1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationLibrary objects for architecture, engineering and construction Part 3: Shape and measurement Code of practiceBS 8541-3:2012BS 8541-3:2012Publishing and copyright informationThe B
2、SI copyright notice displayed in this document indicates when the document was last issued. The British Standards Institution 2012 Published by BSI Standards Limited 2012ISBN 978 0 580 74145 6ICS 01.100.30The following BSI references relate to the work on this standard: Committee reference B/555 Dra
3、ft for comment 12/30240257Publication historyFirst (present) edition September 2012Amendments issued since publicationDate Text affected The British Standards Institution 2012 iBS 8541-3:2012ContentsForeword iii1 Scope 12 Normative references 13 Terms and definitions 14 Shape and measurement levels
4、for construction library objects 25 Use of level of detail and level of measurement 4AnnexesAnnex A (informative) COBie 2.4 presentation 8Annex B (informative) ISO 10303-28 “XML” format 9Annex C (informative) BS ISO 10303-21 “STEP file” format 14Bibliography 15List of figuresFigure 1 Core maturity m
5、odel ivFigure 2 Schematic, coordinating and visualization levels of detail 2Figure 3 Relationship of type (library object and occurrence objects 7List of tablesTable 1 Expected levels of detail for construction library objects 5Table 2 Expected levels of detail for specific domains 5Table 3 Expected
6、 levels of measurement for construction library objects 6Table 4 Expected levels of measurement for specific domains 6Table A.1 COBie type sheet showing fields that relate to size-related columns 8Table A.2 COBie attribute sheet showing an example measure 8Table A.3 COBie coordinate sheet (showing c
7、omponent placement and extent 9Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 16, an inside back cover and a back cover.BS 8541-3:2012ii The British Standards Institution 2012This page deliberately left blank The British Standards Institution
8、2012 iiiBS 8541-3:2012ForewordPublishing informationThis part of BS 8541 is published by BSI Standards Limited, under licence from The British Standards Institution, and came into effect on 30 September 2012. It was prepared by Technical Committee B/555, Construction design, modelling and data excha
9、nge. A list of organizations represented on this committee can be obtained on request to its secretary.Relationship with other publicationsBS 8541 comprises four parts as follows: Part 1, Identification and classification Part 2, Recommended 2D symbols of building elements for use in building inform
10、ation modelling Part 3 (this part), Shape and measurement Part 4, Attributes for specification and assessment BS 8541-1, BS 8541-3 and BS 8541-4 document best practice for the development and application of construction library objects to support Building Information Modelling (BIM)-based design, st
11、andardization, specification and construction processes, see BS 8541-1:2012, 0.4 and Figure 1.The IFC standard (ISO/PAS 16739) includes recommendations for the association of base quantities and geometry for objects. The use of the IFC standard can be supplemented by using UK-specific quantification
12、 recommendations. For further information on work within ISO, see BS 8541-1:2012, Clause 0.Use of this documentAs a code of practice, this part of BS 8541 takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensu
13、re that claims of compliance are not misleading.Any user claiming compliance with this part of BS 8541 is expected to be able to justify any course of action that deviates from its recommendations.Presentational conventionsThe provisions in this standard are presented in roman (i.e. upright) type. I
14、ts recommendations are expressed in sentences in which the principal auxiliary verb is “should”.Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element.The word “should” is used to express recommendations of this stand
15、ard. The word “may” is used in the text to express permissibility, e.g. as an alternative to the primary recommendation of the clause. The word “can” is used to express possibility, e.g. a consequence of an action or an event.Notes and commentaries are provided throughout the text of this standard.
