This Technical Report has been prepared by Technical Committee CEN/fC 1 56, Ventilation for buildings. This Technical Report is intended to assist in providing an acceptable indoor environment for people in ventilated buildings.This Technical Report specifies the requirements for, and methods of expressing the quality of the indoor environment for the design, collllllissioning, operation and control of ventilation and airconditioning systems. This Technical Report covers indoor environments where the major concern is the hwnan occupation but excludes dwellings. Tilis Technical Report does not cover buildings where industrial processes or similar operations requiring special conditions are undertaken. The practical procedures, including selection of parameters to be measured during commissioning, control and operation, are not covered.