Historic Structure Ontology (HSTO)
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Historic Structure Ontology (HSTO)

Latest version:
https://w3id.org/hsto#
Revision:
1.0.0
Authors:
Maria Laura Leonardi
Stefano Cursi
Letizia Martinelli
Elena Gigliarelli
Miguel Azenha
Daniel V. Oliveira
Imported Ontologies:
beo#
dot#
Download serialization:
JSON-LD RDF/XML N-Triples TTL
License:
https://creativecommons.org/licenses/by/4.0/
Visualization:
Visualize with WebVowl
Cite as:
Maria Laura Leonardi, Stefano Cursi, Letizia Martinelli, Elena Gigliarelli, Miguel Azenha, Daniel V. Oliveira. Historic Structure Ontology (HSTO). Revision: 1.0.0.
Ontology Specification Draft
The Historic Structure Ontology (HSTO) provides a formal knowledge representation of the physical configuration of historic masonry aggregates, explicitly modelling the relationships among their structural components. The ontology introduces hsto:StructuralPart as its central class, from which two main subclasses are derived: hsto:Facade and hsto:HorizontalStructure. Facades are further linked to historic openings and their heritage-specific components — jambs, sills, lintels, arches — extending standard BIM schemas with historically grounded construction details. Horizontal structures are decomposed into timber floors and masonry vaults, with timber floors further articulated into beams, joists, and planks. HSTO also models structural connections as explicit first-class objects, with two prevalent subtypes — quoins and ties — and a connection quality property to support FEM modelling strategies. Each structural part can be associated with datation information, accessibility assessments, damage instances (via DOT), and traditional construction techniques (via HSV), enabling a comprehensive and interoperable description of historic masonry buildings for structural analysis and heritage documentation.
The structural characterisation of historic masonry buildings requires the representation of building elements and construction details that are systematically absent from modern digital construction schemas such as IFC. Features such as quoins, relieving arches, historic openings with their datation, and the variety of horizontal structural assemblies found in historic fabrics — from timber floors to masonry vaults — demand a dedicated ontological framework that goes beyond what standard BIM vocabularies currently offer. The Historic Structure Ontology (HSTO) addresses this gap by providing a formal representation of the physical configuration of masonry aggregates and the relationships among their structural components. The ontology is organised around the class hsto:StructuralPart, which serves as the main category for modelling individual structural components. From this class, two primary subclasses are derived: hsto:Facade, which captures the exterior wall surface of a structural unit including its opening layout and masonry typology, and hsto:HorizontalStructure, which models floor and roof assemblies providing diaphragm rigidity to the aggregate. HSTO introduces structural connections as explicit first-class objects rather than implicit geometric contacts, allowing the qualitative assessment of connection effectiveness to directly inform structural modelling choices. The ontology further enriches standard BIM entities from the Building Element Ontology (BEO) with heritage-specific opening components — sill, jamb, lintel, arch — and links structural parts to damage descriptions via the Damage Typology Ontology (DOT) and to traditional construction techniques via the Historic Survey Ontology (HSV). HSTO is published at https://w3id.org/hsto and is available in Turtle serialisation under a Creative Commons Attribution 4.0 licence. This ontology was developed in the context of the following research: Cursi, S., Martinelli, L., Gigliarelli, E., Leonardi, M. L., Azenha, M., & Oliveira, D. V. (2025). Leveraging linked data for enhanced knowledge representation in historical centers safety assessment: insights from Castelnuovo di Porto, Rome. Archeologia e Calcolatori, Supplemento 13, 217–231. https://doi.org/10.19282/acs.13.2025.16

Historic Structure Ontology (HSTO): Overview back to ToC

This ontology has the following classes and properties.

Classes

Object Properties

Data Properties

Named Individuals

Historic Structure Ontology (HSTO): Description back to ToC

The Historic Structure Ontology (HSTO) provides a formal representation of the physical configuration of masonry aggregates by explicitly modelling the relationships among their structural components, including facades, horizontal structures, openings, and connections.

Cross-reference for Historic Structure Ontology (HSTO) classes, object properties and data properties back to ToC

This section provides details for each class and property defined by Historic Structure Ontology (HSTO).

