Frederic Bosche, University of Edinburgh
This ontology provides a semantic framework for representing roof condition inspection information, including roofs and roof pitches, inspections, orthophotos, and image-derived defect observations. It is designed to support structured documentation, querying, and interoperability within digital twin–based workflows for roof condition monitoring and maintenance, particularly in the context of existing and heritage buildings.
This ontology was developed with support from Historic Environment Scotland (HES) and the Engineering and Physical Sciences Research Council (EPSRC), and informed by collaboration with domain experts in heritage roof inspection and maintenance.
Represents a part–whole relationship where a roof consists of one or more pitches. Conceptually aligned with standard part–whole relations (e.g. BFO:has_part), without importing upper-level ontologies.
Relationship between a damage presence and the corresponding inspection observation.
Relationship between classified damage instances forming a composite classified damage.
Relationship between a damage and the product it affects.
Relationship between an Image and one or more Damage Observation Image Locations recorded within that image. This property is the inverse of has Image and enables queries from an image to the damage observation locations it contains.
Relationship between a damage image location and the corresponding image.
Links a Damage Inspection Observation to the corresponding Damage Observation Image Location where it is spatially located within visual documentation. This property is the inverse of locates and enables queries from inspection observations to their associated image locations.
Relationship between an inspection observation and the corresponding damage entity
Represents the relationship between a damage image location (e.g. a region on an orthophoto) and the damage inspection observation it refers to. This allows a detected damage observed during an inspection to be spatially located within visual documentation.
Relationship between a pitch and the roof it belongs to.
The confidence associated with an observation or assessment of a damage.
Specifies how inspection data were acquired, describing the data acquisition method used during an inspection (e.g. UAV-based photogrammetry, ground-based visual inspection, handheld photography, or mixed approaches). This property supports interpretation of inspection outcomes by making data provenance explicit.
Specifies the type of analysis applied to inspection data, such as AI-assisted image analysis, manual expert assessment, or hybrid approaches. This property clarifies how inspection findings and defect classifications were produced, and helps to make potential limitations of the inspection results explicit.
Describes the environmental conditions surrounding the building or present at the time of inspection that may influence moisture behaviour, surface visibility, and deterioration processes. Where more detailed environmental information is required, this property may be aligned with external weather or climate ontologies (e.g., https://bimerr.iot.linkeddata.es/def/weather/) to enable richer and time-specific representations.
Characterises the degree to which a pitch is exposed to weathering forces (e.g., sheltered or exposed). Exposure level influences the likelihood of wind-driven rain penetration, accelerated weathering of materials, and deterioration at junctions, but does not alone determine the presence or severity of defects.
Represents the assessed condition rating of a building element (e.g., roof or roof pitch), derived from visual inspection and used to indicate the severity of deterioration and the urgency of maintenance or repair. The value typically follows standardised building survey rating systems, such as the RICS Condition Ratings (1–3, traffic light system) or equivalent condition indices (e.g., numerical scales indicating maintenance, restoration, or replacement needs).
This data property specifies the type of defect identified for a Classified Damage during roof inspection. The defect types are expressed as descriptive values rather than modelled as individuals. They reflect inspection outcomes and expert interpretation. Typical defect types include: Slate Biological Growth (subclass of Classified Damage): – algae: thin biological growth typically associated with surface moisture and damp environmental conditions; – lichen: slow-growing biological organisms indicating long-term environmental exposure; – moss: thicker biological growth that retains moisture and may contribute to accelerated material deterioration. Slate Structural Defect (subclass of Classified Damage): – broken slate: cracked or fractured slate that may allow water penetration; – displaced slate: slate that has moved from its original position, potentially compromising weather tightness; – missing slate: complete absence of a slate, directly exposing underlying roof layers. The listed defect types are illustrative and not intended to form an exhaustive taxonomy.
Represents the observed or inferred repair status of a damage instance relative to the latest available inspection results, and where applicable, comparisons across multiple inspections. The status reflects the current observation-based interpretation and does not necessarily indicate the existence of an explicit repair record. Typical values include: - "active": The damage is explicitly detected and confirmed to be present in the latest inspection. - "not_observed": The damage is not detected in the latest inspection. This does not imply that the damage has been repaired, as the absence may be due to occlusion, limited visibility, data quality issues, or detection uncertainty. - "likely_repaired": Based on comparisons across multiple inspections, there is strong observational evidence suggesting that the damage may have been repaired; however, no explicit repair record or confirmation is available. - "confirmed_repaired": The damage is considered repaired based on explicit confirmation, such as a repair record, maintenance documentation, or expert validation. This status indicates recorded confirmation rather than purely observation-based inference.
