This thesis has been aiming to design a light-weight, structurally safe, and engineering practical pretensioned roof structure. Firstly literature study has been performed to gain insight about the application of tensegrities as roof structures. With some programming and scripting skills some special components based on the Grasshopper environment have been developed to combine the FEM software with Grasshopper to achieve the goal for parametric design. Based on the parametric model a lot of designs and analysis have been performed and the influences of changing the possible design variables in this roof structure have been found. There are always three variables studied at the same time. This research work also proved that it is possible to use software to optimise the structure automatically by defining all the load cases and boundary conditions. After getting the final design, three modes have been simulated to evaluate the redundancy of this roof structure.