The first floor is converted into a sunken courtyard effect

Quick answer：

Converting the first floor into a sunken courtyard can create a unique and private outdoor space within a building. This design often involves lowering the ground level of the first floor and constructing a garden or courtyard below it. The benefits include increased privacy, better utilization of space, and a more harmonious integration with the surrounding environment. The process typically requires structural engineering assessments to ensure the stability and safety of the building.