BIM Collaboration Format Ontology
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BIM Collaboration Format Ontology

Modified on: 2026-10-07
This version:
https://w3id.org/bcfOWL/1.0.0
Latest version:
https://w3id.org/bcfOWL
Previous version:
http://lbd.arch.rwth-aachen.de/bcfOWL#
Revision:
1.0.0
Issued on:
2026-10-07
Authors:
Oliver Schulz, Design Computation, RWTH Aachen University
Jyrki Oraskari, Design Computation, RWTH Aachen University
Jakob Beetz, Design Computation, RWTH Aachen University
Publisher:
Jyrki Oraskari
See also:
https://lbd.arch.rwth-aachen.de/bcfOWL_V1/index-en.html
Download serialization:
JSON-LD RDF/XML N-Triples TTL
License:
https://creativecommons.org/licenses/by/4.0/
Cite as:
Schulz, O., Oraskari, J., & Beetz, J. (2026). bcfOWL: BIM Collaboration Format Ontology (Version 1.0.0) [Ontology]. Design Computation, RWTH Aachen University. https://w3id.org/bcfOWL
Incompatible with:
http://lbd.arch.rwth-aachen.de/bcfOWL#
Ontology Specification Draft

Abstract

bcfOWL represents the BIM Collaboration Format (BCF) in RDF. It does not translate the BCF schema one to one. It composes BCF from established vocabularies (SOSA, SPOT, PROV-O, DCAT, SKOS, Dublin Core) and keeps only the coordination concepts that no other vocabulary covers, such as Topic, Comment, Viewpoint, and the visual state.

Introduction back to ToC

The BIM Collaboration Format (BCF) links issues to building models without storing the models. bcfOWL represents BCF in RDF. It does not translate the BCF schema one to one. It composes BCF from established vocabularies and keeps only the concepts that are specific to BCF coordination.

BCF is an open standard of buildingSMART. It has two technical parts: the BCF-XML file format, which exchanges issues as files, and the BCF API, a REST interface for issue servers. See also the BCF overview at buildingSMART. bcfOWL covers the data model that both parts share.

A photograph, a camera pose, or a damage record can therefore exist in the graph without a BCF context. A BCF Topic or Viewpoint can refer to it later. If the BCF statements are removed from the graph, the referenced resources stay describable with the generic vocabularies alone.

The structural rules of BCF (for example, that a Topic has exactly one title) are not OWL axioms in this ontology. They are in a separate SHACL profile, bcfOWL-shapes, which checks a dataset under the closed-world assumption.

Previous version

Version 1.0.0 uses the namespace https://w3id.org/bcfOWL#. The last published version, 0.7.1 (2022-03-16), uses the namespace http://lbd.arch.rwth-aachen.de/bcfOWL#. Its documentation is at lbd.arch.rwth-aachen.de/bcfOWL_V1 (DOI 10.5281/zenodo.4710742). Data that uses the 0.7.1 terms needs a migration, because later versions removed and renamed terms. The changes and a migration table are in the change log.

Namespace declarations

Table 1: Namespaces used in the document
bcfOWL<https://w3id.org/bcfOWL#>
sosa<http://www.w3.org/ns/sosa/>
spot<https://w3id.org/spot#>
bot<https://w3id.org/bot#>
prov<http://www.w3.org/ns/prov#>
dcat<http://www.w3.org/ns/dcat#>
skos<http://www.w3.org/2004/02/skos/core#>
dcterms<http://purl.org/dc/terms/>
owl<http://www.w3.org/2002/07/owl#>
rdf<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
rdfs<http://www.w3.org/2000/01/rdf-schema#>
xsd<http://www.w3.org/2001/XMLSchema#>
vann<http://purl.org/vocab/vann/>
schema<http://schema.org/>

bcfOWL: Overview back to ToC

This ontology has the following classes and properties.

Classes

Object Properties

Data Properties

bcfOWL: Description back to ToC

Composition over translation

bcfOWL follows one delegation rule. A BCF concept is delegated to an existing vocabulary if an established vocabulary covers its meaning without a shift. It stays in bcfOWL if no such vocabulary exists, or if BCF adds conditions that the other vocabulary does not express.

