## 4 Results
### Base Case Performance  
Figure 4 illustrates the monthly cooling energy consumption for the base case, with peak demand occurring between May and October. This surge is attributed to a significant increase in heat gains through the building envelope. The highest recorded heat gains for walls and glazing reached 10,366.79 kWh and 4997.64 kWh, respectively. Improving the thermal performance of the building through facade retrofitting could, therefore, result in substantial electricity savings. To explore this further, on-site measurements were conducted to assess the current state of facade heat gains. The area-weighted average surface temperature and heat leakage were calculated using a FLIR ThermaCAM B20 thermal camera. These measurements were taken on 5 September 2023, between 2:30 p.m. and 3:00 p.m.  
\begin{table}
\begin{tabular}{c c c} \hline
**Strategy Code** & **Strategy Description** & **Cost [SAR/m2]** \\ \hline \multicolumn{3}{c}{**A. External Walls**} \\ \hline S-WA-1 & VF with ACP sheet cladding & 430 \\ \hline S-WA-2 & VF with FC & 200 \\ \hline S-WA-3 & ETICS & 150 \\ \hline S-WA-4 & Prefabricated wood & 450 \\ \hline S-WA-5 & VF with limestone cladding & 380 \\ \hline S-WA-6 & VF with sandstone cladding & 430 \\ \hline S-WA-7 & VF with AAC brick cladding & 240 \\ \hline S-WA-8 & VF with WPC cladding & 340 \\ \hline \multicolumn{3}{c}{**B. Windows**} \\ \hline S-W-1 & Smart glass (electrochromic) & 1200 \\ \hline S-W-2 & Low-e coating & 250 \\ \hline S-W-3 & Triple-glazed & 320 \\ \hline S-W-4 & Double-glazed with Argon & 20 \\ \hline S-W-5 & Smart glass with Argon & 1220 \\ \hline S-W-6 & Low-e coating with Argon & 270 \\ \hline S-W-7 & Triple-glazed with Argon & 340 \\ \hline \multicolumn{3}{c}{**C. Shading Devices**} \\ \hline S-S-1 & Smart electric blinds & 800 \\ \hline S-S-2 & Window louver & 300 \\ \hline S-S-3 & Overhang-wood & 400 \\ \hline S-S-4 & Overhang-metal & 750 \\ \hline \end{tabular} AAC = Autoclaved Aerated Concrete, ACP = Aluminum Composite Panel, ETICS = External Thermal Insulation Composite Systems, FC = Fiber Cement Board, VF = ventilated Facade, WPC = Wood Plastic Composite.  
\end{table}
Table 4: Estimated cost of the proposed facade retrofit strategies in the Saudi construction market.  
Figure 5 displays the thermal images obtained during the analysis. The facade temperature anomalies were categorized into five zones: v1, v2, v3, v4, and v5. For both the external walls and windows, the area-weighted average surface temperature was calculated based on the area of each respective zone. The average temperatures were determined using Equation (2), which outlines the process for calculating the area-weighted average surface temperature:  
\[\text{V}=\sum\text{v}_{\text{n}}.\text{ A}_{\text{n}}/\text{A}_{\text{t}} \tag{2}\]  
where v\({}_{\text{n}}\) is zone temperature (\({}^{\circ}\)C), A\({}_{\text{n}}\) is zone area (m\({}^{2}\)), and A\({}_{\text{t}}\) is total surface area (m\({}^{2}\)).  
The results revealed that the external walls exhibited an average surface temperature of 53.96 \({}^{\circ}\)C, while the windows had a similar average temperature of 53.82 \({}^{\circ}\)C. An anomaly was detected at the connection areas between the walls and floors, where lower surface temperatures were recorded, suggesting potential heat leakage. Additionally, the windows displayed higher surface temperatures on the glass compared to their surroundings, contributing to significant heat gains and an increase in indoor temperature. The elevated surface temperatures across the facade were primarily attributed to the construction materials, with the external walls being composed of precast concrete and the windows utilizing uninsulated glass.