SIST EN 1991-1-4:2026/oprA1:2026

• Abstract:

  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 1990-1:2023+A1:2026, 1.2 apply.

• Status: Not Published
• Public Enquiry End Date: 29-Oct-2026
• ICS: 91.010.30 - Technical aspects
• Technical Committee: KON - Structures
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 21-Aug-2026
• Due Date: 08-Jan-2027
• Ref Project: EN 1991-1-4:2026/prA1 - Eurocode 1 - Actions on structures - Part 1-4: Wind actions

• Amends: kSIST FprEN 1991-1-4:2025 - Eurocode 1 - Actions on structures - Part 1-4: Wind actions
• Effective Date: 06-May-2026

Overview

SIST EN 1991-1-4:2026/oprA1:2026 (Eurocode 1 - Actions on structures - Part 1-4: Wind actions) is a key European standard developed by CEN that provides comprehensive guidance for the determination and modelling of wind actions on structures. The aim of this standard is to ensure structural safety and reliability for buildings and civil engineering works subject to wind loads. SIST EN 1991-1-4:2026/oprA1:2026 is applicable to a wide range of structures, including buildings up to 200 m in height, guyed masts and lattice structures up to 300 m, and bridges with no span greater than 200 m. The document also provides guidance for preliminary design of taller buildings and civil engineering projects, and covers specialized advice for offshore coastal structures and wind tunnel testing where non-standard conditions apply.

Key Topics

• Scope of Wind Actions: The standard details procedures to evaluate natural wind actions for structural design across different types of buildings and civil engineering works.
• Applicability and Limitations:
  • Suitable for structures on land and certain offshore applications.
  • Specifies height and span limitations for different structures.
  • Excludes guidance for non-synoptic winds (e.g., thunderstorms, tornadoes) and certain complex local effects.
• Modelling of Wind Loads:
  • Guidance on pressure and force coefficients, taking into account terrain, structure geometry, and exposure.
  • Methods for the assessment of characteristic wind actions and dynamic effects, with reference to dominant single-mode response assumptions.
• Annex Provisions:
  • Annexes A–I: Cover specific factors like terrain effects, pressure coefficients, dynamic response procedures, and guidance for slender and lattice structures.
  • Guidance on interpreting pressure zones, dynamic response, canopies, silos, tanks, and more.
• Wind Tunnel Testing and Numerical Modelling:
  • Recommendations for when such methods are needed for unusual building shapes or sites with atypical wind exposure.
• National Annexes:
  • Room for Member States to define national values relevant to safety, accommodating local wind climates and regulations.

Applications

The practical value of SIST EN 1991-1-4:2026/oprA1:2026 is significant in the fields of structural engineering, architecture, and infrastructure design. Typical applications include:

• Structural Design for Wind Loads: Ensuring buildings, towers, chimneys, and bridges are safely designed to resist wind forces according to consistent European standards.
• Civil Engineering Works: Applicable to infrastructure projects where wind actions have a critical safety or operational impact.
• Preliminary and Detailed Design Phases: The standard supports both early-stage concept planning and final structural detailing, with explicit provisions for projects up to specified heights and spans.
• Specialized Assessment for Complex Projects: Guidance for wind tunnel testing and advanced analysis for tall buildings, slender structures, or those in complex terrain or near coastlines.
• Regulatory Compliance: Helps designers and engineers ensure that their projects meet European safety and reliability requirements, with the ability to adapt for national considerations via National Annexes.

Related Standards

Implementing SIST EN 1991-1-4:2026/oprA1:2026 often involves coordinated use with related European and international standards, including:

• EN 1990-1:2023+A1:2026: Basis of structural design; sets forth key assumptions and principles, referenced throughout this standard.
• EN 1991-1-2: Addresses thermal actions on structures.
• EN 1991-2: Concerns actions on structures from moving loads, such as wind pressure effects due to passing trains and vehicles.
• Relevant Execution, Material, and Product Standards: Specific requirements for material performance and testing as cited in project specifications.
• National Annexes: Country-specific adaptations reflecting local wind climate and regulatory requirements.

By integrating SIST EN 1991-1-4:2026/oprA1:2026 into project workflows, engineers and architects demonstrate compliance with best practices for wind action assessment and contribute to the safety and durability of the built environment.

SLOVENSKI STANDARD
01-oktober-2026
Evrokod 1 - Vplivi na konstrukcije - 1-4. del: Vplivi vetra
Eurocode 1 - Actions on structures - Part 1-4: Wind actions
Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-4: Windlasten
Eurocode 1 - Actions sur les structures - Partie 1-4 : Actions du vent
Ta slovenski standard je istoveten z: EN 1991-1-4:2026/prA1
ICS:
91.010.30 Tehnični vidiki Technical aspects
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
EN 1991-1-4:2026
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
July 2026
ICS
English Version
Eurocode 1 - Actions on structures - Part 1-4: Wind actions
Eurocode 1 - Actions sur les structures - Partie 1-4 : Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-4:
Actions du vent Windlasten
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 250.

This draft amendment A1, if approved, will modify the European Standard EN 1991-1-4:2026. If this draft becomes an
amendment, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
inclusion of this amendment into the relevant national standard without any alteration.

