guard-zone measurements

Purpose of the work

With the German Energy Savings Regulation EnEV 2014 the legislators have qualified the requirements for large apartment buildings (V_L > 1.500 m³). In addition to the air change rate (n₅₀ ≤ 3,0 h^-1 or n₅₀ ≤ 1,5 h^-1 depending on the ventilation technology used) the envelope-based air permeability (q₅₀ ≤ 2,5 m³h^-1m^-2) is now also required.