## 2 Simulation Environment and Introduction of Case Buildings  
### Basic Information about the Five Selected Cities  
As mentioned above, China is classified into five different climate regions, namely the Severe Cold Region, Cold Region, Hot-Summer Cold-Winter Region, Hot-Summer Warm-Winter Region, and Temperate Region, which are established to accommodate the thermal-technical design of buildings in China. In this paper, in order to evaluate the energy performance of RC, timber, and straw buildings, five major cities in the Cold and Severe Cold regions of China were selected to provide the building simulation environment. Each city is located in a different climate sub-region (Figure 4). The basic location and climatic information for the five study cities are presented in Table 1 and Figure 4.  
Buildings in the Cold and Severe Cold regions have to follow local construction regulations which define the structural criteria, the insulation properties for opaque walls floors and roofs, and the thermal and optical performance of windows and skylights. Amongst these regulations, thermal insulation is one of the most important factors and is enforced strictly due to the low external temperatures in winter. The basic thermal design parameters are presented in Table 2.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Climate Zones** & **Detailed Partition** & **City** & **Basis for Partition** \\ \hline \multirow{4}{*}{Severe Cold} & I(A) & Hailar & \(6000\leq\) HDD18 \\  & I(B) & Harbin & \(5000\leq\) HDD18 \(<6000\) \\  & I(C) & Urumchi & \(3800\leq\) HDD18 \(<5000\) \\ \hline \multirow{2}{*}{Cold} & II(A) & Lanzhou & \(2000\leq\) HDD18 \(<3800\), CDD26 \(\leq 90\) \\  & II(B) & Beijing & \(2000\leq\) HDD18 \(<3800\), CDD26 \(>90\) \\ \hline \end{tabular} Data Source: Design Standard for Energy Efficiency of Residential Buildings in Severe Cold and Cold Zones (JG) 26-2010). HDD18: Heating degree days based on 18 \({}^{\circ}\)C, CDD26: Cooling degree days based on 26 \({}^{\circ}\)C.  
\end{table}
Table 1: Data for the five study cities.  
Figure 4: Location of the five study cities.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Climate Regions** & **Detailed Partition** & **City** & \begin{tabular}{c} **Heating Period** \\ **(Days)** \\ \end{tabular} & \begin{tabular}{c} **Heating** \\ **Load** \\ **(W/m\({}^{2}\))** \\ \end{tabular} & \begin{tabular}{c} **U-Value [W/m\({}^{2}\) (K]]** \\ **[m\({}^{2}\)-K]/W]** \\ \end{tabular} & \begin{tabular}{c} **R** \\ **[m\({}^{2}\)-K]/W]** \\ \end{tabular} \\  & I(A) & Hailar & 206 & 18.9 & \begin{tabular}{c} Rod: \(\leq\)0.25 \\ Wall: \(\leq\)0.50 \\ Window: \(\leq\)2.2 \\ Door: \(\leq\)1.5 \\ Rod: \(\leq\)0.30 \\ Wall: \(\leq\)0.55 \\ Window: \(\leq\)2.2 \\ Door: \(\leq\)1.5 \\ Door: \(\leq\)0.40 \\ Wailt: \(\leq\)0.60 \\ Window: \(\leq\)2.2 \\ Door: \(\leq\)2.5 \\ \end{tabular} & \begin{tabular}{c} Rod: \(\leq\)0.25 \\ \(\geq\)1.0 \\ \(\geq\)1.5 \\ \(\geq\)0.30 \\ \end{tabular} & \begin{tabular}{c} **R** \\ **[m\({}^{2}\)-K]/W]** \\ \end{tabular} \\  & I(B) & Harbin & 167 & 18.3 & \begin{tabular}{c} Rod: \(\leq\)0.45 \\ Wall: \(\leq\)0.70 \\ Window: \(\leq\)2.8 \\ Door: \(\leq\)2.0 \\ Door: \(\leq\)0.45 \\ \end{tabular} & \begin{tabular}{c} **R** \\ **[m\({}^{2}\)-K]/W]** \\ \end{tabular} \\  & I(C) & Urumchi & 149 & 17.4 & \begin{tabular}{c} Rod: \(\leq\)0.45 \\ Wall: \(\leq\)0.70 \\ Window: \(\leq\)2.8 \\ Door: \(\leq\)2.0 \\ Door: \(\leq\)0.45 \\ \end{tabular} & \begin{tabular}{c} **R** \\ **[m\({}^{2}\)-K]/W]** \\ \end{tabular} \\  & I(C) & Urumchi & 149 & 17.4 & \begin{tabular}{c} Rod: \(\leq\)0.45 \\ Wall: \(\leq\)0.70 \\ Window: \(\leq\)2.2 \\ Door: \(\leq\)2.0 \\ Door: \(\leq\)0.45 \\ \end{tabular} & \
\begin{tabular}{c} **R** \\ **[m\({}^{2}\)-K]/W]** \\ \end{tabular} \\  & II(A) & Lanzhou & 126 & 13.1 &
\begin{tabular}{c} Rod: \(\leq\)0.45 \\ Wall: \(\leq\)0.70 \\ Window: \(\leq\)2.8 \\ Door: \(\leq\)2.0 \\ Door: \(\leq\)0.45 \\ Door: \(\leq\)0.70 \\ Door: \(\leq\)0.