Glossary · Snow and wind
Characteristic snow load S₀
The weight of snow cover per 1 m² of ground exceeded on average once in 50 years; under DBN V.1.2-2:2006 Kyiv has 1,550 Pa.
Ground frame designer
Design the ground frame for your solar plant
Solispec picks the profiles and posts, checks the frame against snow and wind to the DBN and prices it down to the last bolt.
- No sign-up
- Snow and wind check
- Drawings and estimate
Definition
S₀ is the starting figure of every snow calculation. Clause 8.5 of DBN V.1.2-2:2006 defines it as the weight of snow cover on 1 square metre of ground that may be exceeded on average once in 50 years. It is read from the snow zoning map (Fig. 8.1) or from the table of cities in Annex E. The norm also allows S₀ to be derived statistically from snow surveys, where such data exist for the site.
It is a characteristic value, not yet the load a structure is checked for. To get the limit design value, S₀ is multiplied by the reliability factor γfm and by the factor C, which covers the roof shape, the operating conditions and the altitude:
Sm = γfm · S0 · C, C = μ · Ce · CaltExample: Kyiv
For Kyiv, Annex E gives S₀ = 1,550 Pa, roughly 158 kg of snow per square metre of ground. For comparison: Chernihiv 1,720 Pa, Kharkiv 1,600 Pa, Lviv 1,310 Pa, Odesa 880 Pa, Kherson 760 Pa. The north carries more than twice the snow of the south, so a frame designed for Kherson cannot simply be reused in the Chernihiv region.
S₀ is given for the ground, while a panel is tilted, so the load on the module depends on the shape coefficient μ: on a 30° table in Kyiv the limit load on the horizontal projection is 1,329 Pa. The values for every regional centre are on the snow and wind by city page.
How Solispec applies it
The Solispec engine holds the S₀ and W₀ table for the 22 regional centres from Annex E; in the 2026-10-05 audit every value matched the norm. For any other point the nearest regional centre is used. If you have your own S₀ (snow surveys or a client requirement), you can enter it and the engine will use it instead.
Norms and clauses
- DBN V.1.2-2:2006, cl. 8.5, Fig. 8.1, Annex E
- DBN V.1.2-2:2006, formulae (8.1), (8.4)
Related terms
- Limit design snow load SmThe snow load on the horizontal projection used for strength checks: S_m = γ_fm · S₀ · C under DBN V.1.2-2:2006.
- Reliability factor for the limit value γfmThe multiplier on S₀ and W₀ that depends on the mean return period T: 1.00 at 50 years, 1.14 at 100 years (Tables 8.1, 9.1).
- Snow shape coefficient μThe conversion from ground snow to roof snow: μ = 1 up to 25°, 0 from 60°, linear in between (DBN V.1.2-2:2006, Annex Zh, scheme 1).
- Altitude factor CaltThe correction for altitude: 1.4H + 0.3 for snow from 0.5 km, 2H for wind above 0.5 km, otherwise 1 (DBN V.1.2-2:2006).
- Snow and wind zonesThe zones of maps Fig. 8.1 and 9.1 of DBN V.1.2-2:2006; for calculations the S₀ and W₀ values in Pa from the city table are easier to use.
- Characteristic wind pressure W₀The mean wind pressure at 10 m height exceeded on average once in 50 years; Kyiv has 370 Pa under DBN V.1.2-2:2006.
- DBN V.1.2-2:2006 “Loads and actions”: what matters for a solar plantNorms explained
Solispec’s calculation is preliminary: for a design it has to be checked by an engineer. The values and clauses follow the current editions of the norms on the date of the page.