Design of spiral staircase leading to a rooftop

Quick answer：

The design of a spiral staircase leading to a rooftop involves considerations of structural integrity, architectural aesthetics, and safety regulations. It requires selecting the appropriate materials, ensuring sufficient headroom and light, and adhering to local building codes. The staircase should be designed for ease of use, with a comfortable tread width and proper handrail placement. Additionally, the design may incorporate elements like wind bracing for outdoor rooftops to withstand wind loads.