The office environment has a tremendous impact on employees’ health, productivity and well-being. Considering the fact that employees stay in their offices for a prolonged time, which can extend to more than ten hours in many cases, the office indoor environmental quality (IEQ) can either cause serious health issues or restore the employee's health. Similar to green building rating systems, WELL® Standards have been established to focus solely on the indoor environmental quality. A case study was conducted for a selected office space to assess the office IEQ against WELL® Standards and evaluate the office performance under different WELL® Concepts. For this purpose, a survey was first conducted for the employees in the space under study. This was followed by obtaining actual measurements for the current indoor environment, investigating possible improvements and applying the appropriate improvements. After applying those improvements, the space was reassessed against WELL® Concepts and another survey was conducted to finalize a case study for indoor environmental quality.