Life Cycle Assessment of Building Renovation Measures–Trade-off between Building Materials and Energy

Abstract

The scope of this study is to assess how different energy efficient renovation strategies affect the environmental impacts of a multi-family house in a Nordic climate within district heating systems. The European Union has set ambitious targets to reduce energy use and greenhouse gas emissions by the year 2030. There is special attention on reducing the life cycle emissions in the buildings sector. However, the focus has often been on new buildings, although existing buildings represent great potential within the building stock in Europe. In this study, four different renovation scenarios were analyzed with the commercially available life cycle assessment software that follows the European Committee for Standardization (CEN) standard. This study covers all life cycle steps from the cradle to the grave for a residential building in Borlänge, Sweden, where renewable energy dominates. The four scenarios included reduced indoor temperature, improved thermal properties of building material components and heat recovery for the ventilation system. One finding is that changing installations gives an environmental impact comparable to renovations that include both ventilation and building facilities. In addition, the life cycle steps that have the greatest environmental impact in all scenarios are the operational energy use and the building and installation processes. Renovation measures had a major impact on energy use due to the cold climate and low solar irradiation in the heating season. An interesting aspect, however, is that the building materials and the construction processes gave a significant amount of environmental impact.

Development and Performance Assessment of Prefabricated Insulation Elements for Deep Energy Renovation of Apartment Buildings

“…Energy performance of building directive (EPBD) [3] requires all new buildings to be nearly Zero Energy Buildings (nZEB) as of the year 2020 and to renovate almost all buildings by the year 2050. Due to the reduction of energy use during the lifetime of buildings, renovation resulted in a reduction of global warming potential [4]. Case studies have shown the viability of the nZEB renovation measures to improve the condition of residential building stock in Croatia [5], Spain [6,7], Poland [8], and the Mediterranean climate [9].…”

Environmental Payback of Renovation Strategies in a Northern Climate—the Impact of Nuclear Power and Fossil Fuels in the Electricity Supply

“…For this building, eight renovation scenarios were assessed (already defined in [19]). Different combinations of renovation measures were assessed, such as added insulation, energy efficient windows, and heat recovery ventilation (HRV).…”

“…The proposed measures have previously been studied by Ramirez-Villegas et al [19], who consider the electricity mix in Sweden, whereas in this study the electricity mix for different countries has been considered. In Table 2 all used material data is compiled.…”

Combined Environmental and Economic Assessment of Energy Efficiency Measures in a Multi-Dwelling Building

“…The PV production was estimated using PVGIS [18]. More details of the energy simulation can be found in [17,19]. In this study, the energy demand is that stated in the Swedish building code [20] regarding space heating, domestic hot water and facility electricity.…”

“…The proposed measures to improve the building envelope have previously been studied in Ramírez-Villegas et al [19]. In this study, photovoltaic panels and a geothermal heat pump were added to the renovation scenarios as these are considered to be cost-effective measures in Sweden [21].…”