Buildings of all types require external fabrics which are capable of facing external exposure conditions while resisting various loads that are incident on them. External conditions include high or low ambient temperatures, high incidence of solar radiation (including ultraviolet rays), attack by environmental media (some of which can be corrosive) and seasonal exposure to rain, snow or sandstorm situations. Loads incident on external fabrics include wind loads, seismic loads, live loads faced during usage of the building and many collateral loads such as loads due to mechanical equipment and services directly mounted on the building fabric.

Buildings of all types require external fabrics which are capable of facing external exposure conditions while resisting various loads that are incident on them. External conditions include high or low ambient temperatures, high incidence of solar radiation (including ultraviolet rays), attack by environmental media (some of which can be corrosive) and seasonal exposure to rain, snow or sandstorm situations. Loads incident on external fabrics include wind loads, seismic loads, live loads faced during usage of the building and many collateral loads such as loads due to mechanical equipment and services directly mounted on the building fabric.