The resolution of the orthophoto, representing the size of each pixel in meters. For example, a value of "0.005" means each pixel represents 5mm by 5mm.
The 3D spatial location of the damage instance in the real-world coordinate system.
A description of whether and how a damage is associated with a junction. This property is used to record junction-related context that is difficult to capture purely geometrically, such as “junction between slate and leadwork (material junction)” or “junction between roof and masonry (element junction)”. Junction information supports interpretation of likely failure mechanisms and potential water ingress pathways.
Indicates the junction category relevant to the damage (e.g., material junction or element junction). This supports consistent reporting and querying of junction-related failures.
Represents the facing direction (aspect) of a pitch (e.g., cardinal direction or azimuth). Orientation is pitch-specific and supports interpretation of differential moisture retention, biological growth, and weathering patterns observed during inspection, particularly where multiple pitches on the same roof exhibit different deterioration behaviours.
Pitch angle is a numerical value (expressed in degrees) representing the inclination of a roof surface. This property uses a decimal value to allow precise measurement. Indicative threshold ranges may be applied for roof characterisation: pitch angles below 10° typically indicate flat roofs; values between 10° and 45° represent low-pitched roofs; and angles greater than 45° indicate steeply pitched roofs. Variations in pitch angle influence drainage behaviour, exposure conditions, defect susceptibility, and inspection and maintenance considerations.
Specifies the relative position of a pitch within the overall roof configuration (e.g., upper pitch or lower pitch). Relative position is important for inspection interpretation, as lower pitches may receive runoff, debris, or moisture from higher pitches, and are often associated with junction-related issues and concealed water ingress pathways.
A description of the roof build-up (construction make-up), capturing the main roof-related elements and underlying materials relevant to condition assessment. This may include slates, ridge coverings, mortar fillets at wall abutments, lead flashings, wallhead/parapet gutters, chimney stacks, associated stonework/brickwork, and underlying layers such as masonry, lead, mortar, sarking/timber, or flat-roofing materials. This property is intended to record practical construction knowledge often missing from BIM models and to support interpretation of junction-related defects and water ingress mechanisms.
The 2D image location of the observation expressed in pixel coordinates within the associated image or orthophoto.
A Slate Structural Defect represents a physical damage potentially affecting the integrity or position of a roof slate, such as broken, displaced, or missing slate.
An Orthophoto is a geometrically corrected image produced from photogrammetric processing, providing a uniform scale representation of roof surfaces and serving as spatial evidence for damage documentation.
A Roof Inspection is a specialised inspection activity focusing on the condition assessment of roof elements, during which visual observations, images, and damage documentation are produced
A Roof Pitch is a subdivision of a roof used as a spatial unit for inspection and damage documentation.
Slate Biological Growth represents biologically induced surface conditions observed on roof slates, such as algae, moss, and lichen. These forms of growth are not necessarily defects in themselves, but are indicative of persistent moisture, local environmental conditions, and reduced drying potential. The presence and distribution of biological growth may signal emerging risks, particularly at junctions or areas prone to water retention, and therefore support interpretation of roof condition and prioritisation of further inspection.
A Damage Observation Image Location represents the spatial localisation of a detected or observed damage within an image or orthophoto.
A Damage Inspection Observation represents an observation made during an inspection indicating the presence of a potential damage.
DCMI Metadata Terms - other
The set of classes specified by the DCMI Type Vocabulary, used to categorize the nature or genre of the resource.
DCMI Type Vocabulary
The set of conceptual resources specified by the Dewey Decimal Classification.
DDC
The set of media types specified by the Internet Assigned Numbers Authority.
IMT
The set of conceptual resources specified by the Library of Congress Classification.
LCC
The set of labeled concepts specified by the Library of Congress Subject Headings.
LCSH
The set of labeled concepts specified by the Medical Subject Headings.
MeSH
The set of conceptual resources specified by the National Library of Medicine Classification.
