CEN ISO/TR 52016-4:2024

SLOVENSKI STANDARD
01-januar-2025
Energetska učinkovitost stavb - Potrebna energija za ogrevanje in hlajenje,
notranje temperature ter zaznavna in latentna toplotna obremenitev - 4. del:
Obrazložitev in utemeljitev ISO 52016-3 (ISO/TR 52016-4:2024)
Energy performance of buildings - Energy needs for heating and cooling, internal
temperatures and sensible and latent heat loads - Part 4: Explanation and justification of
ISO 52016-3 (ISO/TR 52016-4:2024)
Energetische Bewertung von Gebäuden - Energiebedarf für Heizung und Kühlung,
Innentemperaturen sowie fühlbare und latente Heizlasten - Teil 5: Berechnungsverfahren
- Erklärung und Begründung zu ISO 52016-3 (ISO/TR 52016-4:2024)
Performance énergétiques des bâtiments - Besoins d'énergie pour le chauffage et le
refroidissement, les températures intérieures et les chaleurs sensible et latente - Partie
4: Titre manque (ISO/TR 52016-4:2024)
Ta slovenski standard je istoveten z: CEN ISO/TR 52016-4:2024
ICS:
27.015 Energijska učinkovitost. Energy efficiency. Energy
Ohranjanje energije na conservation in general
splošno
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN ISO/TR 52016-4
TECHNICAL REPORT
RAPPORT TECHNIQUE
November 2024
TECHNISCHER REPORT
ICS 91.120.10
English Version
Energy performance of buildings - Energy needs for
heating and cooling, internal temperatures and sensible
and latent heat loads - Part 4: Explanation and justification
of ISO 52016-3 (ISO/TR 52016-4:2024)
Performance énergétique des bâtiments - Besoins Energetische Bewertung von Gebäuden -
d'énergie pour le chauffage et le refroidissement, les Energiebedarf für Heizung und Kühlung,
températures intérieures et les chaleurs sensible et Innentemperaturen sowie fühlbare und latente
latente - Partie 4: Explication et justification de l'ISO Heizlasten - Teil 5: Berechnungsverfahren - Erklärung
52016-3 (ISO/TR 52016-4:2024) und Begründung zu ISO 52016-3 (ISO/TR 52016-
4:2024)
This Technical Report was approved by CEN on 4 October 2024. It has been drawn up by the Technical Committee CEN/TC 89.

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.
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COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TR 52016-4:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (CEN ISO/TR 52016-4:2024) has been prepared by Technical Committee ISO/TC 163
"Thermal performance and energy use in the built environment" in collaboration with Technical
Committee CEN/TC 89 “Thermal performance of buildings and building components” the secretariat of
which is held by SIS.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
Endorsement notice
The text of ISO/TR 52016-4:2024 has been approved by CEN as CEN ISO/TR 52016-4:2024 without any
modification.
Technical
Report
ISO/TR 52016-4
First edition
Energy performance of buildings —
2024-10
Energy needs for heating and
cooling, internal temperatures and
sensible and latent heat loads —
Part 4:
Explanation and justification of
ISO 52016-3
Performance énergétique des bâtiments — Besoins d'énergie
pour le chauffage et le refroidissement, les températures
intérieures et les chaleurs sensible et latente —
Partie 4: Explication et justification de l'ISO 52016-3
Reference number
ISO/TR 52016-4:2024(en) © ISO 2024

