Effects of Balconies on the Wind Loading of a Tall Building

Balconies are a common architectural feature on mid- and high-rise buildings. The presence of balconies alters the interaction of the wind with the building façade, and thereby the resulting cladding and structural loads. Much of the aerodynamic data which comprise wind loading codes (i.e., ASCE 7, NBCC) are based on prismatic buildings with no external features. This case is generally considered to provide an upper bound, as the aerodynamics of the overall building geometry will be clean and well-correlated with height. With advances in modelling capabilities in previous years, the inclusion of balconies and other minor external features on wind tunnel test models has become more achievable and thus is of interest in determining the final wind loads and responses for the building, as well as determining reductions that may exist from code-specified values. A challenge that exists for wind engineers is that occasionally balconies may be added, removed, or modified as the design of the project progresses (or after the initial wind tunnel test has been performed). This paper discusses the impacts of balconies on the overall wind loads and responses for a unique building to illustrate some of the differences between external geometries with and without balconies.