Due to various constraints of having individual housing units, people tend to prefer apartments. Generally, these apartments are of single storey nature with up market apartments called penthouses having two floors with an internal staircase to approach the upper floor. However, in tropical climatic conditions, it is preferable to have apartments adopting this penthouse model since it allow having more balconies with better ventilation and also allow a greater degree of privacy. In this research, the feasibility of using a light weight panel of 65 mm thickness for the construction of a staircase has been evaluated experimentally. The reason for using the light weight panel is that it allows the formation of a staircase where the space underneath can be readily converted to a store-room. This will be very useful in compact houses where the space utilization has to be brought to a very high level.