Delegated concepts

bcfOWL reuses the following vocabularies. It uses their terms by IRI and does not import them.

The concepts are delegated as follows.

Format-specific core

The core contains the coordination concepts bcfOWL:Project, bcfOWL:Topic, bcfOWL:Comment, and bcfOWL:Viewpoint, and the visual state of a Viewpoint: selection, visibility and exceptions, components, coloring, lines, clipping planes, and bitmaps. The visual state contains instructions for a viewer, not statements about the building. bcfOWL therefore represents it directly, without more semantics.

Structural constraints

bcfOWL contains no cardinality restrictions. Under the open-world assumption, a missing title does not violate owl:minCardinality 1, and two status values are inferred to be the same individual. The BCF structure is a format requirement, not a statement about the world. It is therefore checked with the SHACL profile bcfOWL-shapes.

Examples

These Turtle files use the namespace https://example.org/bcfowl-example#. They build on each other.

Cross-reference for bcfOWL classes, object properties and data properties back to ToC

This section provides details for each class and property defined by bcfOWL.

Classes

Bitmapc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Bitmap

Viewpoint-internal placement of an externally represented bitmap image.
is in domain of
has Bitmap Image op, has Height dp, has Location dp, has Normal dp, has Up Vector dp
is in range of
has Bitmap op

Clipping Planec back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#ClippingPlane

Viewpoint-internal blank-node markup defining a plane by a location and a direction toward the clipped half-space.
is in domain of
has Direction dp, has Location dp
is in range of
has Clipping Plane op

Coloringc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Coloring

Viewpoint-internal blank-node relation mapping an RGB or ARGB color to one or more Components.
is in domain of
has Color dp, has Component op
is in range of
has Coloring op

Commentc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Comment

A comment related to a topic. Its purpose is to record discussion between different parties related to the topic.
is in domain of
has Comment Text dp, has Project op, has Topic op, has Viewpoint op, modified by op

Componentc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Component

Stable BCF component descriptor linking to a building element and retaining round-trip identifiers.
is in domain of
has Authoring Tool Id dp, has Element op, has Ifc Guid dp, has Originating System op
is in range of
has Component op, has Selected Component op, has Visibility Exception op

Extension Schemac back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#ExtensionSchema

The extension schema defines the allowed values of a BCF project: one skos:ConceptScheme each for type, status, label, priority and stage. A value belongs to its scheme with skos:inScheme.
is in domain of
has Label Scheme op, has Priority Scheme op, has Stage Scheme op, has Status Scheme op, has Type Scheme op, has User op
is in range of
has Extension Schema op

Labelc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Label

Tag for categorizing issues.
has super-classes
Concept c
is in range of
has Label op

Linec back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Line

Viewpoint-internal blank-node markup defined by start and end points; equal endpoints represent point-like markup.
is in domain of
has End Point dp, has Start Point dp
is in range of
has Line op

Originating Systemc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#OriginatingSystem

Software with which the respective element was created.
is in range of
has Originating System op

Priorityc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Priority

Indication of the priority of an issue.
has super-classes
Concept c
is in range of
has Priority op

Projectc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Project

The project contains reference information about the project the topics belong to. It refers to the extension schema.
is in domain of
has Extension Schema op, reference space op
is in range of
has Project op

Stagec back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Stage

Project stage this topic relates to.
has super-classes
Concept c
is in range of
has Stage op

Topicc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Topic

Contains the reference information of a topic (a BCF issue). The BCF GUID is its dcterms:identifier.
is in domain of
has Assigned To op, has Due Date dp, has Index dp, has Label op, has Priority op, has Project op, has Stage op, has Topic Status op, has Topic Type op, has reference link op, modified by op
is in range of
has Topic op

Topic Statusc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#TopicStatus

Status of the issue, e.g. Open, In Progress, Closed.
has super-classes
Concept c
is in range of
has Topic Status op

Topic Typec back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#TopicType

Use case of a BCF issue, e.g. Information Request, Defect.
has super-classes
Concept c
is in range of
has Topic Type op

