FprEN 13031-2
(Main)Greenhouses - Design and construction - Part 2: Greenhouses open to the public
Greenhouses - Design and construction - Part 2: Greenhouses open to the public
This document specifies principles and requirements for the determination of controlled snow loads on the transparent cladding of greenhouses open to the public.
This document can be applied either to the greenhouse or only to the transparent cladding system.
Fire resistance-related aspects are not covered in this document.
Gewächshäuser - Bemessung und Konstruktion - Teil 2: Verkaufsgewächshäuser
Dieses Dokument legt Grundlagen und Anforderungen für die Schätzung kontrollierter Schneelasten auf die transparente Eindeckung von Verkaufsgewächshäusern fest.
Fragen der Feuerwiderstandsdauer werden in diesem Dokument nicht behandelt.
Serres - Calcul et construction - Partie 2 : Serres dans les jardineries ouvertes au public
Le présent document spécifie les principes et exigences applicables à l’estimation de charges de neige régulées sur la couverture transparente de serres ouvertes au public.
Les aspects concernant la résistance au feu ne sont pas traités dans le présent document.
Rastlinjaki: Projektiranje in gradnja - 2. del: Rastlinjaki v vrtnih centrih
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2024
Rastlinjaki: Projektiranje in gradnja - 2. del: Rastlinjaki v vrtnih centrih
Greenhouses: Design and construction - Part 2: Greenhouses in garden centres open to
the public
Gewächshäuser - Bemessung und Konstruktion - Teil 2: Verkaufsgewächshäuser
Serres - Calcul et construction - Partie 2: Serres dans les jardineries ouvertes au public
Ta slovenski standard je istoveten z: prEN 13031-2
ICS:
65.040.30 Rastlinjaki in druge naprave Greenhouses and other
installations
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
prEN 13031-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2023
ICS 65.040.30
English Version
Greenhouses: Design and construction - Part 2:
Greenhouses in garden centres open to the public
Gewächshäuser - Bemessung und Konstruktion - Teil 2:
Verkaufsgewächshäuser
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 284.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13031-2:2023 E
worldwide for CEN national Members.
prEN 13031-2:2023 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 7
5 Snow actions . 9
5.1 General. 9
5.2 Requirements for heated greenhouses with controlled snow loads . 10
5.3 Special heat transmittance (U value according to ISO 4355:2013, Annex D) . 10
o
5.4 Recommendations for the snow load distribution . 13
Annex A (informative) Thermal coefficients C according to ISO 4355:2013, Annex D . 14
t
Annex B (informative) Controlled snow loads according to ISO 4355:2013, Annex F . 19
B.1 General recommendations . 19
B.2 Application for single short-term snowfall events in the Mediterranean . 21
Bibliography . 23
prEN 13031-2:2023 (E)
European foreword
This document (prEN 13031-2:2023) has been prepared by Technical Committee CEN/TC 284
“Greenhouses”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
Part 2 (EN 13031-2) is related to greenhouses open to the public used for the exhibition, presentation
and / or retail of plants.
This Euronorm recognizes the responsibility of each Eurocode Member State and safeguards their right
to determined values related to regulatory safety matters at national level through the use of National
Annexes.
prEN 13031-2:2023 (E)
Introduction
This document relates specifically to greenhouses open to the public, used for the exhibition, presentation
and / or sale of plants, such as greenhouses in garden centers or expositions in botanical gardens. Part 1
of this document is related to commercial production greenhouses used for the professional production
of plants with limited access for authorized personnel only.
The structural design of greenhouses open to the public is carried out using EN 1990 and the relevant
parts of EN 1991 to EN 1999 (Eurocodes 1 to 9) and any further parts, which may follow (e.g. for glass),
regarding the general principles and basic requirements for actions, structural resistance and stability,
serviceability, durability and robustness. National Application Documents (NAD) are considered for each
of the parts.
This document gives additional non-contradictory rules and complementary information for snow
actions on the transparent claddings of greenhouses, where special methods are used, to remove snow
and optimize the transmission of solar radiation, which would otherwise not permit the climate for a
successful growth of plants.
The snow load on the roof can be controlled by removing snow, for example by melting snow with a
system for controlled heating. Controlled snow load is the difference between the initial snow load
expected when heavy snowfall starts, and the snow load removed by a device whose performance is
guaranteed even during heavy snowfall, see ISO 4355. With this document the values for controlled snow
loads can be calculated, taking into account the thermal coefficient C for roof claddings with high thermal
t
transmittance.
For wind loads on greenhouses with multi-span roofs EN 1991-1-4 gives conservative values for pressure
coefficients. In supplement to calculations according EN 1991-1-4, wind tunnel tests and proven and/or
properly validated numerical methods may be used to obtain load and response information.
This document can be applied either to the greenhouse or only to the transparent cladding system.
As long as a structural Eurocode part on glass is not available, it is recommended to specify the glazing
and the relevant design regulations in the National Annex to this part of the standard. For flat glass panels
uniformly loaded perpendicular to their surface, simply supported along the edges and with nominal
thickness not less than 4 mm EN 13031-1 can be used.