This draft amendment was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1991-1-4:2026/prA1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modification throughout the whole document . 4
2 Modification to European Foreword . 4
3 Modification to “Introduction” . 4
4 Modification to Clause 1, “Scope” . 4
5 Modification to Clause 3, “Terms, definitions and symbols” . 4
6 Modification to Clause 5, "Modelling of wind actions" . 4
7 Modification to Clause 6, "Wind velocity and velocity pressure” . 4
8 Modification to Annex A, “Terrain effects” . 5
9 Modification to Annex B, “Pressure coefficients for pressures on surfaces” . 5
10 Modification to Annex C, “Net pressure coefficients and force coefficients for
canopies” . 11
11 Modification to Annex D, “Force coefficients and friction coefficients” . 12
12 Modification to Annex E, “Procedure for along-wind dynamic response” . 13
13 Modification to Annex F, “Procedure for across-wind and torsional actions on
susceptible buildings” . 15
14 Modification to Annex G, “Procedure for across-wind dynamic and aeroelastic
response of slender structures” . 15
15 Modification to Annex H, “Dynamic characteristics of structures with linear elastic
behaviour” . 15
16 Modification to Annex I, “Response of steel lattice towers and guyed masts” . 15

European foreword
This document (EN 1991-1-4:2026/prA1:2026) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible for all
Structural Eurocodes and has been assigned responsibility for structural and geotechnical design matters
by CEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1991-1-4:2026.
NOTE Some modifications are purely editorial corrections to improve the quality of the document and these will
not be tagged in the consolidated publication, as noted after the modification.
The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part
of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to
CEN by the European Commission and the European Free Trade Association.
The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product
and test standards, and to identify requirements for execution, materials, products and testing that are
relied upon by the Eurocodes.
The Eurocodes recognise the responsibility of each Member State and have safeguarded their right to
determine values related to regulatory safety matters at national level through the use of National
Annexes.
1 Modification throughout the whole document
Modify the symbol for the kinematic viscosity of the air “ν” to “ν ”.
air
2 Modification to European Foreword
Add the word “structures” between “slender” and “with” in list item a).
Add “guidance on” between “of” and “an” in list item c).
3 Modification to “Introduction”
0.5 Add the following references in the table with national choices: "B.3.1(1) - 2 choices" and "D.8.1(6)".
0.5 Replace in the table with national choices “B.3.1(3)" with "B.3.1(2)".
0.5 Replace in the table with national choices "B.3.1(5) - 2 choices" with "B.3.1(5)".
4 Modification to Clause 1, “Scope”
1.1(2) Delete the word “other” in the first list item.
1.1(2) Add a new second list item: “preliminary design stage of buildings and civil engineering works with
heights up to 300 m;”
1.1(2) Add the following note below the list: “NOTE For wind profiles up to 300 m, see Annex A.”
5 Modification to Clause 3, “Terms, definitions and symbols”
3.2.2 Delete the word “natural” in the definition of the symbol n .
x
6 Modification to Clause 5, "Modelling of wind actions"
5.4(10) Modify the symbol “b” to “d” in Formula (5.1) and in the definition below the formula.
5.4(11) Replace the word “may” with “can” in the list items a) and b).
5.4(11) Delete “, they should be” in list item c).
7 Modification to Clause 6, "Wind velocity and velocity pressure”
6.2(7) Replace Note 1 with "NOTE 1 For a Gumbel distribution (see Annex L), the shape parameter K is equal
to β/α, where α is the corresponding location parameter and β is the corresponding scale parameter."
6.3.2(1) Delete the word “permanent” in Table 6.1.
6.3.2(1) Replace “x ” with “x” in Formula 6.8.
s
6.3.2(3) Replace “nominal angular sector” with “nominal direction” in the key to Figure 6.1.
6.3.2(3) Replace “2” with “x”, “3” with “2” and “4” with “3” in the key to Figure 6.1.
6.3.2(3) Replace Figure 6.1 with the following new Figure:

8 Modification to Annex A, “Terrain effects”
A.3(1) Add “and civil engineering works or forest,” between the words “buildings” and “and” in the
description of terrain category IV in Figure A.1.
A.4(10) Replace “3,5” with “5,0” in Formula (A.9).
A.4(10) Replace “log” with “log ” in Formula (A.10) to Formula (A.13).
A.4(11) Replace “it” with “the factor s ”.
o
A.4(11) Replace “s = A in Formula (A.5)” with “s = A given by Formula (A.6)”.
o
A.7.1(2) Replace “A.7.2 should be substituted for 6.3.2 and A.7.3 should be substituted for 6.4” with “6.3.2
should be substituted by A.7.2 and 6.4 should be substituted by A.7.3”.
9 Modification to Annex B, “Pressure coefficients for pressures on surfaces”
B.3.1(1) Delete “, which is the area of the surface,”.
B.3.1(1) Add “, c , c and“ between “coefficients” and “c ”.
pe1 pe10 peA
B.3.1(1) Add “in this Annex” in the end of the note which is numbered Note 1.
B.3.1(1) Add the following three new notes after the existing NOTE
“NOTE 2 External pressure coefficients given in this Annex are the most unfavourable values obtained in a
range of wind angles θ = ±45° either side of the relevant orthogonal direction, to be used unless the National Annex
gives different values to cover alternative ranges of wind angles.
NOTE 3 The procedures for effect of the size of the loaded area are as given in this Clause B.3, unless the National
Annex gives different procedures.
NOTE 4 The external global pressure coefficients and external local pressure coefficients can produce symmetric
load patterns. The asymmetry of the action on the vertical surfaces arising when θ ≠ 0° is covered by B.3.1(6). The
asymmetry of the action on the roof surfaces arising when θ ≠ 0° is accounted for by the large values of the pressure
coefficients in zone F in B.3.3 through B.3.6.”
Replace “NOTE” with “NOTE 1“.
B.3.1(2) Replace “should” with “may”, and add in the end of the paragraph (before the note): “, when the
total surface area contributing to the wind actions, is larger than A = 50 m .”.
B.3.1(2) Number the existing NOTE as NOTE 3, and add the following new notes beforehand:
“NOTE 1 External global pressure coefficients are given in Clause B.3, unless the National A
...