BS EN 1991-1-4:2026

1.1 Scope of EN 1991-1-4 (1) This document gives rules for the determination of natural wind actions for the structural design of building and civil engineering works for each of the loaded areas under consideration. This includes actions applied to the whole structure or parts of it, as well as wind-exposed elements attached to the structure. (2) This document is applicable to: - buildings and other civil engineering works with heights up to 200 m; - guyed masts, other open lattice structures and chimneys with heights up to 300 m; - bridges having no span greater than 200 m. (3) The rules contained in this document allow the evaluation of characteristic wind actions on land-based structures. (4) This document is applicable to offshore coastal structures. NOTE Additional or amended provisions can be necessary. (5) This document does not give guidance on non-synoptic winds (e.g. thunderstorms, downbursts, microbursts, tornadoes, etc.), mixed wind climates, nor does it give guidance on how to account for local effects (e.g. thermal effects, funnelling, strong arctic thermal surface inversion, etc.). (6) This document addresses simplified procedures for dynamic effects, mostly based on the assumption of a dominant single-mode response (see Annex E, Annex F and Annex G). General criteria for performing a full dynamic analysis under aerodynamic excitation are not treated in this document. (7) Wind pressure effects of passing vehicles are outside the scope of this document. NOTE See EN 1991 2 for wind effects from passing trains. 8) This document also provides guidance on wind tunnel testing and numerical modelling which can be needed or desirable when the shape or structural behaviour are unusual or do not strictly fall within the rules of the document, or in cases of unusual orography or other surroundings. 1.2 Assumptions (1) The assumptions given in EN 1990:2023, 1.2 apply.