prEN ISO 16484-3

SLOVENSKI STANDARD
01-september-2026
Sistemi za avtomatizacijo in regulacijo stavb (BACS) - 3. del: Funkcije (ISO/DIS
16484-3:2026)
Building automation and control systems (BACS) - Part 3: Functions (ISO/DIS 16484-
3:2026)
Systeme der Gebäudeautomation (GA) - Teil 3: Funktionen (ISO/DIS 16484-3:2026)
Systèmes de gestion technique du bâtiment (SGTB) - Partie 3: Fonctions (ISO/DIS
16484-3:2026)
Ta slovenski standard je istoveten z: prEN ISO 16484-3
ICS:
35.240.67 Uporabniške rešitve IT v IT applications in building
gradbeništvu and construction industry
97.120 Avtomatske krmilne naprave Automatic controls for
za dom household use
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 16484-3
ISO/TC 205
Building automation and control
Secretariat: ANSI
systems (BACS) —
Voting begins on:
Part 3: 2026-06-25
Functions
Voting terminates on:
2026-09-17
Systèmes de gestion technique du bâtiment (SGTB) —
Partie 3: Fonctions
ICS: 91.040.01; 35.240.67
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
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This document is circulated as received from the committee secretariat.
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Reference number
ISO/DIS 16484-3:2026(en)
DRAFT
ISO/DIS 16484-3:2026(en)
International
Standard
ISO/DIS 16484-3
ISO/TC 205
Building automation and control
Secretariat: ANSI
systems (BACS) —
Voting begins on:
Part 3:
Functions
Voting terminates on:
Systèmes de gestion technique du bâtiment (SGTB) —
Partie 3: Fonctions
ICS: 91.040.01; 35.240.67
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
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TO SUBMIT, WITH THEIR COMMENTS,
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NOTIFICATION OF ANY RELEVANT PATENT
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 16484-3:2026(en)
ii
ISO/DIS 16484-3:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, abbreviations and acronyms . 2
5 Functions . 3
5.1 Introduction .3
5.2 BAC functions .3
5.3 TBM functions .3
5.4 User operation functions .4
5.4.1 Overview .4
5.4.2 Types of interaction .4
5.4.3 User operation functions .4
6 Functional specification of requirements . 8
6.1 Overview .8
6.1.1 Structure of the requirements .8
6.1.2 Description of functions .10
6.1.3 Description of function block examples .10
6.1.4 Description of the BACS function list .11
6.2 General system criteria .11
6.3 Software . 12
6.3.1 BACS programs general . . 12
6.3.2 System management programs . 12
6.3.3 Communication programs .16
6.3.4 BACS application programs .18
6.3.5 Human system interface programs .19
6.3.6 Service and commissioning functions . 25
6.3.7 Operating system . 26
6.4 System engineering programs .27
6.4.1 General description of the engineering process .27
6.4.2 Project specific system design .27
6.4.3 Hardware configuration .27
6.4.4 Control strategy configuration . 28
6.4.5 Management and operator functions configuration . 28
6.4.6 Commissioning tool . 29
6.5 BACS function types . 30
6.5.1 General requirements for BACS functions. 30
6.5.2 I/O function types . 30
6.5.3 Processing function types . 33
6.5.4 Management function types .62
6.5.5 Operator function types . 65
Annex A (informative) BACS function list (BACS FL) . 67
Annex B (informative) Examples for control schematics and BACS function lists .71
Bibliography .83

iii
ISO/DIS 16484-3:2026(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16484-3 was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 247, Building automation, controls and building management, in collaboration with Technical
Committee ISO/TC 205, Building environment design, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement)
This second edition cancels and replaces the first edition (ISO 16484-3:2005), which has been technically
revised.
The main changes are as follows:
— overall structure of document has been updated;
— Clause 3, Clause 5 and Clause 6 have been revised;
— technical content throughout the document has been modified and updated.
A list of all parts in the ISO 16484 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.

