The improved performance of hip roofs in extreme winds — A case study

Abstract Whilst the gable roof comprises a majority of architectural form on engineered low buildings, the residential low building, which is generally subject to deemed-to-comply building regulations, is typified by a myriad of roof shapes. These must influence the wind loads imparted on the structure. Post disaster studies have revealed that similar standards of residential low rise construction of different geometric forms have suffered a disparity in wind-induced damage. In particular high roofs have enjoyed better performance in extreme winds compared to similarly constructed gable roof dwellings. The improved performance of the hip roof over the gable roof appears to be primarily due to the reduced aerodynamic loads and the spatial distribution of these loads. This paper provides an overview of the hip/gable performance disparity and wind tunnel investigation, reviews the performance of a particular hip roof development and suggests benefits of incorporating hip roof lines in the buildings constructed in cyclone or hurricane prone areas.