ISO/TR 52016-4:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO/TR 52016-4:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, subscripts and abbreviations . . 1
4.1 Symbols .1
4.2 Subscripts . .2
4.3 Abbreviated terms .2
5 Description of the method . 2
5.1 Output of the method . .2
5.2 General description of the method .2
5.2.1 General .2
5.2.2 Distinction between ISO 52016-3 and ISO 52016-1 .3
5.2.3 Successive steps in the calculation procedures .3
5.3 Technologies covered in ISO 52016-3 .3
5.3.1 General .3
5.3.2 Building envelope elements with dynamic solar shading .3
5.3.3 Building envelope elements with chromogenic glazing .6
5.3.4 Building envelope elements with an actively ventilated cavity .6
5.3.5 Types of adaptive building envelope elements not covered in ISO 52016-3 .9
5.4 Control scenarios .10
6 Calculation method .11
6.1 Output data .11
6.2 Calculation time intervals .11
6.3 Input data . 12
6.3.1 General . 12
6.3.2 Input data of a simplified adaptive building envelope element . 12
6.3.3 Input data of a detailed adaptive building envelope element . 12
6.3.4 Control related input data . 12
6.3.5 Climatic input data . 13
6.3.6 Constants and physical data . 13
6.3.7 Input data from Annex A and Annex B . 13
6.4 Properties of the adaptive building envelope element . 13
6.4.1 General . 13
6.4.2 Simplified or detailed adaptive building envelope element . 15
6.4.3 Properties of a simplified adaptive building envelope element . 15
6.4.4 Model and properties of a detailed adaptive building envelope element .16
6.5 Connection of the model of the adaptive building envelope element to the model of the
thermal zone of ISO 52016-1 .17
6.6 Selection of control type .17
6.7 Modelling of the control of the environmentally activated adaptive building envelope
element .17
6.8 Modelling of the control scenario for the actively controlled adaptive building envelope
element .18
6.8.1 General .18
6.8.2 Selection of conditions and events .18
6.8.3 Selection of sensors.19
6.8.4 Selection of methods to identify the conditions or events .19
6.8.5 Basic rules for the reference control scenario .21
6.8.6 Modelling of the user behaviour . 22
6.8.7 Reference control scenarios . 22
6.9 Hourly calculation procedures . 25

iii
ISO/TR 52016-4:2024(en)
6.10 Post-processing —Performance characteristics . 25
6.10.1 General . 25
6.10.2 Thermal comfort score . 25
6.10.3 Statistics on the use of the different states of the adaptive building envelope
element . 26
7 Quality control .26
8 Conformity check .26
9 Worked out examples .27
9.1 General .27
9.2 Purpose .27
9.3 Spreadsheet tool .27
9.4 Calculation cases .27
9.4.1 General .27
9.4.2 Building types . 28
9.4.3 Climates . 29
9.4.4 Operation and use profile . 29
9.4.5 Selected adaptive building envelope elements . 30
9.4.6 Control of adaptive building envelope elements . 30
9.5 Overview of selected cases and variants . 30
9.6 Results . .31
9.7 Conclusions . 39
9.7.1 General . 39
9.7.2 Limitations of the spreadsheet tool and example cases . 39
10 Validation of the calculation procedures.40
Annex A (informative) ISO 52016-3 input and method selection data sheet — Template . 41
Annex B (informative) ISO 52016-3 input and method selection data sheet — Default choices .42
Annex C (informative) Reference control scenarios for adaptive building envelope elements
with dynamic solar shading or chromogenic glazing .43
Annex D (informative) Basic study reference control strategies . 74
Annex E (informative) Hourly thermal balance model of ISO 52016-1 and the connected
adaptive building envelope element .82
Bibliography .92