iv
ISO/DIS 16484-3:2026(en)
Introduction
This series of standards is intended for design of new buildings and retrofit of existing buildings for an
acceptable indoor environment, practical energy conservation, and efficiency.
The application of this series of standards for BACS is envisaged as follows:
— the environmental design for all building types requires complex methods for automation and control.
The functional integration of services other than HVAC is a general task for all parties employed to
develop an integrated multi-application system. The Integration comprises, e.g. lighting and electric
power distribution control, security control, transportation, maintenance management, or facilities
management. This system integration allows the user to take advantage of synergies between the
different applications. This standard will give guidance to architects, consultants, and contractors as
well as to users on how to share such resources;
— the innovation cycles between devices, systems, and networks vary. To make it possible to add and to
change existing devices, and extend the building automation and control network, several interfaces
both proprietary and standardized are defined between the BACS network and the other systems. A
manufacturer can design a product, both to meet his specific marketing objectives and to give the option
to integrate that special device into a multi-application BACS. Interfaces are also defined in appropriate
parts of this standard along with the necessary communications protocol and conformance test required
to support the inter-working of devices;
— a manufacturer, a systems house, or an electrical or mechanical contractor can assemble an implementation
of a building automation and control system;
— the application of this standard is not to standardize the hardware and software design or the architecture
of a System, but to define the process for the creation of project specifications, where functionality and
the quality of the solution are clearly defined.
The purpose of this series of standards is intended for use by those involved in the design, manufacture,
engineering, installation, commissioning, operational maintenance and training of BACS when contracted,
i.e.:
— as a guide to the terminology of the building automation and control trade. Unambiguous terminology is
required for a complete and accurate conveyance of the intent and details of this standard;
— in product development, to avoid unnecessary duplication of function or terminology, but should not
place a restraint on the evolution of new products, systems or applications;
— as a basis for interfacing products and systems. In order to interoperate, the elements of a BACS require
a unified data communication protocol and information model;
— as a basis for drawing up a project specification for the procurement of building automation and control
products for systems suppliers and customers;
— as a code of practice for expertly commissioning prior to handover of a system;
— by educational establishments wishing to train people in the field of building automation and control
systems.
This entire series of BACS standards consists of the following contents:
Part 1: Overview and definitions
Part 1 of this standard describes the objectives and interrelationships of all parts of this standard. It
provides an overview and detailed information about the structure of the related series of standards for the
BACS industry.
This part of the standard provides also the vocabulary with terms and definitions for the understanding of
the entire series of this standard and it contains a translation of the main terms in English, French, Russian,
and German in an informative annex.

v
ISO/DIS 16484-3:2026(en)
Part 2: Hardware
Part 2 of this standard specifies the requirements for the hardware to perform the tasks within a BACS. It
provides the terms, definitions, and abbreviations for the understanding of Part 2 and Part 3.
Part 2 relates only to physical items/devices, i.e.:
— devices that require human interaction, such as management stations or operator panels;
— devices for data storage and analysis, such as edge or cloud servers;
— devices for control applications, such as automation stations;
— devices for physical quantities acquisition, such as sensors and actuators.
— Part 2 provides a generic system topology based on a building network infrastructure, which includes
both the devices inside the building envelope and those outside the building envelope.
National annexes:
National annexes may specify the local requirements of physical and electrical characteristics, the
verifications for BACS devices and equipment, and the code of practice for the physical installation of
systems. The annexes shall refer to the regional implementations of the relevant IEC standards.
Part 3: Functions (refer to the scope of this part)
Part 4: Applications
Part 4 of this standard specifies the requirements for specific communicating applications/devices, e.g. for
general room automation and for sophisticated optimization of controls for heating, fan coil and induction
units, CAV, VAV and radiant cooling.
It specifies control applications and function blocks focusing on, but not limited to, lighting, solar protection
and heating, ventilation and air conditioning (HVAC) applications.
It describes how energy performance, comfort, and operational requirements of buildings as defined by EN
ISO 52120-1, Table 5, are translated into functional specifications for integrated plant and room control.
Part 5: Data Communication – Protocol
Part 5 of this standard specifies data communication services and objects for computer equipment and
controllers used for monitoring and control of HVAC&R and other systems of building services.
This protocol provides a comprehensive set of object types for conveying encoded binary, analog, and
alphanumeric data between devices including, but not limited to:
— input measuring: analog input object;
— output positioning/setpoint: analog output object;
— binary input counting;
— input state: binary input object, multi-state input;
— output switching: binary output object, multi-state output;
— values: analog value, binary value, multi-state value, accumulated value, averaging object, trend log
object;
— text string;
— schedule information;
— alarm and event information;