NLM
The set of places specified by the Getty Thesaurus of Geographic Names.
TGN
The set of conceptual resources specified by the Universal Decimal Classification.
UDC
Instructional Method typically includes ways of presenting instructional materials or conducting instructional activities, patterns of learner-to-learner and learner-to-instructor interactions, and mechanisms by which group and individual levels of learning are measured. Instructional methods include all aspects of the instruction and learning processes from planning and implementation through evaluation and feedback.
A process, used to engender knowledge, attitudes and skills, that the described resource is designed to support.
Instructional Method
The statement may include a description of any changes successive custodians made to the resource.
A statement of any changes in ownership and custody of the resource since its creation that are significant for its authenticity, integrity, and interpretation.
Provenance
Recommended practice is to refer to the rights holder with a URI. If this is not possible or feasible, a literal value that identifies the rights holder may be provided.
A person or organization owning or managing rights over the resource.
Rights Holder
A resource that acts or has the power to act.
Agent
A group of agents.
Agent Class
A book, article, or other documentary resource.
Bibliographic Resource
The set of regions in space defined by their geographic coordinates according to the DCMI Box Encoding Scheme.
DCMI Box
A digital resource format.
File Format
A rate at which something recurs.
Frequency
The set of codes listed in ISO 3166-1 for the representation of names of countries.
ISO 3166
The three-letter alphabetic codes listed in ISO639-2 for the representation of names of languages.
ISO 639-2
The set of three-letter codes listed in ISO 639-3 for the representation of names of languages.
ISO 639-3
The extent or range of judicial, law enforcement, or other authority.
Jurisdiction
A legal document giving official permission to do something with a resource.
License Document
Written, spoken, sign, and computer languages are linguistic systems.
A system of signs, symbols, sounds, gestures, or rules used in communication.
Linguistic System
A spatial region or named place.
Location
A location, period of time, or jurisdiction.
Location, Period, or Jurisdiction
A file format or physical medium.
Media Type
A media type or extent.
Media Type or Extent
A method by which resources are added to a collection.
Method of Accrual
A process that is used to engender knowledge, attitudes, and skills.
Method of Instruction
The set of time intervals defined by their limits according to the DCMI Period Encoding Scheme.
DCMI Period
An interval of time that is named or defined by its start and end dates.
Period of Time
Examples include paper, canvas, or DVD.
A physical material or carrier.
Physical Medium
A material thing.
Physical Resource
The set of points in space defined by their geographic coordinates according to the DCMI Point Encoding Scheme.
DCMI Point
A plan or course of action by an authority, intended to influence and determine decisions, actions, and other matters.
Policy
Any changes in ownership and custody of a resource since its creation that are significant for its authenticity, integrity, and interpretation.
Provenance Statement
The set of tags, constructed according to RFC 1766, for the identification of languages.
RFC 1766
RFC 3066 has been obsoleted by RFC 4646.
The set of tags constructed according to RFC 3066 for the identification of languages.
RFC 3066
RFC 4646 obsoletes RFC 3066.
The set of tags constructed according to RFC 4646 for the identification of languages.
RFC 4646
RFC 5646 obsoletes RFC 4646.
The set of tags constructed according to RFC 5646 for the identification of languages.
RFC 5646
A statement about the intellectual property rights (IPR) held in or over a resource, a legal document giving official permission to do something with a resource, or a statement about access rights.
Rights Statement
Examples include a number of pages, a specification of length, width, and breadth, or a period in hours, minutes, and seconds.
A dimension or extent, or a time taken to play or execute.
Size or Duration
A reference point against which other things can be evaluated or compared.
Standard
The set of identifiers constructed according to the generic syntax for Uniform Resource Identifiers as specified by the Internet Engineering Task Force.
URI
The set of dates and times constructed according to the W3C Date and Time Formats Specification.
W3C-DTF
A summary of the resource.
Abstract
Access Rights may include information regarding access or restrictions based on privacy, security, or other policies.
Information about who access the resource or an indication of its security status.
Access Rights
Recommended practice is to use a value from the Collection Description Accrual Method Vocabulary [[DCMI-ACCRUALMETHOD](https://dublincore.org/groups/collections/accrual-method/)].
The method by which items are added to a collection.