Viewpointc back to ToC or Class ToC

IRI: https://w3id.org/bcfOWL#Viewpoint

A viewpoint belongs to a topic and can be referred to by comments. It refers to the camera (a sosa:Observation) and carries the visual state: selection, visibility, coloring, clipping planes, lines and bitmaps. A viewpoint does not change after creation.The coordinates of the visual state are in the space given by spot:appearsIn of the camera pose. See the change log for the camera frame.
is in domain of
has Bitmap op, has Clipping Plane op, has Coloring op, has Default Visibility dp, has Index dp, has Line op, has Orthogonal Camera op, has Perspective Camera op, has Project op, has Selected Component op, has Snapshot op, has Topic op, has Visibility Exception op, openings Visible dp, space Boundaries Visible dp, spaces Visible dp
is in range of
has Viewpoint op

Object Properties

has Assigned Toop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasAssignedTo

The agent to whom this topic is assigned, expected to be one of the project's hasUser agents. A forward-looking responsibility, not provenance.
has domain
Topic c
has range
Agent c

has Bitmapop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasBitmap

has domain
Viewpoint c
has range
Bitmap c

has Bitmap Imageop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasBitmapImage

External binary image represented as a DCAT Dataset with a Distribution.
has domain
Bitmap c
has range
Dataset c

has Clipping Planeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasClippingPlane

has domain
Viewpoint c
has range
Clipping Plane c

has Coloringop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasColoring

has domain
Viewpoint c
has range
Coloring c

has Componentop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasComponent

Component included in a Coloring resource.
has domain
Coloring c
has range
Component c

has Elementop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasElement

Linked data reference to the building element.
has domain
Component c
has range
Element c

has Extension Schemaop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasExtensionSchema

URI to the extension schema.
has domain
Project c
has range
Extension Schema c

has Labelop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasLabels

has domain
Topic c
has range
Label c

has Label Schemeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasLabelScheme

The project's scheme of allowed Label values.
has domain
Extension Schema c
has range
Concept Scheme c

has Lineop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasLine

has domain
Viewpoint c
has range
Line c

has Originating Systemop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasOriginatingSystem

has domain
Component c
has range
Originating System c

has Orthogonal Cameraop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasOrthogonalCamera

has domain
Viewpoint c
is also defined as
data property

has Perspective Cameraop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasPerspectiveCamera

has domain
Viewpoint c
is also defined as
data property

has Priorityop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasPriority

has domain
Topic c
has range
Priority c

has Priority Schemeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasPriorityScheme

The project's scheme of allowed Priority values.
has domain
Extension Schema c
has range
Concept Scheme c

has Projectop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasProject

Reference to the corresponding Project.
has domain
Comment c or Topic c or Viewpoint c
has range
Project c

has Selected Componentop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasSelectedComponent

A component selected in this viewpoint; repeated statements represent the BCF selection array.
has domain
Viewpoint c
has range
Component c

has Snapshotop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasSnapshot

Optional denormalized shortcut to the snapshot image for BCF serialization. The same media is otherwise the referenced observation's sosa:hasResult.
has domain
Viewpoint c
has range
Dataset c

has Stageop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasStage

has domain
Topic c
has range
Stage c

has Stage Schemeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasStageScheme

The project's scheme of allowed Stage values.
has domain
Extension Schema c
has range
Concept Scheme c

has Status Schemeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasStatusScheme

The project's scheme of allowed TopicStatus values.
has domain
Extension Schema c
has range
Concept Scheme c

has Topicop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasTopic

Link to the relating topic.
has domain
Comment c or Viewpoint c
has range
Topic c

has Topic Statusop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasTopicStatus

has domain
Topic c
has range
Topic Status c

has Topic Typeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasTopicType

has domain
Topic c
has range
Topic Type c

has Type Schemeop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasTypeScheme

The project's scheme of allowed TopicType values.
has domain
Extension Schema c
has range
Concept Scheme c

has Userop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasUser

An agent valid in this project; the BCF 3.0 'users' list from which creators and assignees are drawn.
has domain
Extension Schema c
has range
Agent c

has Viewpointop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasViewpoint

Reference to the viewpoint this comment relates to.
has domain
Comment c
has range
Viewpoint c

has Visibility Exceptionop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#hasVisibilityException

