A systematic approach for major renovation of residential buildings

Abstract

In Sweden, buildings are responsible for about 40 % of total energy use and about 10 % of total CO 2 emissions. Today more than 60 % of existing Swedish residential buildings are over 40 years old and are in need of major renovation. In addition, 15 % of all multi-family buildings and 27 % of all single-family houses were built before 1945. The increased energy use and threat from CO 2 emissions of the building sector create a need for energy efficiency. The important role that renovation of residential buildings will play in reducing the total energy used by the Swedish building sector as well as in reducing primary energy use and CO 2 emissions on both the national and global levels has been the impetus for the studies included in this thesis.The aim of the current research is to develop a methodology from a system perspective which can be used to analyze the energy use, optimal life cycle cost (LCC), energy efficiency measure (EEM) package, indoor environment, CO 2 emissions, and primary energy use of a building or a community during major renovation. The developed methodology accomplished at three different levels, i.e. building level, cluster level and district level. The methodology considers both energy efficiency and economic viability during building renovation and will also play an important role in overall urban planning. The studied buildings include both nonlisted and listed residential buildings and the tools used include building energy simulation (BES), survey, technical measurements, LCC optimization and building categorization.The results show that the combination of BES, technical measurements and surveys provides a holistic approach for evaluation of energy use and indoor environment of the studied residential buildings. The results from the current study also show that the 2020 energy target, i.e., reduction of energy use by 20 %, for the building sector can be achieved by all the studied building types and that the total LCC of these buildings are below the cost-optimal point. In comparison, the 2050 energy target, i.e., reduction of energy use by 50 %, for the building sector may be achieved by the non-listed buildings, but when the constraints relevant to listed buildings are added the cost-optimality changes as some EEMs in direct conflict with the building's heritage value may not be implemented.The investigation of primary energy use and CO 2 emissions by the residential buildings show that the higher the energy saving, the lower the primary energy use becomes, and vice versa. With the same energy saving, the heating system with higher primary energy factor results in higher primary energy use. From a CO 2 emissions point of view, EEM packages proposed to help buildings connected to a CHP based district heating system, to reduce the energy use or LCC are not consistently effective. Since these EEM packages will reduce district heating demand, the electricity produced in the CHP plant will also decrease. When the biomass is considered a limited resource, measures such as investm...

Investigating cost-optimal energy renovation of a multifamily building in Sweden

“…OPERA-MILP was developed at Linköping University, Sweden, in the 1990s to serve as a tool for identifying suitable energy renovation strategies for multifamily buildings [25]. Since then, the tool has been used in several studies of multifamily buildings [26][27][28][29] as well as historic buildings [6,30,31].…”

Optimal Planning of Hotel Renovation Projects

“…Available related research studies focused on: (1) investigating the impact of renovation on hotels performance [2][3][4][5][6][7][8][9][10][11][12], (2) improving the planning of renovation work in existing buildings [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], and (3) optimizing the planning of repetitive construction projects [30][31][32][33][34][35][36][37][38][39].…”

Energy renovation of multi-family buildings in Sweden : An evaluation of life cycle costs, indoor environment and primary energy use, and a comparison with constructing a new building

“…Several publications include studies of building renovation LCC optimizations based on OPERA-MILP (Gustafsson, 1998(Gustafsson, , 2000Gustafsson, 2001;Liu et al, 2016;Liu, 2017;Milić et al, 2017).…”