There is a consensus within Europe that the built environment has a major task to reduce the CO2 emissions and convert to sustainable energy systems. The energy saving targets are high and there is a need to show in a non controversial way the achievement of the various Member States. This is one of the reasons that harmonised calculation procedures, including harmonised input parameters, are desirable. However there are still a lot of national differences in the various regulations directly influencing the EP requirement level; for example the requirements on ventilation or other health related issues. The EN 15251 “Indoor Environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality thermal environment, lighting and acoustics “ has been developed to give the MS regulators the opportunity to harmonise these requirements.
See also question "What are the future prospects for the status of the CEN standards?" and other related questions.
Question submitted by: Dick van Dijk (TNO, The Netherlands)
Anwered by: Dick van Dijk, TNO and Jaap Hogeling, ISSO (The Netherlands)