Buildings are responsible for 40% of Europe’s total primary energy consumption. Residential buildings represent about 80% of the total building stock. There is much need to transform older residential buildings and current retrofitting practices leave considerable room for improvement. Now, a EU funded project, MeeFS, due to be completed in 2015 is developing an innovative multifunctional façade system for residential buildings. The aim is to significantly contribute to their energy efficiency. Project coordinator Magdalena Karolina Rozanska, expert in eco-efficiency in the R&D division of Acciona Infrastructures in Madrid, Spain, talks to youris.com about the merits of retro-fitting older buildings to improve their energy efficiency. How did you get involved in retro-fitting? In 2010, the transformation of buildings, especially the multi-familiar buildings and districts constructed in mass, was identified as important to increment energy efficiency. I am familiar with the Polish situation, her native country, where many new districts grew, after World War II. The aim was to settle as many families as possible in the shortest time possible. They were based on prefabricated systems, not integrating innovative technologies, at that time not very accessible. The situation in Spain seemed similar, with differences in building typology. Thanks to experiences gained during earlier research and by multidisciplinary team-work, Acciona drew the outlines for the project idea. What is unique about your approach, compared to existing systems? Most existing retrofitting solutions only offered thermal insulation and had few aesthetic qualities. They were also rather uniform in their applicability to different types of buildings and different façade orientations. We aim to bring a solution that is easy and flexible to adapt for different architectonic configurations and typologies. And one that is modular. So it can combine different technological solutions available on the market as well as innovative breakthroughs. Modularity offers the possibility to personalise building façades to be retrofitted, depending on the wanted aesthetics and the local energy needs. And façades based on the same structural system, composed with easy to transport and assemble industrial elements. The lower intrusiveness makes the retrofitting operations more comfortable, as normally people do not move from their flats during the works. What is big picture view associated with retro-fitting? The standardised panels and technological modules will include a technology to reduce energy demand or to supply renewable energy. They will be made from low weight composite materials, based on a new industrialised constructive system with non-intrusive installation. This will allow individual configurations for any façade type, orientation and local climate conditions. They will need low maintenance and will be easy to assemble and disassemble. Is this technology focussed towards any particular building type? Collective dwellings represent 47% of the residential building stock in the first 25 EU member States. A majority of them were constructed without considering energy efficiency. The project focuses on these buildings. But recently developed systems need time to reach conformity with all EU and national laws as well as to get standardised. Also laws and standards themselves need time to get actualised following the progression of technology. An innovative system cannot be implemented as long as it or integrated elements are not standardised. Another problem is the seven-year payback time we aim for. Innovative technologies are expensive and not very accessible on the market. If an efficient innovative element is too expensive, the whole system becomes too expensive. It is possible that without this element, the system is not the best choice for some specific, complex building types in a specific climate situation. What are the achievements to date? We dimensioned a standard façade system module and defined its detail design. We selected technical units for the demonstration building and their distribution on the façade. We established the most suitable unit configuration to ensure the best possible energy performance balance of heating and cooling loads for different climate locations. The design for two energy efficient modules is also complete. What remains to be done? We have now gone far in finding a suitable composite material and its manufacturing process to match the mechanical and fire resistance requirements. This year, the project consortium will start to demonstrate and evaluate the research development on a selected demo building in Merida, Spain. This building will be monitored before and after the retrofitting with the new system. The final results will be presented at the end of 2015.