# Building Energy Retrofit Measures in Hot-Summer-Cold-Winter Climates: A Case Study in Shanghai
## 4 Building Retrofit Measures and Major Affecting Elements in Shanghai  
Building retrofitting is defined as the modification of existing building with facilities or equipment for ease of operation, improvement of efficiency and reduction of environmental disturbance [52]. It includes specific methods such as an upgrade of the building envelope, improvement of mechanical systems, operating and management practices while sustaining a comfortable indoor environment for the occupants [53]. The selective implementation of specific retrofit measures also enhances the environmental impact, economics, as well as the energy efficiency of buildings. These measures are designed to suit the building characteristics and reduce the adverse effect of climate variation on the comfort level of the building. By enhancing building energy savings, greenhouse gas (GHG) emissions are also reduced.  
Generally, building retrofit measures are categorised into five major aspects: Building envelope, equipment system, new technology updates (renewable energy sources), energy-conserving behaviours and energy management and control systems. However, based on the management structure, building retrofit measures are classified into three major groups: Demand-side, supply-side and energy conservation (also known as the human factor) [16]. Details of general retrofitting technologies and their classifications can be found in the following studies [9; 54; 55; 56] and are summarised in Table 3. The application and effectiveness of these measures depend primarily on the building typology and its characteristics. Other notable factors include geographical location and its associated climatic variations.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Building Retrofit Classification** & **Building Retrofit Measures** \\ \hline \multirow{8}{*}{Demand-side Management} & - & Building fabric insulation (i.e., ceiling, wall, etc.) \\  & - & Windows retrofits (i.e., multiple glazing, low-E coatings, shading systems, etc.) \\  & Building Envelope & - & Airtightness \\  & - & Cool roofs and coatings \\  & - & Floor retrofits, etc. \\ \cline{2-3}  & & - & Natural ventilation \\  & Equipment System & - & Control upgrade \\  & & - & Lighting upgrade \\  & & - & Energy-efficient equipment (HVAC, water heating, lift, etc.) \\  & & - & Thermal storage and heat recovery, etc. \\ \hline \multirow{8}{*}{Energy Conserving BEAviors} & - & Occupancy regimes, schedules and activities \\  & Energy Conserving Behaviors & - & Comfort requirements \\  & & - & Staff training \\  & & - & New management scheme \\  & & - & Monitoring strategies, etc. \\ \cline{2-3}  & Energy Management and Control System & - & Management and maintenance (i.e., review service systems, energy sourcing, utility rate structure, etc.) \\ \cline{2-3}  & Energy Management and Control System & - & Access to control (i.e., automatic control systems, optimization control strategies, etc.) \\ \cline{2-3}  & & - & Solar PV/PVT systems \\  & & - & Solar thermal systems \\ \cline{2-3}  & & - & Biomass systems \\ \cline{2-3}  & & - & Electric system retrofits \\ \cline{2-3}  & & - & Geothermal systems \\ \cline{2-3}  & & - & Wind power systems, etc. \\ \hline \hline \end{tabular}
\end{table}
Table 3: General building retrofit measures and classification (Adopted from [16]).