decisions: - id: DEC-001 topic: upper_ontology decision: defer status: accepted candidates_considered: [BFO-2020, DOLCE, GIST] rationale: > The ontology is a standalone application vocabulary for AI grounding and cataloguing over a single research corpus. No cross-domain reasoning requirement exists. Continuant/occurrent and role/realizable distinctions are applied informally (Role classes, Event/Activity classes) without importing BFO axioms. Revisit if the property-intelligence platform needs to integrate with BFO- or GIST-based enterprise ontologies. evidence: [] affects: [architecture] date: "2026-09-14" - id: DEC-002 topic: import_strategy decision: reuse_by_iri_without_import status: accepted rationale: > PROV-O (prov:Agent, prov:Activity, prov:Entity, prov:wasDerivedFrom), SKOS, Dublin Core Terms and XSD are referenced by IRI. No owl:imports is declared, so the reasoning environment stays small and version drift is avoided. schema.org, W3C ORG and GeoSPARQL are recorded as candidate mappings only (skos:closeMatch / rdfs:seeAlso) because their definitions were not compared against pinned versions during this build. evidence: [] affects: [architecture, mappings] date: "2026-09-14" - id: DEC-003 topic: role_modelling decision: role_participation_pattern status: accepted rationale: > The sources repeatedly describe the same party in different capacities: an owner can be an operator, an operator can be the owner's tenant and the resident's landlord, an owner-occupier can be a provider. Owner, Investor, Operator, Resident, PropertyManager, Lender, Insurer, Developer, Regulator are therefore modelled as named individuals of pbo:Role (also SKOS concepts in the RoleScheme) realised through a pbo:Participation node (party, role, agreement/property/activity context, optional validity dates), not as subclasses of Person/Organisation. Application-level convenience properties (pbo:ownedBy, pbo:managedBy) are retained as shortcuts and declared as such. evidence: [EV-050, EV-062, EV-071, EV-084] affects: [TERM-Participation, TERM-Role, CQ-003] date: "2026-09-14" - id: DEC-004 topic: event_relation_pattern decision: first_class_agreement_and_authorisation_nodes status: accepted rationale: > Agreements (leases, head leases, subleases, management agreements) and authorisations (planning approvals, registrations, licences, accreditations) carry parties, jurisdiction, term, rent, thresholds, validity and source. They are modelled as first-class classes rather than binary properties so that CQ-001 to CQ-003 can be answered without RDF reification. Simple binary relations (pbo:locatedIn, pbo:governedBy) stay binary. evidence: [EV-060, EV-061, EV-090] affects: [TERM-Agreement, TERM-Authorisation, CQ-001, CQ-003] date: "2026-09-14" - id: DEC-005 topic: taxonomy_vs_class_hierarchy decision: skos_for_classification_values status: accepted rationale: > Investment strategies, ownership structures, operating models, accommodation types, lease types, tenant configurations, agency business models, risk categories, metrics, building classifications, tax classifications, authorisation types, tenant segments and data-access tiers are classification values whose sources disagree on boundaries and which are combined freely (a rooming house can be operated under a master lease by a company). They are SKOS concepts in named schemes, bound to OWL classes through classification object properties. Each concept is also typed as an individual of its kind class (pbo:OperatingModel, pbo:InvestmentStrategy, ...) so that object properties such as strategyUsesOperatingModel have a proper OWL range (PAT-003). OWL subclassing is reserved for structural type semantics (Agreement subtypes, Authorisation subtypes, PropertyAsset subtypes, InformationArtefact subtypes) where every instance genuinely is-a parent. evidence: [EV-020, EV-021, EV-040, EV-075] affects: [taxonomy.ttl, ontology.ttl] date: "2026-09-14" - id: DEC-006 topic: measurement_pattern decision: metric_observation_node status: accepted rationale: > Financial figures in the corpus are always qualified by basis, assumptions, publisher and date, and the same metric (gross yield) is reported with conflicting values. A pbo:MetricValue node (metric concept, numeric value, unit, basis note, scenario or property it describes, source) is used instead of bare datatype properties so that CQ-004 and CQ-011 can be answered and conflicts preserved. Scenario assumptions reuse the same node type with pbo:assumes; results use pbo:yields. evidence: [EV-100, EV-101, EV-110] affects: [TERM-MetricValue, TERM-FinancialScenario, CQ-004, CQ-011] date: "2026-09-14" - id: DEC-007 topic: regulatory_threshold_pattern decision: threshold_node_on_regime status: accepted rationale: > Occupancy thresholds (four or more residents, 1-3 rooms with bond, nine bedrooms / 12 persons / 300 m2, five lets / 300 m2) are the single most decision-critical facts in the corpus. They are modelled as pbo:OccupancyThreshold nodes attached to a pbo:RegulatoryRegime with thresholdKind (SKOS), comparison, value, unit and effect, rather than as literal properties, so that jurisdictions with multiple thresholds and exemptions can be represented and queried (CQ-002). evidence: [EV-091, EV-092, EV-093, EV-094] affects: [TERM-OccupancyThreshold, CQ-002] date: "2026-09-14" - id: DEC-008 topic: source_conflict_resolution decision: preserve_conflicts_as_disputed status: accepted rationale: > Yield claims (5%, 8%, 8-12%, 10-12%+, 10-15%, 15-18%), coliving break-even (6-12 vs 12-18 months), rooming-house definitions (four or more unrelated tenants vs five studios vs six bedrooms) and vacancy behaviour (lower vs higher) conflict across sources. No source is