iv
ISO/TR 52016-4:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by ISO Technical Committee ISO/TC 163, Thermal performance and energy
use in the built environment, Subcommittee SC 2, Calculation methods in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 89, Thermal performance of buildings
and building components, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
A list of all the parts in the ISO 52016 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
ISO/TR 52016-4:2024(en)
Introduction
0.1 Set of EPB standards and supporting tools
This document gives guidance to a set of international standards that is used to collectively assess the overall
energy performance of buildings (EPB). Throughout this document, this group of standards is referred to as
the “set of EPB standards”.
All EPB standards follow specific rules to ensure overall consistency, unambiguity and transparency (see
ISO 52000-1 , CEN/TS 16628 and CEN/TS 16629).
All EPB standards provide a certain flexibility with regard to the methods, the required input data and
references to other EPB standards, by the introduction of a normative template in Annex A and Annex B with
informative default choices.
One of the main purposes of the set of EPB standards is to enable laws and regulations to directly refer to
the EPB standards and make compliance with them compulsory. This requires that the set of EPB standards
consists of a systematic, clear, comprehensive and unambiguous set of energy performance procedures. The
number of options provided is kept as low as possible, taking into account national and regional differences
in climate, culture and building tradition, policy and legal frameworks (subsidiarity principle). For each
option, an informative default option is provided (see Annex B).
0.2 Rationale behind the set of EPB technical reports
There is a risk that the purpose and limitations of the EPB standards will be misunderstood, unless the
background and context to their contents, and the thinking behind them, is explained in some detail to
readers of the standards. Consequently, various types of informative contents are recorded and made
available for users to properly understand, apply and nationally or regionally implement the set of EPB
standards.
If this explanation were attempted in the standards themselves, the result is likely to be confusing, especially
if the standards are implemented or referenced in national or regional building codes.
Therefore, each EPB standard is accompanied by an informative technical report, e.g. this document, where
all informative content is collected, to ensure a clear separation between normative and informative content
(see CEN/TS 16629 for a more detailed explanation):
— to underscore the difference between the normative and informative content;
— to reduce the page count of the actual standard;
— to facilitate understanding of the set of EPB standards.
0.3 This document
This document gives guidance on ISO 52016-3. The role and the positioning of ISO 52016-3 in the set of EPB
standards is defined in the introduction of ISO 52016-3. A brief article on the subject can be found in the
[21]
REHVA Journal .
To fully understand this document, it is intended to be read in close conjunction, clause by clause, with
ISO 52016-3. Essential information provided in ISO 52016-3 is not repeated in this document. References to
a clause can refer to the combined content of that clause in both ISO 52016-3 and this document.
0.4 Accompanying spreadsheet
[35]
An extensive spreadsheet has been prepared to test and demonstrate ISO 52016-1. For the purpose of
testing and demonstrating ISO 52016-3, this spreadsheet has been extended with an (optional) sheet to
cover adaptive building envelope elements with different states and different control scenarios according to
ISO 52016-3.
Examples of calculations with adaptive building envelope elements are found in this document.

vi
ISO/TR 52016-4:2024(en)
0.5 Background of this document and ISO 52016-3
ISO 52016-3 and the supporting technical report (this document) have been developed to respond to a
strong need to include adaptive building envelope elements in the assessment of the energy performance of
buildings. This inclusion aims to create a level playing field for conventional and promising techniques.
More extensive background information and history of the whole set of EPB standards is given in the
introduction to ISO/TR 52000-2, the technical report accompanying the overarching EPB standard. Up-to-
date information on the set of EPB standards can be found in the "public material" section of the ISO/TC 163
1)
page on the ISO website.
0.6 Application area of ISO 52016-3
ISO 52016-3 specifies procedures for the calculation of the energy needs for heating and cooling, internal
temperatures and sensible and latent heat loads of a building according to ISO 52016-1, with additions or
modifications that are needed to incorporate adaptive building envelope elements in the calculation.
The main use of ISO 52016-3 is the assessment of the energy performance of buildings (energy performance
labels and certificates), including comparison between buildings and for checking compliance with minimum
energy performance criteria.
ISO 52016-3 is applicable to buildings at the design stage, to new buildings after construction and to existing
buildings in the use phase.
1) https://www.iso.org/committee/53476.html.

