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Space Types Ontology

Release 01.12.2025

Latest version:
https://w3id.org/spot#
Revision:
1.0.0
Authors:
Anne Göbels,(Design Computation, RWTH Aachen)
Oliver Schulz,(Design Computation, RWTH Aachen)
Fabian Rolke,(Design Computation, RWTH Aachen)
Download serialization:
JSON-LD RDF/XML N-Triples TTL
License:
https://creativecommons.org/licenses/by/4.0 License
Visualization:
Visualize with WebVowl
Cite as:
Göbels, A., Schulz, O., & Rolke, F. (2025). Space Types Ontology (Version 1.0.0). https://w3id.org/spot (see BibTeX entry)
Ontology Specification Draft

Abstract

The Space Types Ontology (SPOT) is an OWL-based ontology for spatially representing and managing resources and data related to assets in the built environment. Built on the principle that all asset data carries an inherent spatial dimension, SPOT provides machine-readable expressions of spatial metadata and relationships, enabling querying and integration of heterogeneous data sources across an asset. Its modular design focuses on basic spatial types and simple relationships, allowing domain-specific extensions for more precise use cases. The SPOT Ontology is extended with the SPOT Axis Mapping Ontology and the SPOT Scene Graph Extension .

Introduction back to ToC

TheSpace Types Ontology (SPOT) provides a machine-readable, OWL-based representation of spatial metadata and relationships across an asset. It is built on the principle that all asset-related data carries an inherent spatial dimension. Even non-geometric data such as textual reports can be spatially contextualized through their references to specific components, zones, or areas. By establishing a common digital space for all asset data, SPOT enables the discovery of relationships between previously disconnected resources, supporting spatial querying and data integration.

SPOT follows a modular design, focusing on a minimal set of basic spatial types and relationships to enable broad applicability. It can be extended or combined with existing ontologies to support more precise, domain-specific use cases.

Namespace declarations

Table 1: Namespaces used in the document
spot<https://w3id.org/spot>
schema<http://schema.org>
owl<http://www.w3.org/2002/07/owl>
rdf<http://www.w3.org/1999/02/22-rdf-syntax-ns>
terms<http://purl.org/dc/terms>
xsd<http://www.w3.org/2001/XMLSchema>
rdfs<http://www.w3.org/2000/01/rdf-schema>
vann<http://purl.org/vocab/vann>
default namespace<https://w3id.org/spot>

SPOT Ontology: Overview back to ToC

This ontology has the following classes and properties.

Classes

Object Properties

Named Individuals

Cross reference for SPOT Ontology classes, properties and dataproperties back to ToC

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

Classes

Appearancec back to ToC or Class ToC

IRI: https://w3id.org/spot#Appearance

The appearance of an entity space in a reference space (Asset, Document or another Entity Space). The appearance object serves as a container/reference to assign spatial relation definitions for the relationship between the Entity Space instance and the space where it appears in.
has sub-classes
Asset Appearance c, Document Appearance c, Entity Appearance c
is in domain of
appears in op
is in range of
has appearance op

Area Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#AreaSpace

A two-dimensional space that can be used to represent resources like 2D drawings or maps
has super-classes
Entity Space c
has sub-classes
Horizontal Area Space c, Vertical Area Space c

Asset Appearancec back to ToC or Class ToC

IRI: https://w3id.org/spot#AssetAppearance

The appearance of entity space in an asset space
has super-classes
Appearance c

Asset Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#AssetSpace

"The Asset Space represents the actual, physical asset. An instance of the Asset Space is the superordinate object for the spatial superimposition of Entity Space instances.
has super-classes
Physical Space c

Axisc back to ToC or Class ToC

IRI: https://w3id.org/spot#Axis

An axis of the local coordinate system of a space instance
is in range of
has X axis op, has Y axis op, has Z axis op, has axis op

Directionc back to ToC or Class ToC

IRI: https://w3id.org/spot#Direction

The defined direction of an axis (e.g., an X-Axis is pointing to the 'Front' of the asset, or an Y-Axis is pointing to the 'Bottom' of a document / plan ). Only Asset Space or Document Space Axis should get an Direction Definition.
is in domain of
is inverse direction of op
is in range of
has direction op, is inverse direction of op
has members
Bottom ni, Front ni, Left ni, Rear ni, Right ni, Top ni

Document Appearancec back to ToC or Class ToC

IRI: https://w3id.org/spot#DocumentAppearance

The appearance of an entity space in a document space
has super-classes
Appearance c

Document Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#DocumentSpace

The Document Space represents the extent of a document or file that contains Entity Spaces. A Document Space can represent different, disjointed Entity Spaces, such as a collection of sections and details on a construction plan.
has super-classes
Virtual Space c

Entity Appearancec back to ToC or Class ToC

IRI: https://w3id.org/spot#EntityAppearance

The appearance of an entity space in another (parent/super) entity space
has super-classes
Appearance c

Entity Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#EntitySpace

The Entity Space is a coherent unit of information covered by a single resource, such as a 3D model, a 2D drawing, or a picture, representing its actual dimensions referring to the Asset Space.
has super-classes
Physical Space c
has sub-classes
Area Space c, Line Space c, Point Space c, Volume Space c
is in domain of
has appearance op

Horizontal Area Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#HorizontalAreaSpace