National choices are allowed in EN 13031-2 through the following clauses:
— Introduction NOTE: for the glazing and design method for the structural safety of glass panels (as
long as the Eurocode Glass or other regulations (NAD) are not available)
— 5.1 (2) for the estimation of thermal coefficients C < 1
t
— 5.2 (3) for minimum air temperature under the roof for controlled heating
— 5.2 (5) for safety measures for controlled heating
— 5.4 (2) for appropriate snow load distributions for sliding snow on slippery surfaces
National choice is allowed in EN 13031-2 on the use of the informative annexes:
— Annex A for the minimum roof snow load and the calculation of C using the formulae and appropriate
t
limitations
— Annex B for the estimation of C or C based on heat flux, melt rates and snowfall rates
t,0 t
prEN 13031-2:2023 (E)
When no national choice is given, the default choice given in this document can be used. The National
Annex can contain, directly or by reference, further non-contradictory complementary information, in
line with the verbal forms “shall”, “should”, “may” and “can”, as they are used in the Eurocode.
prEN 13031-2:2023 (E)
1 Scope
This document specifies principles and requirements for the estimation of controlled snow loads on the
transparent cladding of greenhouses open to the public.
Fire resistance-related aspects are not covered in this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4355, Bases for design of structures — Determination of snow loads on roofs
EN 673, Glass in building - Determination of thermal transmittance (U value) - Calculation method
EN 674, Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method
EN 675, Glass in building - Determination of thermal transmittance (U value) - Heat flow meter method
EN ISO 6946, Building components and building elements - Thermal resistance and thermal transmittance
- Calculation methods (ISO 6946)
EN ISO 10077-1, Thermal performance of windows, doors and shutters - Calculation of thermal
transmittance - Part 1: General (ISO 10077-1)
EN ISO 10077-2, Thermal performance of windows, doors and shutters - Calculation of thermal
transmittance - Part 2: Numerical method for frames (ISO 10077-2)
EN 1991-1-3, Eurocode 1 - Actions on structures - Part 1-3: General actions - Snow loads
EN 1990, Eurocode - Basis of structural and geotechnical design
EN 1991 (all parts), Eurocode 1: Actions on structures
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1990, EN 1991 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
greenhouse
building structure that optimizes solar radiation transmission used for plants requiring regulated
climatic conditions
3.2
greenhouse open to the public
greenhouse (3.1) used for the professional presentation and / or sale of plants, such as garden centers or
expositions in botanical gardens, where people can have access to certain areas (traffic areas)
prEN 13031-2:2023 (E)
3.3
commercial production greenhouse
greenhouse (3.1) for professional production and / or protection of plants, where human occupancy is
restricted to authorized personnel, concerning low levels in number and duration
Note 1 to entry: Other persons shall be accompanied by authorized personnel.
3.4
transparent cladding
cladding, that allows transmission of solar radiation, required for the growth of plants
Note 1 to entry: Transparent cladding makes snow accumulation visible (impaired solar radiation); immediate
measures can be taken for removal of the snow.
3.5
controlled snow load
difference between the initial snow load expected during a heavy snowfall and the snow load removed
by a device whose performance is guaranteed even during heavy snowfall
3.6
controlled heating
heating operation with devices that are intended and capable of melting and / or removing an amount of
snow, to limit the roof snow load as fast as required
Note 1 to entry: Requirements for greenhouse heating and safety (back up) are given in 5.2 and can be further
specified in the National Annex, dependent on the local snow climate, experience, and state of the art for technical
equipment.
4 Symbols and abbreviations
Abbreviations:
NAD National Application Documents, e.g. National Annex to Eurocode, also National Code or
Standard or National Regulation of an Authority
SWE Snow Water Equivalent
Symbols:
NOTE The following symbols used in this document are based on EN 1990 and EN 1991.
Latin upper-case letters:
C exposure coefficient
e
C special exposure coefficient for controlled snow loads
e,c
C thermal coefficient
t
C basic value of the thermal coefficient (without roof angle influence f(α))
t,0
L latent heat of fusion of water (for ice, snow) in kJ/kg at melt temperature θ = 0,01 °C
f s,m
L , corrected latent heat of fusion in kJ/kg including the warming of snow
f c
Q
energy flux density (rate) in W/m from the warm roof below to the melt layer
o
Q
energy flux density (rate) in W/m from the air outside via the snow to the melt layer
s,e
prEN 13031-2:2023 (E)
R
thermal resistance of a component in m K/W
T
R
internal surface resistance (surface to internal air) in m K/W
si
R
internal surface resistance for heat flow sideways in m K/W
si,sw
R
internal surface resistance for heat flow upwards in m K/W
si,up
R
external surface resistance (surface to external air) in m K/W
se
R
thermal resistance of the material layer j in m K/W
λ,j
R
thermal resistance of the frame, e.g. gladding bars and gutter, in m K/W
f
R
...
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