A heavy snow load on the roof represents a special problem, which can cause a collapse. Architectural glazing products are employed in a myriad of situations that require consideration of structural design. Windows, spandrel units, skylights, greenhouses, & passageway all have their own unique requirements for design. These requirements may involve combinations of loads. One of the design requirements of glass used in buildings is to resist the loads created by snow. In the case of overhead glazing, roofs can collapse under a heavy accumulation of snow. To prevent this, it is important to determine the appropriate types & thicknesses of glass. To do so, it is necessary to calculate the weight of potential snow falls. In order to reduce snow load on roofs, special electrically-heated glass can be used to melt the snow gathering on the roof. The selected links present examples, formulas and other useful information about calculating snow load.