vii
Technical Report ISO/TR 52016-4:2024(en)
Energy performance of buildings — Energy needs for heating
and cooling, internal temperatures and sensible and latent
heat loads —
Part 4:
Explanation and justification of ISO 52016-3
1 Scope
This document provides explanation and justification to support the correct understanding and use of
ISO 52016-3.
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 7345, Thermal performance of buildings and building components — Physical quantities and definitions
ISO 9488, Solar energy — Vocabulary
ISO 52000-1, Energy performance of buildings — Overarching EPB assessment — Part 1: General framework
and procedures
ISO 52016-1, Energy performance of buildings — Energy needs for heating and cooling, internal temperatures
and sensible and latent heat loads — Part 1: Calculation procedures
ISO 52016-3:2023, Energy performance of buildings — Energy needs for heating and cooling, internal
temperatures and sensible and latent heat loads — Part 3: Calculation procedures regarding adaptive building
envelope elements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345, ISO 9488, ISO 52000-1,
ISO 52016-1 and ISO 52016-3:2023 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/
4 Symbols, subscripts and abbreviations
4.1 Symbols
For the purposes of this document, the symbols given in ISO 52000-1, ISO 52016-1 and ISO 52016-3:2023 apply.
More information on key EPB symbols is given in ISO/TR 52000-2.

ISO/TR 52016-4:2024(en)
4.2 Subscripts
For the purposes of this document, the subscripts given in ISO 52000-1, ISO 52016-1 and ISO 52016-3:2023 apply.
More information on key EPB subscripts is given in ISO/TR 52000-2.
NOTE 1 ISO 52016-1 uses input data from many technology fields. In the exceptional cases that subscripts in
ISO 52016-1 are different from subscripts in other EPB standards that produce output needed as input to ISO 52016-1,
these differences are reported in a special column in the tables with the overview of input data in 6.3. This can
occur when the source documents use subscripts that are crucial for that specific technology field, but conflict with
subscripts that are crucial for another specific technology field.
EXAMPLE Subscript g used for both "glazing" and for "ground".
NOTE 2 In ISO 52016-3 the subscript w (origin: “window”), used in ISO 52016-1 for transparent construction
elements is also used for the adaptive building envelope element.
NOTE 3 For the solar and daylight properties the subscript gl (origin: “glazing”), is used as a rule to specifically
refer to the projected area of the transparent part of the element.
4.3 Abbreviated terms
For the purposes of this document, the abbreviated terms given in ISO 52016-1 and ISO 52016-3:2023 apply.
More information on key EPB abbreviated terms is given in ISO/TR 52000-2.
5 Description of the method
5.1 Output of the method
The structure of ISO 52016-3:2023, Clause 5 conforms to the common template for the set of EPB standards.
ISO 52016-3:2023, Clause 5 contains a brief (qualitative) description of the method, starting with the main
output from the standard.
ISO 52016-3 covers the calculation of the energy need for heating and cooling and the internal temperature
in case of a building or building zone with one or more adaptive building envelope elements.
The method covers also, as product information, the calculation of some energy performance characteristics
of adaptive building envelope elements, applied in a specific (e.g. reference) building.
NOTE Compare e.g. ISO 18292, that also uses a reference building for comparing the energy performance of
windows.
This includes information on whether the building is smart ready in terms of adaptive building envelope
elements.
5.2 General description of the method
5.2.1 General
The calculation procedures in ISO 52016-3 are an extension of the hourly calculation procedures specified in
ISO 52016-1. ISO 52016-3 contains the additions and modifications that are needed to incorporate adaptive
building envelope elements. Therefore, ISO 52016-1 is referenced accordingly throughout ISO 52016-3.
ISO 52016-1:2017 contains a normative Annex G that provides a framework for calculation procedures
involving adaptive building envelope elements. ISO 52016-3 provides calculation procedures.
ISO 52016-3 fills a gap in the set of EPB standards.
The reasons for choosing an hourly calculation time interval are given in 6.2.

