{"id":17773,"date":"2026-11-07T20:43:59","date_gmt":"2026-11-07T19:43:59","guid":{"rendered":"https:\/\/ventsystems.de\/lexikon\/formbeiwert-schneelast\/"},"modified":"2026-11-07T20:43:59","modified_gmt":"2026-11-07T19:43:59","slug":"formbeiwert-schneelast","status":"publish","type":"page","link":"https:\/\/ventsystems.de\/en\/lexikon\/formbeiwert-schneelast\/","title":{"rendered":"Shape coefficient (snow load)"},"content":{"rendered":"

The Shape coefficient<\/strong> (\u03bc) converts the snow load on the ground into the load on a roof. It depends mainly on the roof pitch: snow slides off steep roofs and stays on flat ones.<\/p>\n\n\n

Values for simple roofs<\/h2>\n\n\n
Roof pitch<\/th>Shape coefficient \u03bc<\/th><\/tr><\/thead>
0\u00b0 to 30\u00b0<\/td>0,8<\/td><\/tr>
30\u00b0 to 60\u00b0<\/td>decreases linearly from 0.8 to 0<\/td><\/tr>
ab 60\u00b0<\/td>0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n

Based on DIN EN 1991-1-3 with national annex. Other values apply to special cases such as snow drifts at higher parts of a building; these are determined by the structural engineer.<\/p>\n\n\n

Example<\/h2>\n\n\n

Ground snow load 0.85 kN\/m\u00b2, skylight on a flat roof: 0.8 \u00d7 0.85 = 0.68 kN\/m\u00b2, i.e. about 680 N per m\u00b2. A 1.2 \u00d7 1.2 m sash thus carries just under 1,000 N of snow, of which the actuator carries about half.<\/p>\n\n\n

In the calculator<\/h2>\n\n\n

In Window actuator calculator<\/a> you enter the snow load on the roof for the window type \u201croof window\u201d, i.e. the value after applying the shape coefficient.<\/p>\n\n\n

Read more<\/h2>\n\n\n