Abstract
The Kingdom of Saudi Arabia is working to establish cities based on the economy and attract investments such as Neom and The Line. Moreover, at the beginning of 2021, the Saudi government announced that it will stop dealing with foreign companies that establish regional offices outside the country, starting from the beginning of the year 2024. These acts will contribute to strengthening the presence of office buildings significantly. However, the biggest challenge is the inefficient energy design and operation of the existing office buildings in an overheated environment. Therefore, improving the thermal performance of existing office buildings has become a priority for sustainable development. This study aims to evaluate the current scenario of energy performance in Saudi governmental office buildings. One of the most important strategies of the Kingdom's vision 2030 regards energy conservation. In support of the aim of this research, the annual electric energy bill of the Agricultural Development Fund building in Najran has been collected and analyzed. Accordingly, the analyses were carried out to evaluate the improvement in energy consumption through retrofitting the building envelope. DesignBuilder simulation program was used to investigate the effects of different retrofitting strategies of the building envelope in terms of changing the type of window's glass, adding thermal insulation layers, and applying egg-crate shading devices. The results reported that applying a combination of those strategies reduced total energy consumption by 26.81% compared with the current base case.