Accrual Method
Recommended practice is to use a value from the Collection Description Frequency Vocabulary [[DCMI-COLLFREQ](https://dublincore.org/groups/collections/frequency/)].
The frequency with which items are added to a collection.
Accrual Periodicity
Recommended practice is to use a value from the Collection Description Accrual Policy Vocabulary [[DCMI-ACCRUALPOLICY](https://dublincore.org/groups/collections/accrual-policy/)].
The policy governing the addition of items to a collection.
Accrual Policy
The distinction between titles and alternative titles is application-specific.
An alternative name for the resource.
Alternative Title
Recommended practice is to use this property with non-literal values from a vocabulary of audience types.
A class of agents for whom the resource is intended or useful.
Audience
Recommended practice is to describe the date, date/time, or period of time as recommended for the property Date, of which this is a subproperty.
Date that the resource became or will become available.
Date Available
Recommended practice is to include sufficient bibliographic detail to identify the resource as unambiguously as possible.
A bibliographic reference for the resource.
Bibliographic Citation
An established standard to which the described resource conforms.
Conforms To
The guidelines for using names of persons or organizations as creators apply to contributors.
An entity responsible for making contributions to the resource.
Contributor
Spatial topic and spatial applicability may be a named place or a location specified by its geographic coordinates. Temporal topic may be a named period, date, or date range. A jurisdiction may be a named administrative entity or a geographic place to which the resource applies. Recommended practice is to use a controlled vocabulary such as the Getty Thesaurus of Geographic Names [[TGN](https://www.getty.edu/research/tools/vocabulary/tgn/index.html)]. Where appropriate, named places or time periods may be used in preference to numeric identifiers such as sets of coordinates or date ranges. Because coverage is so broadly defined, it is preferable to use the more specific subproperties Temporal Coverage and Spatial Coverage.
The spatial or temporal topic of the resource, spatial applicability of the resource, or jurisdiction under which the resource is relevant.
Coverage
Date of creation of the resource.
Date Created
Recommended practice is to identify the creator with a URI. If this is not possible or feasible, a literal value that identifies the creator may be provided.
An entity responsible for making the resource.
Creator
Date may be used to express temporal information at any level of granularity. Recommended practice is to express the date, date/time, or period of time according to ISO 8601-1 [[ISO 8601-1](https://www.iso.org/iso-8601-date-and-time-format.html)] or a published profile of the ISO standard, such as the W3C Note on Date and Time Formats [[W3CDTF](https://www.w3.org/TR/NOTE-datetime)] or the Extended Date/Time Format Specification [[EDTF](http://www.loc.gov/standards/datetime/)]. If the full date is unknown, month and year (YYYY-MM) or just year (YYYY) may be used. Date ranges may be specified using ISO 8601 period of time specification in which start and end dates are separated by a '/' (slash) character. Either the start or end date may be missing.
A point or period of time associated with an event in the lifecycle of the resource.
Date
Recommended practice is to describe the date, date/time, or period of time as recommended for the property Date, of which this is a subproperty. Examples of resources to which a date of acceptance may be relevant are a thesis (accepted by a university department) or an article (accepted by a journal).
Date of acceptance of the resource.
Date Accepted
Typically a year. Recommended practice is to describe the date, date/time, or period of time as recommended for the property Date, of which this is a subproperty.
Date of copyright of the resource.
Date Copyrighted
Recommended practice is to describe the date, date/time, or period of time as recommended for the property Date, of which this is a subproperty. Examples of resources to which a 'Date Submitted' may be relevant include a thesis (submitted to a university department) or an article (submitted to a journal).
Date of submission of the resource.
Date Submitted
Description may include but is not limited to: an abstract, a table of contents, a graphical representation, or a free-text account of the resource.
An account of the resource.
Description
A class of agents, defined in terms of progression through an educational or training context, for which the described resource is intended.
Audience Education Level
Recommended practice is to specify the file size in megabytes and duration in ISO 8601 format.
The size or duration of the resource.
Extent
Recommended practice is to use a controlled vocabulary where available. For example, for file formats one could use the list of Internet Media Types [[MIME](https://www.iana.org/assignments/media-types/media-types.xhtml)]. Examples of dimensions include size and duration.
The file format, physical medium, or dimensions of the resource.
Format
This property is intended to be used with non-literal values. This property is an inverse property of Is Format Of.
