5. External factors

5.1 Snow

• Exceptional falls

  In principle, the NV 65 and N 84 rules cover all regions of France for even the most exceptional snowfalls (extreme snow) likely to occur. However, precipitation can sometimes exceed the forecast values.

• Accumulation

  The phenomenon of snow accumulation poses a delicate problem for the designer. Regulations provide guidance on possible accumulations, but cannot anticipate every possible case. Estimates of specific loads may, in some cases, be necessary.