Classes

Archc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Arch

A curved spanning element closing the top of a historic opening, typically featuring a keystone.
has super-classes
Header c
is in range of
has opening component op

Connectionc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Connection

An explicit first-class object representing the physical interface between exactly two structural parts, enabling qualitative assessment of connection effectiveness.
has sub-classes
Quoin c, Tie c
is in domain of
has connection quality dp
is in range of
is connected to op

Facadec back to ToC or Class ToC

IRI: https://w3id.org/hsto#Facade

A distinct structural object representing the exterior wall surface of a structural unit, capturing opening layout regularity, masonry typology variations, and damage patterns.
has super-classes
Structural Part c
is in domain of
has height dp, has historic opening op, has length dp, is made of op

Historic Openingc back to ToC or Class ToC

IRI: https://w3id.org/hsto#HistoricOpening

A wall opening considered historic, associated with both relative and absolute dating, whose configuration is relevant for seismic assessment.
is in domain of
has absolute datation dp, has relative datation dp, is hosted by door op, is hosted by window op
is in range of
has historic opening op

Horizontal Structurec back to ToC or Class ToC

IRI: https://w3id.org/hsto#HorizontalStructure

A horizontal structural element such as a floor or roof assembly, providing diaphragm rigidity to the masonry aggregate.
has super-classes
Structural Part c
has sub-classes
Timber Floor c, Vault c
is in domain of
is covered by op, stiffness dp

Jambc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Jamb

The vertical side framing element of a historic opening.
has super-classes
Building Element Part c
is in range of
has opening component op

Joistc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Joist

A secondary timber element spanning between main beams or walls, supporting the floor planking.
is in range of
has joist op

Lintelc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Lintel

A flat horizontal spanning element closing the top of a historic opening.
has super-classes
Header c
is in range of
has opening component op

Main Beamc back to ToC or Class ToC

IRI: https://w3id.org/hsto#MainBeam

A primary timber beam supporting smaller joists in a timber floor assembly.
is in range of
has main beam op

Plankc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Plank

A timber plank forming the floor deck, providing diaphragm rigidity when overlaid.
is in range of
has plank op

Quoinc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Quoin

A connection formed by regularly cut interlocking corner stones providing enhanced mechanical interlocking between orthogonal walls.
has super-classes
Connection c

Sillc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Sill

The base threshold element of a historic opening.
has super-classes
Building Element Part c
is in range of
has opening component op

Structural Partc back to ToC or Class ToC

IRI: https://w3id.org/hsto#StructuralPart

The main category for modelling individual structural components of a historic masonry aggregate, exhibiting material and construction homogeneity.
has sub-classes
Facade c, Horizontal Structure c
is in domain of
has absolute datation dp, has accessibility dp, has damage op, has relative datation dp, is built with traditional construction technique op, is connected to op

Tiec back to ToC or Class ToC

IRI: https://w3id.org/hsto#Tie

A connection formed by metallic or wooden anchors used to tie structural parts together in historic masonry construction.
has super-classes
Connection c

Timber Floorc back to ToC or Class ToC

IRI: https://w3id.org/hsto#TimberFloor

A horizontal structural assembly composed of timber elements such as beams, joists, and planks.
has super-classes
Horizontal Structure c
is in domain of
has joist op, has main beam op, has plank op

Vaultc back to ToC or Class ToC

IRI: https://w3id.org/hsto#Vault

A masonry vault used as a horizontal structural element, typically in lower storeys. Kept generic at TBox level; specific vault typologies are articulated at ABox level through hsto:VaultPart instances.
has super-classes
Horizontal Structure c
is in domain of
has vault part op

Vault Partc back to ToC or Class ToC

IRI: https://w3id.org/hsto#VaultPart

A constituent part of a masonry vault, used at ABox level to articulate specific vault typologies and geometries.
is in range of
has vault part op

Object Properties

has damageop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasDamage

Associates a structural part with one or more damage instances described using the Damage Typology Ontology (DOT).
has domain
Structural Part c
has range
Damage c

has historic openingop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasHistoricOpening

Links a facade to one or more historic openings present on its surface.
has domain
Facade c
has range
Historic Opening c

has joistop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasJoist

Links a timber floor to its joist elements.
has domain
Timber Floor c
has range
Joist c

has main beamop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasMainBeam

Links a timber floor to its primary beam elements.
has domain
Timber Floor c
has range
Main Beam c

has opening componentop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasOpeningComponent

Links a BEO building element part to a heritage-specific opening component (sill, jamb, header, lintel, arch).
has domain
Building Element Part c
has range
Arch c or Header c or Jamb c or Lintel c or Sill c

has plankop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasPlank

Links a timber floor to its plank elements forming the floor deck.
has domain
Timber Floor c
has range
Plank c

has vault partop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#hasVaultPart

Links a vault to its constituent parts, articulated at ABox level to capture specific typologies and geometries.
has domain
Vault c
has range
Vault Part c

is built with traditional construction techniqueop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#isBuiltWithTraditionalConstructionTechnique

Links a structural part to a traditional construction technique as documented in the HSV ontology.
has domain
Structural Part c
has range
Traditional Construction Technique c

is connected toop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#isConnectedTo

Links a structural part to a connection instance representing the physical interface with another structural part.
has domain
Structural Part c
has range
Connection c

is covered byop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#isCoveredBy

Links a horizontal structure to the BEO covering element (floor finish or roof covering) overlying it.
has domain
Horizontal Structure c
has range
Covering c

is hosted by doorop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#isHostedByDoor

Links a historic opening to the BEO door element that hosts it.
has domain
Historic Opening c
has range
Door c

is hosted by windowop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#isHostedByWindow

Links a historic opening to the BEO window element that hosts it.
has domain
Historic Opening c
has range
Window c

is made ofop back to ToC or Object Property ToC

IRI: https://w3id.org/hsto#isMadeOf

Links a facade to the masonry wall instances that compose it, each corresponding to a portion with homogeneous geometric and constructional characteristics.
has domain
Facade c
has range
Masonry Wall c

Data Properties

has absolute datationdp back to ToC or Data Property ToC

IRI: https://w3id.org/hsto#hasAbsoluteDatation

Records the absolute construction date or date range of a structural part or historic opening.
has domain
Historic Opening c or Structural Part c
has range
string

has accessibilitydp back to ToC or Data Property ToC

IRI: https://w3id.org/hsto#hasAccessibility

Indicates whether a structural part is accessible for detailed survey, helping quantify the level of structural knowledge available.
has domain
Structural Part c
has range
boolean

has connection qualitydp back to ToC or Data Property ToC

IRI: https://w3id.org/hsto#hasConnectionQuality

A qualitative assessment of connection effectiveness (e.g. good/poor) used to inform modelling strategies such as rigid vs. flexible connections in FEM analysis.
has domain
Connection c
has range
string

has heightdp back to ToC or Data Property ToC

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

The height of a facade, in metres.
has domain
Facade c
has range
decimal

has lengthdp back to ToC or Data Property ToC

IRI: https://w3id.org/hsto#hasLength

The length of a facade, in metres.
has domain
Facade c
has range
decimal

has relative datationdp back to ToC or Data Property ToC

IRI: https://w3id.org/hsto#hasRelativeDatation

Records the relative construction chronology of a structural part or historic opening with respect to adjacent elements.
has domain
Historic Opening c or Structural Part c
has range
string

stiffnessdp back to ToC or Data Property ToC

IRI: https://w3id.org/hsto#stiffness

A qualitative or quantitative measure of the in-plane stiffness of a horizontal structural element (e.g. rigid/flexible).
has domain
Horizontal Structure c
has range
string

Named Individuals

hstoni back to ToC or Named Individual ToC

IRI: https://w3id.org/hsto

Legend back to ToC

c: Classes
op: Object Properties
dp: Data Properties
ni: Named Individuals
Cursi, S., Martinelli, L., Gigliarelli, E., Calcerano, F., Leonardi, M. L., Azenha, M., Oliveira, D. V., & Calvano, M. (2025). Leveraging linked data for enhanced knowledge representation in historical centers safety assessment: insights from Castelnuovo di Porto, Rome. Archeologia e Calcolatori, Supplemento 13, 217–231. https://doi.org/10.19282/acs.13.2025.16

Acknowledgments back to ToC

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.