In most areas with a temperate climate, there is a lot of snowfall in winter. Some of the snow will accumulate on the roof of the house and if the weather is very cold, the layer of snow on the roof could be several feet deep.
Most home owners allow some snow to accumulate on the roof since the snow provides additional insulation for the house. It prevents heat escaping from the house to the external environment and reduces the heating bill. However, after a certain stage, the weight of the snow could create additional pressure on the roof of the house . The roof may develop cracks and break after some time.
Though roofs in these areas which receive a lot of snowfall in winter are designed to withstand the additional weight caused by the accumulation of snow, it is advisable to remove the additional snow after the layer formed is more than 2 feet thick. Not much additional insulation is provided by the additional thickness of the snow. Also, if it rains, the snow absorbs the water and increases the weight on the roof.