On the energy efficiency of the building envelope’s thermal performance: Perspectives and challenges

On the energy efficiency of the building envelope’s thermal performance: Perspectives and challenges

By: Agis M. Papadopoulos

It has been a long way from the first energy regulations in the 1960w to the Zero Energy Buildings required by contemporary regulations. The way has been paved by intensified, systematic developments, of an advanced, and experimentally well validated, interdisciplinary theoretical background, by its incorporation in the syllabi of most engineering and architectural university courses and by a legislative framework that transcended national regulations and standards offering European directives and harmonized European standards. There is a direct relationship between those developments and the progress made in the field of building materials and systems. The successive, ever tightening regulations act as driving forces for the development of effective insulating materials, airtight buildings and smart façades, not to mention the HVAC and  predictive BAC systems. It is the availability of those building elements and materials that enables the implementation of ambitious and innovative designs, ensuring that fewer limitations are imposed on the architects’ work. Still, thermal loads still account for almost two third of the buildings’ loads. The further reduction of those loads becomes a more challenging task, the lower the loads become in absolute terms; it is this challenge that calls for new, more advanced building materials and elements but also for a more sophisticated, integrated regulatory approach.