authoritative over the others on these points, so the conflicts are preserved as evidence records with distinct MetricValue instances and listed in model.yaml unresolved_issues. Government/regulator sources (ATO, RTA, Business Queensland) outrank commercial and forum sources only on the legal/tax matters they address. evidence: [EV-110, EV-111, EV-112, EV-120] affects: [CQ-011, unresolved_issues] date: "2026-09-14" - id: DEC-009 topic: domain_range_policy decision: conservative_domain_range status: accepted rationale: > rdfs:domain / rdfs:range are asserted only where the inference is safe for every use in the corpus. Properties that legitimately apply to several unrelated classes (pbo:hasRisk applies to strategies, operating models, projects and agreements; pbo:hasMetricValue applies to scenarios, properties and market claims) are given a general domain (pbo:Entity or owl:Thing left unstated) and constrained per target class in SHACL. Warnings from the validator about omitted domain/range are intentional and documented here. evidence: [] affects: [ontology.ttl, shapes.ttl] date: "2026-09-14" - id: DEC-010 topic: naming_iri_policy decision: camelcase_hash_namespace status: accepted rationale: > Base IRI https://ontology.property.local/pbo# with UpperCamelCase classes, lowerCamelCase properties, and SKOS concepts under scheme-prefixed local names (e.g. pbo:OperatingModel_MasterLease). Individuals used as fixtures use the prefix "ex" within the same namespace but are only in instances.ttl. The .local host signals that the namespace is not yet published; a persistent namespace should be chosen before any "released" version. evidence: [] affects: [all artifacts] date: "2026-09-14" - id: DEC-011 topic: temporal_validity decision: validity_dates_on_authorisations_agreements_and_rules status: accepted rationale: > Tax rules change on 1 July 2027 with a 12 May 2026 grandfathering cut-off; Victorian smoke-alarm and rent-increase rules changed on 25 November 2025; the short-stay levy began 1 January 2025; foreign-buyer restrictions run 1 April 2025 to 31 March 2027. pbo:effectiveFrom / pbo:effectiveUntil / pbo:cutoffDate datatype properties are placed on pbo:RegulatoryRule, pbo:Authorisation and pbo:Agreement. OWL-Time intervals are not imported; xsd:date literals are sufficient for CQ-012. evidence: [EV-130, EV-131, EV-132] affects: [TERM-RegulatoryRule, CQ-012] date: "2026-09-14" - id: DEC-012 topic: source_authority_ranking decision: authority_by_source_type_not_polish status: accepted rationale: > Authority levels in sources.yaml follow the category syntheses' own evidence notes: government/regulator pages (ATO, RTA, Business Queensland) are authoritative; the academic paper (Chartres 2017) is primary research; the two deep-research reports are secondary syntheses with dated citations; industry articles, vendor pages, investment offers and forum threads are illustrative or secondary. Promotional yield claims are never accepted as domain truth; they are catalogued as claims. evidence: [] affects: [sources.yaml, evidence.jsonl] date: "2026-09-14" - id: DEC-013 topic: data_source_modelling decision: include_data_sources_as_information_resources status: accepted rationale: > The data-sources report is part of the corpus and the intended platform needs to know which dataset supplies which attribute. pbo:DataSource and pbo:Dataset are modelled as information resources (subclasses of pbo:InformationArtefact) with publisher, access tier (SKOS), refresh cadence, licence and pbo:suppliesAttribute links to pbo:PropertyAttribute concepts. Dataset internals (fields, geometries) are out of scope. evidence: [EV-140, EV-141] affects: [TERM-DataSource, CQ-009] date: "2026-09-14" - id: DEC-014 topic: jurisdiction_modelling decision: jurisdiction_individuals_with_containment status: accepted rationale: > Jurisdictions (Australia, Queensland, Victoria, NSW, WA, SA, Brisbane LGA, Logan LGA, Greater Melbourne) are named individuals of pbo:Jurisdiction in instances.ttl with pbo:withinJurisdiction containment, because the corpus names them as particulars and CQs filter by them. Foreign jurisdictions (Spain, Canada, Sweden, UK, US) exist only as source-context individuals. evidence: [EV-090, EV-095] affects: [TERM-Jurisdiction, instances.ttl] date: "2026-09-14" - id: DEC-015 topic: shacl_scope decision: shacl_for_record_completeness_only status: accepted rationale: > SHACL shapes require completeness for records the platform will store (FinancialScenario must declare its assumptions; Authorisation must have a jurisdiction, type and status; Agreement must have at least two participations; MetricValue must have a metric and a numeric value; OccupancyThreshold must have kind, comparator and value). Shapes do not encode domain truths such as "every rooming house has four or more residents", because sources disagree and exemptions exist. evidence: [] affects: [shapes.ttl] date: "2026-09-14" - id: DEC-016 topic: synthesis_documents_as_sources decision: synthesis_documents_are_secondary_sources status: accepted rationale: > The seven category summaries, seven combined source references and two deep-research reports were compiled on 14 September 2026 from the raw sources plus (for the reports) external citations not present in the corpus. They are registered as secondary sources with their own IDs. Claims that appear only in a synthesis (e.g. Queensland residential-service accreditation levels, Victorian Clause 52.23 limits, negative-gearing reform dates) are recorded with support "explicit" against the synthesis but flagged in notes as not independently verifiable from the raw corpus. evidence: [] affects: [sources.yaml, evidence.jsonl] date: "2026-09-14"