Sakis Triantafyllakis interviews Dr. Elena Dascalaki, senior researcher at the Institute for Environmental Research and Sustainable Development of the National Observatory of Athens on the energy performance and environmental footprint of buildings. Dr. Dascalaki talks about her work at the Energy Conservation Group of the Institute where they study the behavior and energy performance of buildings, the challenges and the importance not only of developing new zero energy structures but also upgrading existing older buildings to have close to zero energy performance, a feat that is substantial especially considering the large amount of old structures all around Europe. Dr. Dascalaki tells us they were instrumental in helping develop the regulations for energy performance of buildings and says they are working on new strategies to upgrade and refurbish old buildings in Greece and Europe to meet the EU mandate that all residential buildings will have to be built or upgraded to be zero or near zero energy, relying solely on renewable sources by 2020. This project she says will be first implemented for all public buildings which will have to make the switch by 2019. Interviewed by Sakis Triantafyllakis for Tech Talks Central.