Façade walls are the largest area of the building envelope. That's why it is advisable to be as simple as possible and with a smaller area as possible. The façade walls can be made of various materials and systems, but this does not relieve them of the most important obligations: heat insulation, waterproofing, airtightness and permeability.
Energy losses through facade walls can reach up to 35% of total heat losses of buildings. Therefore, no matter how simple setting of facade walls looks, it requires a lot of knowledge, attention and precise details. Otherwise, all those already well-known problems are following: mold, moisture, draft, high bills for heating and cooling and deteriorated health.
According to the recommendations for energy efficient buildings, the thermal conductivity of the facade walls should be Uwall≤ 0.35 w/(m2K), while for the Passive House standard Uwall≤ 0.15 w/(m2K).