ISO/TR 52016-4:2024(en)
5.2.2 Distinction between ISO 52016-3 and ISO 52016-1
The calculation procedures of ISO 52016-3 can be seen as an extension of the procedures given in ISO 52016-1.
The reasons for providing these in two separate documents are:
— If ISO 52016-3 was combined into ISO 52016-1, it can harm the acceptance and roll-out of ISO 52016-1,
e.g. if a legal authority wants to adopt the calculation procedures of the current ISO 52016-1, but has
hesitations to adopt ISO 52016-3.
— Maintenance of ISO 52016-1 would be more difficult and costly if combined with the content of
ISO 52016-3. With a separate ISO 52016-3 it is easier to plan revisions, e.g. based on experiences by users
or developing technologies.
— ISO 52016-3 requires specific expertise on the technologies and control scenarios involved.
— The parties interested in the details of ISO 52016-3 are quite specific. Combining all in one document
would not be efficient from the user perspective.
5.2.3 Successive steps in the calculation procedures
In ISO 52016-3:2023, the actual calculation procedures are given in 6.9. However, that subclause is just one
sentence:
"Apply the hourly calculation procedures according to ISO 52016-1:2017, 6.5, with the additions and
adaptations specified in the previous clauses of this document."
ISO 52016-3:2023, 6.4 to 6.8 contain the procedures needed to prepare the calculation. In ISO 52016-3:2023,
5.4, these preparatory steps are introduced as six successive steps.
5.3 Technologies covered in ISO 52016-3
5.3.1 General
The technologies covered in ISO 52016-3 are selected on the basis of current or promising market share
and distinction in functionality and control scenarios or passive response. Some technologies can be quite
different in appearance but very similar in functionality and in options for control. For the purpose of
ISO 52016-3 these are not categorized separately.
For example, for the purpose of ISO 52016-3 the physical model of a closed (unvented) cavity double skin
façade is quite similar to a multiple glazing unit with integrated solar blinds.
Three main categories of technologies are covered in ISO 52016-3:
— Building envelope elements with dynamic solar shading (see 5.3.2).
— Building envelope elements with chromogenic glazing (see 5.3.3).
— Building envelope elements with an actively ventilated cavity (see 5.3.4).
For the sources used in the selection of technologies, see References 35, 28, 17, 18, 27, 34 and 38.
Examples of types of adaptive building envelope elements that are not covered in ISO 52016-3 are presented
in 5.3.5.
5.3.2 Building envelope elements with dynamic solar shading
A building envelope element with dynamic solar shading can be described as a façade element (usually fitted
to a window, door, curtain walling or façade, with one or more actively operated mobile parts) defined as
the curtain that can (partially) obstruct solar radiation or sunlight. The aim of dynamic solar shading is
to control solar radiation and daylight, to contribute to the thermal insulation, thermal comfort, cooling
savings and visual comfort when combined to glazing.

ISO/TR 52016-4:2024(en)
Dynamic solar shading can be positioned at the internal or external side of the façade element or integrated
in between two or more façade elements. These façade elements may form a sealed multiple glazing unit, or
consist of an assembly of multiple glazings, or assembly of partly transparent and partly opaque elements.
If a single façade is doubled inside or outside by a second, essentially glazed façade, it is usually defined as a
double skin façade. The width of the cavity between these two skins can range from several centimetres at
the narrowest to several metres for the widest accessible cavities. As long as such a façade has no intentional
ventilation provisions (“closed cavity façade”) it fits into the description of the dynamic solar shading.
This contrasts with the third category, building envelope elements with an actively ventilated cavity.
The main technologies for the dynamic solar shading elements are:
— Venetian blind: blind where the curtain consists of horizontal slats which can be tilted and where the
curtain may be retracted by accumulating the slats. The slat angle can be tilted in various positions. They
are usually opaque, but can also be partly transparent or translucent.
— Roller blind: blind where the curtain consists of material (e.g. fabric) which is retracted by rolling.
The curtain can be semi-transparent, semi-translucent or opaque, and sometimes thermally insulated
(multilayer).
— Roller shutter: shutter where the curtain is retracted by rolling and consists of interconnected horizontal
laths, that can be tilted or not, which run inside channels.
Examples are shown in Figure 1:

