INDOOR ENVIRONMENTAL CRITERIA FOR DESIGN AND CALCULATION OF ENERGY PERFORMANCE OF BUILDINGS – EN15251

European Directive for Energy Performance of Buildings (EPBD) was approved in the beginning of2003. The transition period is 3-6 years depending of the article. European StandardisationOrganisation (CEN) has drafted several standards to help the member countries implementing thedirective. One of these is the Criteria for the indoor environment including thermal, indoor air quality(ventilation) light and noise. The standard specifies design values of indoor environment, values to beused in energy calculations, and methods how to verify the specified indoor environment in thebuildings. The standard includes methods for long term evaluation of the indoor environment. Thepaper describes some of the principles used in standards, and gives examples presented in thestandard. A draft standard has been under the international review process and is now being issuedfor final approval.