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ISO/DIS 16484-3:2026(en)
— files; and
— control programs and parameters respectively.
This protocol models each building automation and control system as a collection of data structures called
object types, the properties of which represent various aspects of the hardware, software, and operation
of the device. These objects provide a means of identifying and accessing information without requiring
knowledge of the details of the device's internal design or configuration.
NOTE An overview of possible integration with other systems in buildings, e.g. fire, security, access control,
maintenance and facilities management, is shown in Figure 1 of Part 2 of this standard.
Part 6: Data communication conformance testing
Part 6 of this standard specifies the technical requirements of the conformance test suite and the methods
for testing the products for the conformance with the protocol. It provides a comprehensive set of
procedures for verifying the correct implementation of each capability claimed on a BACS network protocol
implementation conformance statement (PICS) including:
— support of each claimed BACS network service, either as a client (initiator), server (executor), or both;
— support of each claimed BACS network object-type, including both required properties and each claimed
optional property;
— support of the BACS network layer protocol;
— support of each claimed data link option, and
— support of all claimed special functionality.

vii
DRAFT International Standard ISO/DIS 16484-3:2026(en)
Building automation and control systems (BACS) —
Part 3:
Functions
1 Scope
This Part 3 of the standard specifies in clause 5 the functions for control, building automation and technical
building management which contribute to the energy performance of buildings as listed in EN ISO 52120-1,
table 5.
This part of the standard further provides in clause 6 means for functional specification of requirements
for the overall functionality and engineering services to achieve building automation and control systems. It
defines terms, which shall be used for specifications and it gives guidelines for the functional documentation
of project/application specific systems. It provides a sample template for documentation of plant/application
specific functions, called BACS points list in informative annex A.
The informative function block examples explain a method to display the referenced functions in system
documentation; they do not standardize the method for programming functions and applications.
2 Normative references
The following referenced documents are indispensable for the application of this International Standard. For
dated references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 10628, Flow diagrams for process plants — General rules
ISO 16484-2, Building automation and control systems (BACS) — Part 2: Hardware
ISO 16484-4, Building automation and control systems (BACS) — Part 4: Control Applications
ISO 16484-5, Building automation and control systems (BACS) — Part 5: Data communication protocol
ISO 52120-1:2021, Energy performance of buildings — Contribution of building automation, controls and
building management — Part 1: General framework and procedures
ISO 52127-1:2021, Energy performance of buildings — Building management system — Part 1: Module M10-12
1)
IEC 60617-12:1998 , Graphical symbols for diagrams — Part 12: Binary logic elements
1)
IEC 60617-13:1993 , Graphical symbols for diagrams — Part 13: Analogue elements
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 16484-2 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/
1) Withdrawn. Replaced by IEC 60617:2001.

