## 3 Framework Application  
### Case Study  
To show the utility of the framework, a case study pertaining to a residential building in Riyadh, KSA, was conducted. In fact, the Saudi residential market witnessed a significant price increase in the electricity prices starting in 2018 [42], with prices increasing by 260% and 500% for a consumption range of 1-6000 and >6000 Kwh, respectively. The skyrocketed electricity prices pushed residential business owners to rethink their energy consumption and adopt energy retrofitting plans.  
The case study was conducted based on a study period of 20 years, a discount rate of 5%, and covered a residential building (villa), depicted in Figure 1. To construct the 3D model of the residential building and to simulate its energy consumption, BIM Revit 2020 software was used. The residential building is located in the south of Riyadh city, with the following characteristics:  
* The land area is 350 m\({}^{2}\) (3767 ft\({}^{2}\)).
* The total floor area inside the building envelop is 216 m\({}^{2}\) (2325 ft\({}^{2}\)).
* The height of the construction area reaches 10 m (107 feet).
* The villa is north oriented.
* The thickness of the exterior wall is 30 cm (12 inches), and it is built of double blocks walls.
* The gap between the double block wall is filled with 5 cm (2 inches) extruded polystyrene boards (XPS).
* The roof is insulated with 3 cm XPS boards.
* The exterior doors are made of iron that has a thickness of 3 cm (1.2 inches).
* For the exterior fenestration, double glazing aluminum windows are used.  
Despite the high quality of the building envelope, energy consumption is significantly high. The building consumes around 5000 Kwh a month of electrical energy in the summer season. This amount is considered high and heavily affects the electricity bill.  
To generate the different retrofitting plans, retrofitting measures were collected from international energy-efficiency programs, such as LEED v4, BREEAM, the Saudi electricity company, and local Saudi contractors and architects.  
For each retrofitting measure, the components needed to calculate the LCC (purchase cost, maintenance cost, salvage value, etc.) were determined from local Saudi companies, such as Nefal AC Company, Extra, Sheta and Saif, Electro, Almanea, and Saco. The electricity cost, which heavily affects the operational cost, corresponds to the Saudi electricity company tariffs [42]. Since the case study was conducted based on a horizon of 20 years, the inflation rate was considered to calculate the operation, maintenance, and repair costs. According to data from the Saudi Arabian Monetary Authority [43], the inflation rate was within 2-3% in the preceding 10 years, and this rate was considered for all subsequent years in the study period.  
Table 3 shows the LCC calculation, along with yearly cash flows, for the equipment NIKAI Dryer for a discount rate equal to 5%.  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Year** & **Initial Cost** & **M \& O** & **Energy Cost** & **NCF** & **PV Factor** & **PV (in SR)** \\ \hline  
(-\)88 & 603.9635969 & 515.9636 & 0.376889 & 194.4613 \\ LCC & & & & & 7837.422 \\ \hline \end{tabular}
\end{table}
Table 3: NIKAI Dryer LCC calculation.  
Figure 1: Three-dimensional representation of the residential building.