16、Notes give references and additional information that are important but do not form part of the recommendations. Commentaries give background information.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of a contract. Users are responsible
17、 for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS 8541-3:2012iv The British Standards Institution 2012Figure 1 Core maturity modelNOTE 1 Reproduced with kind permission of Mark Bew and Mervyn Richards.NOTE 2 The BIM reports and an update
18、d Roadmap are maintained by B/555 1)1)1)Available at: http:/ The British Standards Institution 2012 1BS 8541-3:20121 ScopeThis part of BS 8541 extends the recommendations in BS 8541-1 to cover purposes for characterizing the shape and measurement of construction library objects for use in the buildi
19、ng construction and facility domain. It applies to the creation and use of generic objects and manufacturers product objects.NOTE Providers of generic and manufacturers product objects can provide information to support additional purposes including measurement and spatial coordination.It gives reco
20、mmendations for the application of construction objects in integrated BIM working for spatial and construction coordination, quantity take-off and visualization. It defines the level of detail appropriate for specific uses and provides representations of measurements for characterizing the library o
21、bject where geometric shape is not relevant.Where a project is formally committed to integrated working, this British Standard may be adopted as a requirement on the design team and/or the procurement chain. For other situations, this British Standard gives recommendations of best practice.2 Normati
22、ve referencesThe following referenced documents are indispensable for the application 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.BS 8541-1:2012, Library objects for a
23、rchitecture, engineering and construction Part 1: Identification and classification Code of practice3 Terms and definitionsFor the purposes of this part of BS 8541, the terms and definitions given in BS 8541-1 and the following apply.3.1 object3.1.1 template objecttype object intended to guide the p
24、roduction of generic objects and product objects by providing schedules of classification values and a minimum set of attributesNOTE Typically the measurement type is specified, but the values are not.3.1.2 generic objecttype object intended for use in stages of design when the object is not resolve
25、d into a product3.1.3 product objecttype object intended to represent an obtainable product, either as a requirement or exemplar or as-built3.1.4 type (library) objectrepresentation of the common features of a product or group, including its classifications and propertiesNOTE 1 It can be a template
26、object, generic object or product object.NOTE 2 It is independent of any occurrence, and has no placement in space. It can represent a template, generic or product object.3.1.5 occurrence objectrepresentation of an actual occurrence (instance) of an object in a buildingBS 8541-3:20122 The British St
27、andards Institution 20123.2 level of detailcompleteness and accuracy of a virtual shape representation compared to the physical and functional characteristics of the actual object 3.3 level of measurementcompleteness and accuracy of a virtual measurement compared to the physical and functional chara
28、cteristics of the actual object 4 Shape and measurement levels for construction library objects4.1 Level of detail and shape types4.1.1 GeneralLibrary objects should be delivered with shape information appropriate to the intended uses, see Figure 2.NOTE Three levels of detail are defined in 4.1.2 to
29、 4.1.4.Figure 2 Schematic, coordinating and visualization levels of detaila) Schematic level of detailb) Coordinating level of detailc) Visualization level of detail The British Standards Institution 2012 3BS 8541-3:20124.1.2 Schematic level of detailA library object should be characterized by its e
30、xtent.NOTE 1 A schematic level of detail can be used to represent the extent of the object and its connectivity. The extent of an object can be a 3D bounding box, so its location, size and adjacencies are visible.A library object should be characterized by key connections and connectivity, using eit
31、her a wire-line representation, or specific connection points.NOTE 2 Schematic level of detail is broadly similar to the AIA Level of Development 200300 2.4.1.3 Coordinating level of detail For coordinating level of detail, a library object should also be characterized by more detailed shape suffici
32、ent to recognize the object and ensure that it has sufficient space allocated.NOTE 1 The purposes for coordinating level of detail include object recognition, spatial allocation and coordination, and clash detection. This level of detail is also useful for the visualization of space use and construc
33、tion processes.NOTE 2 Coordinating level of detail is broadly similar to the AIA Level of Development 300 2.NOTE 3 Excessive geometric detail in representations can be counterproductive and have an impact of model performance.4.1.4 Visualization level of detail For visualization, a library object sh
