Snow loads play a major role in overload situations and collapses of building structures, so the necessity of an accurate snow load may be vital. The combination of wind action and snow loads may govern the design of some structures. Testing geometry and effects of local shelters in the wind tunnel can lead to a nuanced and accurate picture of the specific snow loads.
Wind tunnel tests are done using visual tests e.g. flow visualization by helium bubbles or glass beads and measurement tests where the wind velocities are measured on scale models.
Svend Ole Hansen is chairman of the code committee revising the Eurocode EN 1991-1-3 on snow loads.