Snow loading (BS6399): Why is the site snow load reduced for altitudes < 100m?
Not version-specific
Tekla Tedds
Tekla Tedds for Word
Environment
British Standard
BS6399-3 cl 6.2 states "Note: for simplicity the calculation it is assumed that the same value for the basic snow load on the ground should apply for altitudes between 0-100m. If preferred the equation for altitudes greater than 100m may be used for altitudes between 0-100m; in these cases the correction term; S_alt (A-100)/100 will automatically be negative."
i.e. You should increase the basic snow load for altitudes >100m but for altitudes < 100m you can either use the default s_b value or opt to use the formula to reduce the site snow load.
Tedds implements the latter option and use the correction term for all altitudes.