Tensegrity greenhouse: An innovative covering structural system with low shading

Based on the structural principle of “Tensegrity” (tensional integrity), an innovative typology of greenhouse was developed. The principle behind the study uses structural elements of small sections (bars and cables) and employs compressed elements included in a network of tensioned elements. The innovative greenhouse structure allows covering larger spans than the most common greenhouse typologies on the market, improving the surface area usable for crops and reducing the structural sections. The present research focuses on the evaluation of the shading caused by the structural elements inside the tensegrity greenhouse, compared with the most common commercial typologies. At this aim, simulations of illuminance factor (IF) at different distance from the ground level were assessed by means of Revit, a software for building information modelling (BIM), developed by Autodesk Inc., which allows analyzing the impact of natural light and shadows on the interiors of buildings. The IF of the tensegrity greenhouse model (TGM) was compared with the one calculated for different greenhouse typologies (planar pitched roof and vaulted roof) having the same area (118.75 m2) and height of the gutter (3.5 m) placed in Rome (Italy). For all kind of greenhouses, the daily variation of the IF was evaluated in two representative days of the year: June 21 and December 21. As result, the TGM showed a value per square meter of the IF Higher than about 20% compared to traditional structures.