34、ould be characterized by more detailed shape sufficient to create a recognizable image and to envisage its operation and use.NOTE 1 The usecases for visualization level of detail include detailed rendering, and visualization of the usability of equipment, including the simulation of connections on e
35、quipment through named ports.NOTE 2 Visualization level of detail may be broadly similar to the AIA Level of Development 300 400 2.4.1.5 Insertion points Insertion points should be consistent across all levels of detail and should usually be within the extent of the object.4.2 Levels of measurement
36、and measurement types4.2.1 GeneralA library object should be characterized by its physical properties. Objects without specific sizing should be described at a unit size by volume, area, length or mass.For construction object templates, the type of measurement (e.g. linear, area, mass, power etc.) s
37、hould be defined. Any conventional preferences for particular units should be documented in the property description.For generic objects and product objects, units should be defined for any numeric attribute. Units for angles, length, area, volume and mass should be used consistently across shape an
38、d measurement.NOTE 1 BS ISO 800001 provides guidance on the naming of units of measure.BS 8541-3:20124 The British Standards Institution 2012NOTE 2 ISO/PAS 16739 provides guidance on the naming of measurement types and units of measure.NOTE 3 Three levels of measurement are defined in 4.2.2 to 4.2.4
39、.Nominal sizes should not be documented as actual measurements. 4.2.2 Characteristic level of measurement A library object should be characterized by its overall dimensions and mass.4.2.3 Standard level of measurement representation of measurements derived from the level of detail available To suppo
40、rt generalized measurements, a library object should be characterized by its principal dimensions, areas and volume.4.2.4 Method-based level of measurementTo support specific methods of measurement, a library object should additionally be characterized by method-based measures.NOTE 1 Methodbased mea
41、surements are typically made to a local or national methodology. The purposes for methodbased level of measurement includes contractually required early stage elemental cost plans , quantity takeoff reports, and Bills of Quantities prepared in accordance with standards such as RICS SMM73, NRM4 or IC
42、E CESMM4 5.A library object may also be characterized by its estimated or reference service life. Service lives should be given in years for passive objects and in hours for those objects whose service life depends on their use.NOTE 2 See ISO 156864 2).5 Use of level of detail and level of measureme
43、nt5.1 Use of level of detail 5.1.1 GeneralAn object should be characterized by a 3D representation of its shape, with a level of detail appropriate to its intended uses. The representation should be associated to the type object.NOTE See A.2, B.2 or C.2 for representation examples.5.1.2 Library obje
44、ct types Library templates should have a schematic level of detail.Generic objects should have a coordination level of detail.Products should have a coordination level of detail and may have a visualization level of detail.NOTE See Table 1 for the expected levels of detail for construction library o
45、bjects.2)In preparation. The British Standards Institution 2012 5BS 8541-3:2012Table 1 Expected levels of detail for construction library objectsSchematic Coordination VisualizationTemplate objects required optional optionalGeneric objects optional required optionalProduct objects optional required
46、optional5.1.3 DomainsLibrary objects for architectural and planning objects should have at least a coordination level of detail.Library objects for structural design in shared designs should have at least a coordination level of detail.Library objects for mechanical, electrical and plumbing design s
47、hould have at least a schematic level of detail.NOTE 1 See Table 2 for the expected levels of detail for specific domains.Table 2 Expected levels of detail for specific domainsSchematic Coordination VisualizationArchitecture and planningoptional required optionalStructural optional required optional
48、Mechanical, electrical and plumbingrequired required optionalCivil and infrastructurerequired required optionalNOTE 2 See A.2, B.2 or C.2 for examples.5.2 Use of levels of measurement5.2.1 GeneralAn object should be characterized by measurements, with a level of detail appropriate to its intended us
49、es and domain.The measurement should be associated to the type object.NOTE See A.3, B.3 or C.3 for measurement examples, including service life.5.2.2 Library object types Library templates should have a characteristic level of measurement.Generic library objects should have a characteristic and standard level of measurement.Product objects should have a characteristic, standard and method-based level of measurement.NOTE See Table 3 for the expected