ISO/TR 52016-4:2024(en)
a) Windows with internal roller blinds b) Windows with external venetian blinds.
2)
(Colour) photo by Samuel Zeller, CC0 1.0 DEED
c) Closed cavity façade with integrated venetian d) External folding-sliding shutters, Gerrit Rietveld
blinds Academie / Sandberg Instituut, Amsterdam
Figure 1 — Four examples of building envelope elements with dynamic solar shading
For movable blinds or shutters, a specific terminology is used to avoid confusion between the blind or
shutter movement and other movements, such as slats and louvers:
— Extended/retracted: movement of the blind resulting in an increase/decrease in the surface area covered
(see EN 12216:2018, 5.1)
2) No permission required. Credit: https:// creativecommons .org/ publicdomain/ zero/ 1 .0/

ISO/TR 52016-4:2024(en)
— Open/closed: terms used to describe the increase in light (opening) or reduction of light (closing) in
an extended position for products with laths, slats or louvres which can be tilted or adjusted (see EN
12216:2018, 5.1).
See also examples in EN 12216.
5.3.3 Building envelope elements with chromogenic glazing
Chromogenic glazing can be described as an adaptive technology directly integrated in the glazing itself.
The physical properties can reversibly change according to a specific active or passive trigger, changing
the appearance of the glazing itself: making it more or less transparent, absorbing or reflecting for solar
radiation and daylight.
The main technologies currently available on the market are:
— Thermochromic and thermotropic glazing (passive; based on the glazing temperature changing);
— Photochromic glazing (passive; based on the level of incident solar irradiance changing);
— Electrochromic glazing (active; based on the level of electric power changing);
— Gasochromic glazing (active, based on changing gas mixture in cavity);
— Liquid crystal chromogenic glazing (active; based on the level of electric power changing);
— Suspended particle devices.
However, other smart glazing technologies are being, or may be developed, that can be simulated in the
same way, e.g. electrophoretic, fluidic glass, microshades and micromirror arrays.
Examples are shown in Figure 2:
a) High transmittance b) Low transmittance
Key
SOURCE: Project Hamilton Bonaduz, Switzerland. Electrochromic Glass (SageGlass). Pictures by Ingo Rasp.
Figure 2 — Examples of building envelope with chromogenic glazing
5.3.4 Building envelope elements with an actively ventilated cavity
5.3.4.1 Distinctive feature
A building envelope element with an actively ventilated cavity is similar to a building envelope element with
dynamic solar shading, except for the intentional and possibly controlled (i.e. natural, hybrid or mechanical)
ventilation of the cavity or air circulation via the cavity.

ISO/TR 52016-4:2024(en)
In many cases it is a ventilated double skin façade, but also a ventilated window with the intention to capture
heat from the cavity fits into this category.
In addition to achieving thermal and solar control as in the previous two categories, the technologies under
this category have in common that air is deliberately circulated through the cavity, to gain solar either heat,
increase thermal comfort, or both, when heating is required and to enhance thermal comfort and reject
surplus solar load during warm periods. If this is not the case, then, for the purpose of this document, the
adaptive building envelope element does not belong to this category.
The difference with operable solar shading in 5.3.2 is that the air circulation and ventilation is controlled,
either mechanically or by operable vents, thus adding a dimension to the control strategy.
5.3.4.2 Variety of technologies
A wide variety of technologies exist. Typical examples are:
— Double skin façade
— with integrated solar shading;
— mechanically or naturally ventilated;
— with fixed or adjustable vent openings;
— with narrow or wide cavity.
— Ventilated windows
— with integrated blinds;
— to either harvest or reject solar heat, recover heat from ventilation air, or both.
See more examples below in this subclause such as a simplified façade with air extracted behind an internal
screen instead of glazing.
Active ventilative co
...