ISO/DIS 16484-3:2026(en)
3.1
building automation and control
BAC
products, software, and engineering services for automatic controls, monitoring and optimization, human
intervention and management to achieve energy-efficient, economical, and safe operation of building
services equipment
[SOURCE: ISO 52120 1:2021, 3.2]
3.2
technical building management
TBM
process(es) and services related to operation and management of buildings and technical building system
(3.14) through the interrelationships between the different disciplines and trades
Note 1 to entry: The disciplines and trades comprise all technical building services for the purpose of optimized
maintenance and energy consumption.
EXAMPLE Optimization of buildings through interrelationships ranging from heating, ventilation and air
conditioning (HVAC), to lighting and day lighting, to life safety and security, to electric power systems and energy
monitoring and metering, to services, including communications and maintenance and to management.
[SOURCE: ISO 52127 1:2021, 3.2]
4 Symbols, abbreviations and acronyms
For the purposes of this standard, the symbols, abbreviations and acronyms given in ISO 16484-2 apply.
Abbreviated terms:
Abbreviated Description
term
AHU air handling unit
AI analogue input
AO analogue output
BACS building automaton control system
BACS FL BACS function list
BI binary input
BO binary output
CI counter input
DIU data interface unit
EMC electromagnetic compatibility
GUI graphical user interface
HMI human-machine interface
I/O input/output
LAN local area network
LO/ID Local object identifier
MOU memorandum of understanding
PABS packaged air-cooled brine chiller
PI proportional-integral
PID proportional-integral-differential
TBM technical building management
NOTE The abbreviations used and explained within the tables for the function block examples are for information
only.
ISO/DIS 16484-3:2026(en)
5 Functions
5.1 Introduction
The purpose of a space or room in a building determines the required level of temperature, humidity, air
exchange rate or other conditional state of the space. Wiring, piping, ducting and other infrastructure
elements provide the electrical, heating and cooling energy and air for control of the desired space conditions.
The purpose of the building automation and control system (BACS) is to provide the desired space conditions
with the least possible energy usage.
The purpose of technical home and building management (TBM) is to adapt the control settings to the
actual usage of a building plant, space or room. The control settings also support improving the energy
performance of a building by managing energy use systematically.
The contribution of building automation and control as well as technical building management functions
towards the energy performance of buildings is listed in EN ISO 52120-1, table 5.
The different levels of functional characteristics of BAC and TBM functions are assigned to BAC efficiency
classes, from D (lowest level) to A (highest level) in EN ISO 52120-1, table 6.
5.2 BAC functions
BAC functions include heating control, domestic hot water supply control, cooling control, ventilation and
air-conditioning control, lighting control and blind control for indoor environmental quality (thermal and
lighting) in a space or room.
ISO 16484-4, clause 5, provides functional specifications having an impact on energy performance, comfort,
and operational requirements of buildings. These specifications provide a description and target for each
BAC function listed in ISO 52120-1, table 5. Mandatory and optional inputs as well as mandatory and optional
outputs are also provided.
5.3 TBM functions
The technical home and building management (TBM) enables to adapt easily the operation to the user needs.
This is achieved by applying the following recommendations.
Check at regular intervals that
— the operation schedules of heating, cooling, ventilation and lighting is well adapted to the actual used
schedules and that the setpoints are also adapted to the needs.
— attention is paid to the tuning of all controllers, this includes setpoints as well as control parameters
such as PI controller coefficients.
— heating and cooling setpoints of the room controllers are checked at regular intervals. The users often
modify these setpoints. A centralized system enables to detect and correct extreme values of setpoints
due to misunderstanding of users.
— if interlock between heating and cooling control of emission and/or distribution is only a partial interlock,
the setpoint shall be regularly modified to minimize the simultaneous use of heating and cooling.
— alarming and monitoring functions support the adaptation of the operation to user needs and the
optimization of the tuning of the different controllers. This will be achieved by providing easy tools to
detect abnormal operation (alarming functions) and by providing easy way to log and plot information
(monitoring functions).
— the interaction with the electrical and thermal energy system as well as the interaction with the electrical
vehicle system supports flexible building operation.

ISO/DIS 16484-3:2026(en)
5.4 User operation functions
5.4.1 Overview
Users interfacing with BACS and TBM have different perspectives (e.g. as room occupant, maintenance
personnel, building operator) and different types of interaction requiring visual (vision), auditory (hearing),
or tactile (touching) capabilities.
Different types of interaction are described in 5.4.2.
The perspectives may be related to a space (e.g. room, floor, building), a plant (e.g. chiller, boiler, solar PV),
an operating mode (e.g. occupied – unoccupied, on - off), or physical values (e.g. temperature, flow, volume,
energy usage rate). These different perspectives have an influence on the user interfaces that need to be
provided and specified.
User operation functions for BACS and TBM functions listed in EN ISO 52120-1, table 5, are described for
selected perspectives in 5.4.3.
5.4.2 Types of interaction
The level of interaction of users with BACS and TBM depends on their perspective.
The interaction of users with BACS and TBM may be based on visual, auditory, or tactile interfaces. Room
occupants may have impairments (e.g. red-green blindness) that have an impact on the usability of user
interfaces. Depending on the purpose of the building and the expected capabilities of the typical room
occupant the user interfaces should be designed to enable control by users with impairments.
Depending on the perspective the user interface may be designed for an untrained person (e.g. room
occupant) or for trained personnel (e.g. maintenance personnel, building operator). The user interface for
room occupants enables them to manually change or override the room control functions (e.g. temperature
setpoint). Manual or automatic reset to preset settings is a functionality of a building operator or a
supervisory optimization function (e.g. energy management system).
5.4.3 User operation functions
5.4.3.1 Setpoint management
5.4.3.1.1 Perspective >building operator<
Referring to EN ISO 52120-1, table 5, point 7.1, a building operator may execute these functions:
— management, set back and adaptation of BAC setpoints according to the room/zone operating modes
— manual setting room by room individually
— adaptation from distributed/decentralized plant rooms only
— adaptation from a central room (e.g. work station, web operation; room operating units are excluded)
— adaptation from a central room (e.g. work station, web operation; room operating units are excluded)
with frequent set back of user inputs.
Referring to EN ISO 52120-1, table 5, point 7.1, a building operator may control the room temperature
setpoint not only in the room if at least one of the following modes are applied:
— heating emission control with individual (modulating) room control (1.1 – type 2, 3 or 4) is available
— cooling emission control with individual (modulating) room control (3.1 – type 2, 3 or 4) is available
— heating emission control for TABS (modulating) room control (1.2 – type 1, 2, or 3) is available

