Design of fan-shaped staircase

Quick answer：

Fan-shaped staircases are architectural features that incorporate a spiral or curved design, creating a visually appealing and space-saving solution. These staircases are often used in modern and contemporary homes or buildings where a traditional straight staircase would not be as space-efficient. The design considerations include the radius of the curve, the angle of the steps, and the materials used. Safety and accessibility are also crucial aspects to be taken into account during the planning phase.