Promotion of sustainable renovation in the built environment : An early stage techno-economic approach

Sammanfattning: According to the Swedish Government's set targets for energy use and environmental quality imposed by the European Union, the total energy per heated unit area in residential and commercial buildings will have to be decreased by 20% in 2020 and 50% by 2050 in relation to the annual consumption of 1995. The building sector should additionally be completely independent of fossil fuels for energy usage, with the increasing sector of renewable energy continuously growing until 2020. In its current state, the number of multistory buildings and single-family houses in Sweden exceeds 4 000 000 units. In order to attain the set goals, renovation of the existing housing stock is a necessity given its current relatively slow turnover. As a result of the Swedish Million Unit Program undertaken during 1965−1974, about 750 000 apartments are currently in need of renovation in order to meet today's building standards. Simultaneously, new buildings are built with energy efficiency in mind. In this study an early stage methodology is developed for building refurbishment that takes advantage of a multi-faceted approach. The methodology comprises of multiple dimensions related to a techno-economic, environmental and building occupancy approach. The work presented herein includes a thorough literature review of decision making tools within the built environment and identifies major research efforts in sustainable refurbishment. The technical aspect of this study deals with the proper identification of high-efficient insulation materials that would serve one of the set purposes of energy efficiency when utilized within building envelopes. Further, results are shown for case studies, in which economic investments in Vacuum Insulation Panels (VIPs) and a coupled heat and moisture transport for predefined configurations of VIPs with supplementary insulation of balcony slabs and wall cross-sections are considered. The developed methodology also examines simulations of the total energy consumption utilizing a set of different insulation materials such as mineral wool and VIPs, for a number of locations in Northern and Southern Europe. The research findings of this study identify several aspects of a new developed tool for decision making, to be used in sustainable renovation and refurbishment.