ISO/DIS 16484-3:2026(en)
— cooling emission control for TABS (modulating) room control (3.2 – type 1, 2, or 3) is available
— heating emission control with individual (modulating) room control (1.1 – type 2, 3 or 4) is available
— cooling emission control with individual (modulating) room control (3.1 – type 2, 3 or 4) is available
— heating emission control for TABS (modulating) room control (1.2 – type 1, 2, or 3) is available
— cooling emission control for TABS (modulating) room control (3.2 – type 1, 2, or 3) is available.
5.4.3.1.2 Perspective >room occupant<
Referring to EN ISO 52120-1, table 5, a room occupant may control the indoor environment setpoints of
room temperature, humidity or CO level if at least one of the following modes are applied:
— heating emission control with individual (modulating) room control (1.1 – type 2, 3 or 4) is available
— cooling emission control with individual (modulating) room control (3.1 – type 2, 3 or 4) is available.
— humidity control (4.10 – type 1 or 2)
— ventilation control
5.4.3.2 Runtime management
5.4.3.2.1 Perspective >building operator<
Referring to EN ISO 52120-1, table 5, point 7.2, a building operator may adapt system/plant operating hours
according to given time schedule and/or calendar.
Refer to EN ISO 52127-1, clause 7, for details on how to apply runtime management.
5.4.3.3 Detecting faults of technical building systems and providing support to the diagnosis of
these faults
5.4.3.3.1 Perspective >building operator<
Referring to EN ISO 52120-1, table 5, point 7.3, a building operator may be supported in detecting faults of
technical building systems and provided with support to the diagnosis of these faults.
A building operator may have these levels of support:
— with central indication of detected faults and alarms (e.g. equipment or communication network)
— with central indication of detected faults and alarms including diagnosing functions (e.g. providing
support in identifying and addressing the root cause).
5.4.3.3.2 Perspective >maintenance mode<
If a part of the BACS is operated in maintenance mode then alarms are blocked unless these alarms are
lifesaving.
5.4.3.4 Reporting information regarding energy consumption and indoor conditions
5.4.3.4.1 Perspective >building operator<
Refering to EN ISO 52120-1, table 5, point 7.4, a building operator may receive reports information regarding
energy consumption, indoor conditions for different levels of analysis, performance evaluation and
benchmarking of indoor environment and energy usage.

