Snow load is a primary imposed action for UK roof structures, varying significantly by geographic location and altitude. Rooftop solar arrays can affect snow accumulation patterns: flat or low-tilt arrays may accumulate more snow than the bare roof, while steep arrays may shed snow onto lower roof sections, creating localised concentrated loads.
Ground snow load values across the UK are defined in the UK National Annex to EN 1991-1-3, with altitude correction applied for sites above 100 m. For commercial solar PV pre-construction, snow load is combined with dead load and wind load in Eurocode load combination expressions to produce the governing design load for structural utilisation checks.