. In turn, of course, airtight construction does not guarantee good insulation of the house. Sealing layers are not a barrier to moisture diffusion.
Problems related to the proper sealing of window or door connections with the wall are known from everyday construction practice. This is because the degradation of the structure usually begins with them. The damage to the sealing joint is most often caused by different thermal expansion of adjacent materials. Water is drawn into the delaminated joint, it freezes in winter and bursts them from the inside.