The Horizontal Area Space is a subtype of Area Space, that implies that the plane of the resource is parallel to the horizontal plane of the asset space. Floorplans or maps are typical horizontal area spaces.
has super-classes
Area Space c

Line Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#LineSpace

A one-dimensional space that can be used to represent e.g., vertical height references such as water levels
has super-classes
Entity Space c

Physical Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#PhysicalSpace

The Physical Space is the superclass for the global, asset and entity spaces, which implies that these spaces are can be directly mapped in physical space, as opposite to virtual spaces. It is an abstract class and should not be used directly.
has super-classes
Space c
has sub-classes
Asset Space c, Entity Space c

Point Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#PointSpace

The Point Space can represent resources that only need one point of reference, such as the camera position of a picture or the position of a sensor.
has super-classes
Entity Space c

Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#Space

The abstract superclass for all defined space types.
has sub-classes
Physical Space c, Virtual Space c
is in domain of
has X axis op, has Y axis op, has Z axis op, has axis op, has subspace op, has super space op, represents op
is in range of
appears in op, has subspace op, has super space op

Vertical Area Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#VerticalAreaSpace

The Vertical Area Space is a subtype of Area Space, that implies that the plane of the resource is parallel to the vertical axis of the asset space. Section drawings are typical vertical area spaces.
has super-classes
Area Space c

Virtual Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#VirtualSpace

The Virtual Space represent resource spaces, which cannot be directly mapped to the real physical space, as their spatial arrangement is artificial. For example 2D plans with a collection of drawings or a file containing multiple disjointed 3D models of the same asset. It is an abstract class and should not be used directly.
has super-classes
Space c
has sub-classes
Document Space c

Volume Spacec back to ToC or Class ToC

IRI: https://w3id.org/spot#VolumeSpace

The Volume Space can represent three-dimensional resources, such as 3D models or point clouds.
has super-classes
Entity Space c

Object Properties

appears inop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#appearsIn

Relates an appearance to the space in which it appears
has domain
Appearance c
has range
Space c

has appearanceop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasAppearance

Relates an Entity space to an appearance object
has domain
Entity Space c
has range
Appearance c

has axisop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasAxis

Relates a space to an axis
has sub-properties
has X axis op, has Y axis op, has Z axis op
has domain
Space c
has range
Axis c

has directionop back to ToC or Object Property ToC

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

Defines the direction of an axis. Should only be used for axes of Asset or Document Spaces.
has domain
Axis c and (inverse has axis op some Asset Space c or Document Space c)
has range
Direction c

has subspaceop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasSubspace

Relates a space to a space it contains
has domain
Space c
has range
Space c
is inverse of
has super space op

has super spaceop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasSuperSpace

"Relates a space to its containing/parent/super space. This property can be derived by the propert chain: spaceA <hasAppearance> AppearanceX <appearsIn> spaceB
has domain
Space c
has range
Space c
is inverse of
has subspace op
has sub-property chains
has appearance op o appears in op

has X axisop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasXAxis

Relates a space to its X axis
has super-properties
has axis op
has domain
Space c
has range
Axis c

has Y axisop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasYAxis

Relates a space to its Y axis
has super-properties
has axis op
has domain
Space c
has range
Axis c

has Z axisop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#hasZAxis

Relates a space to its Z axis
has super-properties
has axis op
has domain
Space c
has range
Axis c

is inverse direction ofop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#isInverseDirectionOf

Links to inverse directions to each other, eg. Front - Rear.
has domain
Direction c
has range
Direction c

representsop back to ToC or Object Property ToC

IRI: https://w3id.org/spot#represents

Relates a SPOT space to the resource it spatially describes (the referent). The space may describe the spatial extent or location of the referent wholly or in part. Several spaces may represent the same referent, either as alternative descriptions or as parts of a decomposition. No completeness is implied: a single space does not necessarily cover the entire referent. The range is intentionally open, so that the referent can originate from any vocabulary.
has domain
Space c
has range
Resource c

Named Individuals

Bottomni back to ToC or Named Individual ToC

IRI: https://w3id.org/spot#Bottom

The bottom of an asset or document space
belongs to
Direction c
has facts
is inverse direction of op Top

Frontni back to ToC or Named Individual ToC

IRI: https://w3id.org/spot#Front

The front of an asset or document space.
belongs to
Direction c
has facts
is inverse direction of op Rear

Leftni back to ToC or Named Individual ToC

IRI: https://w3id.org/spot#Left

The left of an asset or document space
belongs to
Direction c
has facts
is inverse direction of op Right

Rearni back to ToC or Named Individual ToC

IRI: https://w3id.org/spot#Rear

The rear of an asset or document space
belongs to
Direction c
has facts
is inverse direction of op Front

Topni back to ToC or Named Individual ToC

IRI: https://w3id.org/spot#Top

The top of an asset or document space
belongs to
Direction c
has facts
is inverse direction of op Bottom

Legend back to ToC

c: Classes
op: Object Properties
dp: Data Properties
ni: Named Individuals

References back to ToC

Göbels, A., Schulz, O., & Beetz, J. (2024). Towards a Common Digital Space: Proposing a Schema for Spatially Linking Heterogeneous Resources. Proceedings of the 41st International Conference of CIB W78. https://itc.scix.net/paper/w78-2024-13

Acknowledgements back to ToC

The SPOT Ontology was developed during the SPP 100+ Spacelink and Spatio-B-RAG Project funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Germany – Project numbers 501812634 and 562882930.

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.