ISO/DIS 16484-3:2026(en)
A building operator may have these levels of support:
— indication of actual values only
— trending functions and consumption determination
— analysing, performance evaluation, benchmarking of indoor environment and energy.
5.4.3.5 Local energy production and renewable energies
5.4.3.5.1 Perspective >building operator<
Referring to EN ISO 52120-1, table 5, point 7.5, a building operator may manage local renewable energy
sources (RES) and other local energy productions as CHP (combined heat and power). The intention is to
optimize the own usage of the RES and CHP.
Refer to EN ISO 52127-1, clause 9, for details on managing local renewable energy sources and other local
energy productions as CHP (combined heat and power).
5.4.3.6 Waste heat recovery and heat shifting
5.4.3.6.1 Perspective >building operator<
Referring to EN ISO 52120-1, table 5, point 7.6, a building operator may use waste heat recovery on the
building level and heat shifting using thermal energy storage to optimize energy performance of the building.
Refer to EN ISO 52127-1, clause 10, for details on waste heat recovery on the building level and heat shifting
using thermal energy storage to optimize energy performance of the building.
5.4.3.7 Smart grid integration
5.4.3.7.1 Perspective >building operator<
Referring to EN ISO 52120-1, table 5, point 7.7, a building operator may use interactions between building
and smart grid including demand side management to reduce cost and operate in support of grid stability.
Refer to EN ISO 52127-1, clause 11, for details on interactions between building and smart grid including
demand side management.
5.4.3.8 Heating control
5.4.3.8.1 Perspective >building operator<
EN ISO 52120-1, table 5, point 1, provides eleven different options for heat generation, storage, distribution
and emission. Combining these options covers different system designs.
EN ISO 52120-1, table 6, point 1 provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.8.2 Perspective >room occupant<
EN ISO 52120-1, table 5, point 1.1, provides individual control of the room temperature by the room occupant.
EN ISO 52120-1, table 6, point 1.1 provides the efficiency class that can be achieved when a specific option is
applied.
ISO/DIS 16484-3:2026(en)
5.4.3.9 Domestic hot water supply control
5.4.3.9.1 Perspective >building operator<
EN ISO 52120-1, table 5, point 2, provides four different options for control of domestic hot water supply.
EN ISO 52120-1, table 6, point 2 provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.10 Cooling control
5.4.3.10.1 Perspective >building operator<
EN ISO 52120-1, table 5, point 3, provides ten different options for cooling generation, storage, distribution
and emission. Combining these options covers different system designs.
EN ISO 52120-1, table 6, point 3 provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.10.2 Perspective >room occupant<
EN ISO 52120-1, table 5, point 3.1, provides individual control of the room temperature by the room occupant.
EN ISO 52120-1, table 6, point 3.1 provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.11 Ventilation and air-conditioning control
5.4.3.11.1 Perspective >building operator<
EN ISO 52120-1, table 5, point 4, provides ten different options for ventilation and air conditioning control.
EN ISO 52120-1, table 6, point 4 provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.11.2 Perspective >room occupant<
EN ISO 52120-1, table 5, point 4.1, provides individual control of ventilation in a room either based on time
control, occupancy or demand.
EN ISO 52120-1, table 6, point 4.1 provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.12 Lighting control
5.4.3.12.1 Perspective >building operator<
EN ISO 52120-1, table 5, point 5, provides occupancy and light level-based control of lighting in a room.
EN ISO 52120-1, table 6, point 5, provides the efficiency class that can be achieved when a specific option is
applied.
5.4.3.12.2 Perspective >room occupant<
EN ISO 52120-1, table 5, point 5, provides occupancy and light level-based control of lighting in a room.

ISO/DIS 16484-3:2026(en)
5.4.3.13 EN ISO 52120-1, table 6, point 5, provides the efficiency class that can be achieved when a
specific option is applied. Blind control
5.4.3.13.1 Perspective >building operator<
EN ISO 52120-1, table 5, point 6.1, provides motorized operation with manual or automatic control as well as
combined light/blind/HVAC control.
EN ISO 52120-1, table 6, point 6.1, provides the efficiency class that can be achieved when a specific option
is applied.
5.4.3.13.2 Perspective >room occupant<
EN ISO 52120-1, table 5, point 6.1, provides motorized operation with manual or automatic control as well as
combined light/blind/HVAC control.
EN ISO 52120-1, table 6, point 6.1 provides the efficiency class that can be achieved when a specific option is
applied.
6 Functional specification of requirements
6.1 Overview
6.1.1 Structure of the requirements
6.1.1.1 General
This standard does not dedicate the system functionality to any particular hardware. The functional
requirements in this part of the standard are subdivided as follows:
— project/plant specific functions:
describes the requirements for plant applications and/or project specific functions and methods for the
functional documentation of project and/or application specific systems;
— system application and management software:
describes the requirements for plant independent system programs and human system interface
programs related to a project in general;
— engineering and commissioning tools:
describes the requirements for the configuration of hardware, of control strategies and management
functions, and the commissioning process.
The functions of a BACS in general are structured into three levels. These levels indicate functions for:
— management,
— automation/control as processing functions, and
— input/output as interface to field devices.
Operator functions are not assigned to a specific level.
NOTE Requirements for the hardware and communication means to perform the BACS software and functions
that are specified in Part 2 of this standard.

ISO/DIS 16484-3:2026(en)
6.1.1.2 Operator functions
Human system interface for plant operation, i.e. for supervision, alarm annunciation, state monitoring and
human interaction are not assigned to any functional level.
The range of functionality covers:
a) system management, event management and state management, parameter adjustment and manual on/
off control;
b) local room operation;
c) local override/indication device functions to provide restricted access for service operation;
d) system engineering and servicing, engineered operator functions are, e.g. dynamic display, event
instruction text, remote messaging (see 5.5.5).
NOTE
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