# Ifc Agents Quality Checker > Use when an IFC file is schema-valid but you must judge whether it is actually useful, audit an IFC model for information completeness, score model quality before handover, or answer why a valid IFC file is empty in facility management, quantity take-off, or analysis software. Prevents confusing schema validity with information completeness, declaring a model "good" because it passed validation, auditing project-specific demands that belong to IDS, and shipping a model whose elements carry no properties, materials, classifications, quantities, or georeferencing. Covers a cross-skill model-quality audit across seven completeness dimensions (spatial containment, property sets, geometry representation, materials, classifications, quantities, georeferencing), a deterministic weighted scoring rubric, the validity-versus-completeness-versus-IDS three-tier model, and routing each gap to the owning skill, across IFC2x3, IFC4 and IFC4.3. Keywords: IFC quality check, IFC model audit, information completeness, model qua - Skill: `impertio-studio/ifc-agents-quality-checker` (Agent Skill, multi-file: 4 files) - Install (CLI): `npx skillmds@latest add impertio-studio/ifc-agents-quality-checker` - Raw SKILL.md: https://api.skillmd.com/api/skills/impertio-studio/ifc-agents-quality-checker/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - License: MIT - Author: Impertio-Studio (https://skillmd.com/u/impertio-studio) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/impertio-studio/ifc-agents-quality-checker --- # IFC Quality Checker (Orchestration) Drive a complete, scored quality audit over an IFC file. This is an ORCHESTRATION skill : it audits seven information-completeness dimensions, scores each with a deterministic rubric, produces one quality report, and routes every gap to the skill that holds the detailed fix. This skill answers one question : the file is valid, but is it any USE. A model can pass every buildingSMART validation stage and still be near-worthless downstream : walls with no properties, no materials, no classification, no quantities, sitting at the origin with no georeferencing. Validity is the floor, not the goal. This skill does NOT itself teach the fixes. It is the auditor ; the syntax, impl, and errors skills are the remediation. It does NOT run the schema-conformance pipeline either : that is `ifc-agents-file-validator`. ## Quick Reference ### The three-tier model : validity, completeness, requirements ALWAYS place every check in exactly one tier: | Tier | Question | Owner | |------|----------|-------| | 1. Schema validity | Does the file obey the IFC standard | `ifc-agents-file-validator` | | 2. Information completeness | Does the file carry the generic data any consumer needs | THIS skill | | 3. Project requirements | Does the file carry what a specific project demanded | IDS (out of package scope) | This skill owns tier 2 ONLY. NEVER audit tier-1 schema rules here : route them to `ifc-agents-file-validator`. NEVER audit tier-3 project-specific demands here : those are expressed in IDS, which this package does not cover. Tier 2 is the GENERIC completeness every downstream use (facility management, quantity take-off, energy and structural analysis, cost) needs regardless of project. ### Validity gate : audit quality only on a valid file ALWAYS confirm tier 1 first. Run `ifc-agents-file-validator` and require zero stage 1, 2, or 3 errors before this audit. A quality score on an invalid file is meaningless : a malformed file cannot be measured for coverage. If validation reports errors, STOP and route to `ifc-agents-file-validator`. ### The seven completeness dimensions | # | Dimension | Weight | What it measures | Route for gaps | |---|-----------|--------|------------------|----------------| | 1 | Spatial containment | 20 | every physical element placed in the spatial tree | `ifc-errors-spatial-structure`, `ifc-impl-spatial-decomposition` | | 2 | Property sets | 20 | elements carry the relevant `Pset_` properties | `ifc-errors-property-set-mistakes`, `ifc-impl-data-enrichment` | | 3 | Geometry representation | 15 | every element has a usable shape representation | `ifc-errors-geometry-issues`, `ifc-syntax-geometry-representations` | | 4 | Materials | 15 | elements carry material associations | `ifc-syntax-materials`, `ifc-impl-data-enrichment` | | 5 | Classifications | 10 | elements carry classification references | `ifc-syntax-classifications`, `ifc-impl-data-enrichment` | | 6 | Quantities | 10 | elements carry measured quantities for take-off | `ifc-syntax-quantities`, `ifc-impl-property-extraction` | | 7 | Georeferencing | 10 | the model is locatable in a real-world CRS | `ifc-syntax-georeferencing` | Weights sum to 100. They are FIXED : ALWAYS use these exact weights so two audits of the same file produce the same score. ### Scoring rubric (deterministic) For each dimension, compute `coverage = elements satisfying the check / elements in scope`, as a percentage. Then: - `coverage = 100%` : status COMPLETE. - `1% <= coverage <= 99%` : status PARTIAL. - `coverage = 0%` : status ABSENT. `dimension score = weight * coverage`. `overall score = sum of dimension scores`, 0 to 100. Grade bands, applied ALWAYS: | Overall score | Grade | |---------------|-------| | 90 to 100 | A | | 75 to 89 | B | | 50 to 74 | C | | 25 to 49 | D | | 0 to 24 | F | A dimension that is genuinely out of scope (for example precise georeferencing on a coordination-only model) is marked `not applicable` : drop it and renormalise the remaining weights to sum to 100. NEVER score a not-applicable dimension as 0. ## Decision Trees ### Is this a quality gap, a validity error, or a project requirement ``` The finding under review ... ├─ breaks an EXPRESS rule, a normative Gherkin rule, or the STEP syntax │ -> tier 1, schema validity. Route to ifc-agents-file-validator. ├─ is generic data any consumer needs, missing or thin (no Pset, no material, │ no class, no quantity, no georeferencing, an orphan element) │ -> tier 2. This skill. Score it under the matching dimension. └─ is a project-, client-, or nation-specific demand (a named Pset required by this contract, a specific LOD) -> tier 3. IDS territory. Out of this package's scope. Do NOT score it. ``` ### Which dimension does a symptom map to ``` Downstream symptom ... ├─ "element missing from the model tree / facility-management export" │ -> Dimension 1, spatial containment. ├─ "schedules and parameter views are empty" │ -> Dimension 2, property sets. ├─ "element has no shape / nothing draws in the viewer" │ -> Dimension 3, geometry representation. ├─ "material take-off / material schedule is empty" │ -> Dimension 4, materials. ├─ "cannot filter or cost by classification code" │ -> Dimension 5, classifications. ├─ "quantity take-off returns nothing" │ -> Dimension 6, quantities. └─ "model sits at the origin, will not align with survey or GIS" -> Dimension 7, georeferencing. ``` ### Georeferencing depth by version ``` What schema is the file ? ├─ IFC2x3 │ -> precise CRS georeferencing entities do not exist. Check IfcSite │ RefLatitude, RefLongitude, RefElevation only. Present = COMPLETE for │ this version ; absent = ABSENT. └─ IFC4 or IFC4.3 -> check IfcMapConversion plus IfcProjectedCRS (precise). Present = COMPLETE. Only IfcSite RefLatitude/RefLongitude present = PARTIAL (coarse only). Neither = ABSENT. ``` ## Patterns ### Pattern 1 : run the quality audit in order ALWAYS run the audit as an ordered pass: ``` 1. Validity gate : run ifc-agents-file-validator. Require zero tier-1 errors. If errors exist, STOP and route there. Do not score. 2. Determine the file schema (IFC2x3, IFC4, IFC4.3) and the declared MVD. Schema decides which entities the audit checks (Pattern 5, version notes). 3. Build the element scope : the set of physical element occurrences. In IFC2x3 and IFC4 these are IfcBuildingElement subtypes ; in IFC4.3 they are IfcBuiltElement subtypes (the entity was renamed and made non-abstract). 4. Audit dimensions 1 to 7 (Patterns 2 to 5), each producing a coverage %. 5. Score and grade (Pattern 6). Emit one report. ``` NEVER score before the validity gate passes. ### Pattern 2 : audit spatial containment (dimension 1) For every physical element occurrence, check it is contained in exactly one spatial level through `IfcRelContainedInSpatialStructure`, and that the spatial tree is complete from `IfcProject` down. - `coverage = contained elements / total physical elements`. - An element with zero containment links is an orphan : it does not count as covered. - ALSO confirm the tree itself : an `IfcProject`, at least one `IfcSite`, and an unbroken `IfcRelAggregates` chain. A broken tree caps this dimension at PARTIAL regardless of element coverage. Route gaps to `ifc-errors-spatial-structure` and `ifc-impl-spatial-decomposition`. ### Pattern 3 : audit property sets and quantities (dimensions 2 and 6) Properties and quantities share the same attachment machinery : both are `IfcPropertySetDefinition` subtypes attached through `IfcRelDefinesByProperties` (on occurrences) or the type object's `HasPropertySets` (on types). Audit them as two dimensions. Dimension 2, property sets: - For each element, check it carries the standardised common property set for its class : an `IfcPropertySet` named `Pset_Common` (for example `Pset_WallCommon` on `IfcWall`), resolving type-level and occurrence-level property sets and letting the occurrence win on a name collision. - `coverage = elements with their Pset_*Common / total elements`. - A custom property set whose `Name` uses the reserved `Pset_` prefix is a defect : flag it and route to `ifc-errors-property-set-mistakes`. It does NOT count as coverage. Dimension 6, quantities: - For each element, check it carries an `IfcElementQuantity` with the relevant measured quantities. IFC4 and IFC4.3 standardise the `Qto_` prefix (for example `Qto_WallBaseQuantities`) ; IFC2x3 used a `BaseQuantities`-style convention, so for IFC2x3 check for the presence of an `IfcElementQuantity`, NEVER for a `Qto_` name. - `coverage = elements with measured quantities / total elements`. Route property gaps to `ifc-errors-property-set-mistakes` and `ifc-impl-data-enrichment` ; quantity gaps to `ifc-syntax-quantities` and `ifc-impl-property-extraction`. ### Pattern 4 : audit materials and classifications (dimensions 4 and 5) Dimension 4, materials: - For each element, check a material association exists : an `IfcRelAssociatesMaterial` whose `RelatedObjects` includes the element (or its type) and whose `RelatingMaterial` is an `IfcMaterial`, `IfcMaterialLayerSet`, `IfcMaterialProfileSet`, `IfcMaterialConstituentSet`, or a usage of one. - `coverage = elements with a material association / total elements`. Dimension 5, classifications: - For each element, check an `IfcRelAssociatesClassification` exists whose `RelatingClassification` is an `IfcClassificationReference` (a code such as a Uniclass or OmniClass notation) or an `IfcClassification`. - `coverage = classified elements / total elements`. Route material gaps to `ifc-syntax-materials` and `ifc-impl-data-enrichment` ; classification gaps to `ifc-syntax-classifications` and `ifc-impl-data-enrichment`. ### Pattern 5 : audit geometry and georeferencing (dimensions 3 and 7) Dimension 3, geometry representation: - For each element, check it has an `IfcProductDefinitionShape` with at least one usable `IfcShapeRepresentation` (typically a `Body` representation) bound to a valid representation context. - `coverage = elements with a usable representation / total elements`. - A degenerate or context-less representation does NOT count : route it to `ifc-errors-geometry-issues`. Dimension 7, georeferencing : audit by version per the decision tree. - IFC4, IFC4.3 : COMPLETE when `IfcMapConversion` plus `IfcProjectedCRS` are present. PARTIAL when only `IfcSite` `RefLatitude` and `RefLongitude` are set. ABSENT when neither. - IFC2x3 : precise CRS entities do not exist. COMPLETE when `IfcSite` `RefLatitude`, `RefLongitude`, `RefElevation` are set ; ABSENT otherwise. Georeferencing is a single model-level dimension, not a per-element coverage : score it directly as COMPLETE (100%), PARTIAL (50%), or ABSENT (0%). Route gaps to `ifc-syntax-georeferencing`. ### Pattern 6 : produce the scored quality report Emit one report with a fixed structure. ALWAYS show every dimension, its weight, coverage, status, and weighted score, then the overall score and grade. ``` IFC Model Quality Report File schema : Declared MVD : Validity gate : PASSED (ifc-agents-file-validator, 0 errors) Dimension Weight Coverage Status Score 1 Spatial containment 20 __% __._ 2 Property sets 20 __% __._ 3 Geometry representation 15 __% __._ 4 Materials 15 __% __._ 5 Classifications 10 __% __._ 6 Quantities 10 __% __._ 7 Georeferencing 10 __% __._ Overall score : __ / 100 Grade : Gaps and routes : : -> ``` ALWAYS state the grade with the score. ALWAYS list, per gap, the owning skill so the reader can act. NEVER present a grade without the per-dimension breakdown : an opaque score hides which data is missing. ## Reference Links - `references/methods.md` : the seven dimensions in full, the check entities per dimension, the scoring formula, version notes, the anti-pattern-to-dimension map. - `references/examples.md` : worked audits and complete sample reports. - `references/anti-patterns.md` : auditing mistakes and why each one is wrong. ### Related skills - `ifc-agents-file-validator` : the tier-1 schema-conformance pipeline. ALWAYS run first. - `ifc-core-validation` : the conceptual validation model. - `ifc-impl-data-enrichment` : how to ADD the missing properties, materials, and classifications this audit reports. - `ifc-errors-spatial-structure`, `ifc-errors-property-set-mistakes`, `ifc-errors-geometry-issues` : the detailed fixes for each gap class. - `ifc-syntax-property-sets`, `ifc-syntax-quantities`, `ifc-syntax-materials`, `ifc-syntax-classifications`, `ifc-syntax-georeferencing` : the authoring syntax for each dimension. ### Verified sources The check entities (`IfcRelContainedInSpatialStructure`, `IfcPropertySet`, `IfcRelDefinesByProperties`, `IfcElementQuantity`, `IfcRelAssociatesMaterial`, `IfcRelAssociatesClassification`, `IfcClassificationReference`, `IfcMapConversion`, `IfcProjectedCRS`, `IfcSite`), the `Pset_` and `Qto_` conventions, and the version differences are verified 2026-05-20 against the buildingSMART IFC4.3, IFC4 ADD2 TC1, and IFC2x3 specifications recorded in `SOURCES.md`. The validity-pipeline boundary is sourced from the buildingSMART validation service documentation.