A component whose visibility is inverted after defaults and view-setup hints are applied.
has domain
Viewpoint c
has range
Component c

modified byop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#modifiedBy

The agent of the latest modification (the BCF field ModifiedAuthor). A shortcut for the BCF round trip. The full history is in the provenance statements.
has domain
Comment c or Topic c
has range
Agent c

reference spaceop back to ToC or Object Property ToC

IRI: https://w3id.org/bcfOWL#referenceSpace

The spot:AssetSpace in which BCF API coordinates for this Project are exposed and accepted.
has domain
Project c
has range
Asset Space c

Data Properties

has Aspect Ratiodp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasAspectRatio

Width-to-height ratio of the perspective or orthogonal camera observation.
has domain
Observation c
has range
double

has Authoring Tool Iddp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasAuthoringToolId

has super-properties
identifier dp
has domain
Component c
has range
string

has Colordp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasColor

Six-digit RGB or eight-digit ARGB hexadecimal color as defined by BCF.
has domain
Coloring c
has range
string

has Comment Textdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasCommentText

The comment text. Mutable; history is statement-level.
has domain
Comment c
has range
string

has Default Visibilitydp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasDefaultVisibility

Default visibility state before view-setup hints and visibility exceptions are applied.
has domain
Viewpoint c
has range
boolean

has Directiondp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasDirection

has domain
Clipping Plane c
has range
3D vector ep

has Due Datedp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasDueDate

Date until when the topic's issue needs to be resolved.
has domain
Topic c
has range
date Time

has End Pointdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasEndPoint

has domain
Line c
has range
3D point ep

has Field of Viewdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasFieldOfView

Camera field of view angle in degrees, for a perspective observation.
has domain
Observation c
has range
double

has Heightdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasHeight

Bitmap height in metres.
has domain
Bitmap c
has range
double

has Ifc Guiddp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasIfcGuid

The IFC GUID of the component, used as a fallback when no linked data URI is available.
has super-properties
identifier dp
has domain
Component c
has range
string

has Indexdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasIndex

Optional number used to maintain the order of Topics or Viewpoints.
has domain
Topic c or Viewpoint c
has range
integer

has Locationdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasLocation

has domain
Bitmap c or Clipping Plane c
has range
3D point ep

has Normaldp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasNormal

has domain
Bitmap c
has range
3D vector ep

has Orthogonal Cameraop back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasOrthogonalCamera

has range
Observation c
is also defined as
object property

has Perspective Cameraop back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasPerspectiveCamera

has range
Observation c
is also defined as
object property

has Start Pointdp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasStartPoint

has domain
Line c
has range
3D point ep

has Up Vectordp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasUpVector

has domain
Bitmap c
has range
3D vector ep

has View To World Scaledp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#hasViewToWorldScale

Proportion of view to model, for an orthogonal observation.
has domain
Observation c
has range
double

openings Visibledp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#openingsVisible

Explicit view-setup override for opening components, applied after default visibility.
has domain
Viewpoint c
has range
boolean

space Boundaries Visibledp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#spaceBoundariesVisible

Explicit view-setup override for space-boundary components, applied after default visibility.
has domain
Viewpoint c
has range
boolean

spaces Visibledp back to ToC or Data Property ToC

IRI: https://w3id.org/bcfOWL#spacesVisible

Explicit view-setup override for spatial components, applied after default visibility.
has domain
Viewpoint c
has range
boolean

Legend back to ToC

c: Classes
op: Object Properties
dp: Data Properties
ep: External Properties
null

Acknowledgments back to ToC

bcfOWL was developed at Design Computation, RWTH Aachen University.

The previous versions of bcfOWL were part of research that was funded by the EU through the H2020 project BIM4REN.

The authors would like to thank Silvio Peroni for developing LODE, a Live OWL Documentation Environment, which is used for representing the Cross Referencing Section of this document and Daniel Garijo for developing Widoco, the program used to create the template used in this documentation.