ISO 6284:2023
(Main)Technical product documentation — Construction documentation — Indication of limit deviations
Technical product documentation — Construction documentation — Indication of limit deviations
This document specifies methods for the indication of limit deviations on construction documents.
Documentation technique de produits — Documentation de construction — Indication des écarts limites
Le présent document spécifie les méthodes à utiliser pour indiquer les écarts limites sur les documents de construction.
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 6284
Third edition
2023-05
Technical product documentation —
Construction documentation —
Indication of limit deviations
Documentation technique de produits — Documentation de
construction — Indication des écarts limites
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 2
4.1 Generality . 2
4.2 Application . 2
4.3 Designations of deviation types . 2
5 Indication of limit deviations .3
5.1 As dimensions on construction drawings or figures within notes . 3
5.2 As property items within data templates . 5
Bibliography .11
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 10, Technical product documentation,
Subcommittee SC 8, Construction documentation.
This third edition cancels and replaces the second edition (ISO 6284:1996), which has been technically
revised.
The main changes are as follows:
— validation of normative references;
— consideration of multiple categories of deviations;
— definitions of indications of limit deviations using building information modelling (BIM).
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
Introduction
Deviations are a common part of the built environment which are often left to operatives on site to
resolve. With the development of prefabrication, there is recognition that control of deviations is an
essential requirement to improve the quality of building and infrastructure works. It is important for
architectural designers, product manufacturers and constructors to indicate limit deviations and work
to these, where they exist.
The previous edition, ISO 6284:1996, pointed out some basic principles and ways to indicate limit
deviations. It focused on graphical presentations, generally drawings, as a method for delivering
construction and product information. Technically, limit deviations are about not only geometric
information but also the requirements, which shall be delivered objectively by parties to a project.
The digitization of construction requires both graphical and alphanumeric information to be presented
in a formal way to achieve both human-readability and machine-readability.
Data templates are a formal representation method adopted widely to describe exchange information
or product specifications for machine-readability. ISO 23387 has been developed to support digital
processes using formats which are machine-interpretable, based upon standardized data structures, to
exchange information about any type of construction object.
This document focuses on how to provide indication methods for limit deviations that are humanly
recognizable, which is essential given that humans are ultimately the decision-makers, even though
more and more tasks are carried out with the assistance of computers. Therefore, this document
provides two ways to indicate limit deviations:
a) classical graphical or symbolic representations;
b) natural language property items for data templates.
The illustrations included in this document are intended to illustrate the text and/or to provide
examples of the related technical drawing specification. These illustrations are not fully dimensioned
and toleranced, showing only the relevant general principles.
v
INTERNATIONAL STANDARD ISO 6284:2023(E)
Technical product documentation — Construction
documentation — Indication of limit deviations
1 Scope
This document specifies methods for the indication of limit deviations on construction documents.
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 286-1:2010, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes
— Part 1: Basis of tolerances, deviations and fits
ISO 6707-1:2020, Buildings and civil engineering works — Vocabulary — Part 1: General terms
ISO 9431, Construction drawings — Spaces for drawing and for text, and title blocks on drawing sheets
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 286-1 and ISO 6707-1 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
construction document
document which specifies construction information
Note 1 to entry: A construction document can be a drawing or a document used to convey or record construction
requirements.
Note 2 to entry: See ISO 5127:2017, 3.1.1.38 for more information about the term “document”.
3.2
data template
schema providing a data structure used to describe the properties of objects
[SOURCE: ISO 23387:2020, 3.3, modified — Definition revised, examples and notes to entry removed.]
3.3
limit deviation
upper limit deviation (3.4) or lower limit deviation (3.5) from target size (3.6)
Note 1 to entry: In this document, “target size” is used for applying deviations to comply with the conventions in
the built environment sector, while “nominal size” is commonly used in engineering fields.
Note 2 to entry: See ISO 6707-1:2020, 3.7.2.6 for more information about the term “deviation”.
[SOURCE: ISO 286-1:2010, 3.2.5, modified — Definition modified and notes to entry added.]
3.4
upper limit deviation
upper limit of size minus target size (3.6)
Note 1 to entry: Upper limit deviation is a signed value and may be negative, zero or positive.
[SOURCE: ISO 286-1:2010, 3.2.5.1, modified — Symbols and figure removed, definition modified.]
3.5
lower limit deviation
lower limit of size minus target size (3.6)
Note 1 to entry: Lower limit deviation is a signed value and may be negative, zero or positive.
[SOURCE: ISO 286-1:2010, 3.2.5.2, modified — Symbols removed and definition modified.]
3.6
target size
reference size used in design and in practice in order to indicate the size desired and to which the
deviations, which would ideally be zero, are to be related
[SOURCE: ISO 6707-1:2020, 3.7.2.12, modified — Note 1 to entry removed.]
4 General
4.1 Generality
4.1.1 A limit deviation shall be indicated on a construction document only when there is a functional
requirement to control position, dimension, orientation or form.
4.1.2 Target size shall be the only reference to limit deviation in construction documents.
NOTE The term “deviation” is defined in relation to “nominal size” in ISO 286-1. However, this term is
relevant to “desired value”, associated with the term “target size” in ISO 6707-1, which specifies a vocabulary for
the construction industry.
4.2 Application
Indication of limit deviations shall be applied using the following methods:
a) dimensions on construction drawings or figures within notes;
b) property items within data templates.
4.3 Designations of deviation types
An indication of limit deviations should clarify its type requirements with a designation, when
applicable. Designations of popular deviation types may follow Table 1 or the conventions of the
manufacturing industry.
Table 1 — Designations of popular deviation types
Deviation type Designation
Length deviation LD
Angular deviation AD
Profile deviation of a line PL
Straightness deviation of a line SL
TTabablele 1 1 ((ccoonnttiinnueuedd))
Deviation type Designation
Shape deviation of a surface SS
Flatness deviation of a surface FS
Skewness SK
Position deviation of a point PP
Position deviation of a line PL
Verticality deviation VD
Horizontality deviation HD
NOTE Deviation types listed in Table 1 are defined in ISO 6707-1 and the sequence of the items is the same as
that in ISO 6707-1.
5 Indication of limit deviations
5.1 As dimensions on construction drawings or figures within notes
5.1.1 A limit deviation shall be indicated numerically and be placed with, or adjacent to, the size
concerned in dimensions on construction drawings. A single reference within notes in the space for
text in accordance with ISO 9431 may applied in the case of repetitive deviations.
5.1.2 Limit deviations for size shall be indicated by the target size and the limit deviations. The target
size and the values of limit deviations shall be given in millimetres or metres (see Figures 1 and 2).
5.1.3 Limit deviation information which is shown on construction drawings should be given in
accordance with the example shown in Figure 1.
a) For asymmetrical limit deviations, information shall be specified by indicating the upper deviation
above the lower deviation, see Figure 1 a).
b) If one of the two limit deviations is zero, this shall be expressed explicitly by the digit zero without
a sign, see Figure 1 b).
c) If the tolerance is symmetrical in relation to the dimensional value, the limit deviation shall be
indicated only once, preceded by the plus-minus sign (±), see Figure 1 c).
a) b) c)
Figure 1 — Examples of indications of limit deviations for size
5.1.4 Limit deviations for a position may be indicated by limit deviations for a dimension which
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