A related resource that is substantially the same as the pre-existing described resource, but in another format.
Has Format
This property is intended to be used with non-literal values. This property is an inverse property of Is Part Of.
A related resource that is included either physically or logically in the described resource.
Has Part
Changes in version imply substantive changes in content rather than differences in format. This property is intended to be used with non-literal values. This property is an inverse property of Is Version Of.
A related resource that is a version, edition, or adaptation of the described resource.
Has Version
Recommended practice is to identify the resource by means of a string conforming to an identification system. Examples include International Standard Book Number (ISBN), Digital Object Identifier (DOI), and Uniform Resource Name (URN). Persistent identifiers should be provided as HTTP URIs.
An unambiguous reference to the resource within a given context.
Identifier
This property is intended to be used with non-literal values. This property is an inverse property of Has Format.
A pre-existing related resource that is substantially the same as the described resource, but in another format.
Is Format Of
This property is intended to be used with non-literal values. This property is an inverse property of Has Part.
A related resource in which the described resource is physically or logically included.
Is Part Of
This property is intended to be used with non-literal values. This property is an inverse property of References.
A related resource that references, cites, or otherwise points to the described resource.
Is Referenced By
This property is intended to be used with non-literal values. This property is an inverse property of Replaces.
A related resource that supplants, displaces, or supersedes the described resource.
Is Replaced By
This property is intended to be used with non-literal values. This property is an inverse property of Requires.
A related resource that requires the described resource to support its function, delivery, or coherence.
Is Required By
Changes in version imply substantive changes in content rather than differences in format. This property is intended to be used with non-literal values. This property is an inverse property of Has Version.
A related resource of which the described resource is a version, edition, or adaptation.
Is Version Of
Date of formal issuance of the resource.
Date Issued
Recommended practice is to use either a non-literal value representing a language from a controlled vocabulary such as ISO 639-2 or ISO 639-3, or a literal value consisting of an IETF Best Current Practice 47 [[IETF-BCP47](https://tools.ietf.org/html/bcp47)] language tag.
A language of the resource.
Language
Recommended practice is to identify the license document with a URI. If this is not possible or feasible, a literal value that identifies the license may be provided.
A legal document giving official permission to do something with the resource.
License
In an educational context, a mediator might be a parent, teacher, teaching assistant, or care-giver.
An entity that mediates access to the resource.
Mediator
The material or physical carrier of the resource.
Medium
Date on which the resource was changed.
Date Modified
An entity responsible for making the resource available.
Publisher
This property is intended to be used with non-literal values. This property is an inverse property of Is Referenced By.
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
References
Recommended practice is to identify the related resource by means of a URI. If this is not possible or feasible, a string conforming to a formal identification system may be provided.
A related resource.
Relation
This property is intended to be used with non-literal values. This property is an inverse property of Is Replaced By.
A related resource that is supplanted, displaced, or superseded by the described resource.
Replaces
This property is intended to be used with non-literal values. This property is an inverse property of Is Required By.
A related resource that is required by the described resource to support its function, delivery, or coherence.
Requires
Typically, rights information includes a statement about various property rights associated with the resource, including intellectual property rights. Recommended practice is to refer to a rights statement with a URI. If this is not possible or feasible, a literal value (name, label, or short text) may be provided.
Information about rights held in and over the resource.
Rights
This property is intended to be used with non-literal values. The described resource may be derived from the related resource in whole or in part. Best practice is to identify the related resource by means of a URI or a string conforming to a formal identification system.
A related resource from which the described resource is derived.
Source
Spatial characteristics of the resource.
Spatial Coverage
Recommended practice is to refer to the subject with a URI. If this is not possible or feasible, a literal value that identifies the subject may be provided. Both should preferably refer to a subject in a controlled vocabulary.
A topic of the resource.
Subject
A list of subunits of the resource.
Table Of Contents
Temporal characteristics of the resource.
Temporal Coverage
A name given to the resource.
Title
Recommended practice is to use a controlled vocabulary such as the DCMI Type Vocabulary [[DCMI-TYPE](http://dublincore.org/documents/dcmi-type-vocabulary/)]. To describe the file format, physical medium, or dimensions of the resource, use the property Format.
The nature or genre of the resource.
Type
Date (often a range) of validity of a resource.
Date Valid