# Ifc Impl Cobie

> Use when producing, reading, or extracting COBie facility-management handover data from an IFC model: mapping COBie worksheets to IFC entities, deciding which records belong in COBie scope, choosing between the IFC STEP exchange and the spreadsheet form, or extracting a COBie subset from a full design model. Prevents treating COBie as a geometry format, inventing IFC entity names for COBie records, mapping a Component to a type instead of an occurrence, and exporting parametric geometry into an FM handover. Covers COBie as the Basic FM Handover MVD subset, the worksheet to IFC entity map, the IFC2x3 and IFC4 bindings, and the STEP versus spreadsheet exchange. Keywords: COBie, FM handover, facility management handover, Basic FM Handover MVD, asset management data, IfcSpace, IfcZone, IfcSystem, IfcTask, IfcDocumentReference, IfcConstructionResource, COBie spreadsheet, COBie worksheet, component versus type, asset register from IFC, handover data, how do I export COBie, what is COBie, COBie data missing, non-gra

- Skill: `impertio-studio/ifc-impl-cobie` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add impertio-studio/ifc-impl-cobie`
- Raw SKILL.md: https://api.skillmd.com/api/skills/impertio-studio/ifc-impl-cobie/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- License: MIT
- Author: Impertio-Studio (https://skillmd.com/u/impertio-studio)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/impertio-studio/ifc-impl-cobie

---


# IFC and COBie

COBie (Construction-Operations Building Information Exchange) is the
facility-management handover dataset: the non-graphic data an owner needs
to populate a maintenance and asset-management system. In IFC terms COBie
is a MODEL VIEW DEFINITION SUBSET, realised as the Basic FM Handover View.
It captures spaces, zones, components, types, systems, spares, resources,
jobs, documents, and attributes. It is NOT a geometry format.

This skill covers the COBie worksheet to IFC entity map, the IFC2x3 and
IFC4 bindings, the STEP versus spreadsheet exchange forms, and extracting a
COBie subset from a full model.

Verified against the buildingSMART MVD database and the IFC 4.3.2
specification (ISO 16739-1:2024). The Basic FM Handover View is verified as
an IFC2x3 TC1 MVD with status Final. COBie applies to IFC2x3, IFC4, IFC4.3.

## Quick Reference

### What COBie is and is not

| COBie IS | COBie is NOT |
|----------|--------------|
| A subset of IFC: non-graphic FM handover data | A separate file format competing with IFC |
| Spaces, equipment, types, systems, jobs, documents | A geometry or visualisation format |
| Exchangeable as IFC STEP, ifcXML, or a spreadsheet | A replacement for the design model |
| The Basic FM Handover MVD applied at handover | A live maintenance database |

COBie data ALWAYS lives in standard IFC entities. There is no `IfcCobie*`
entity. NEVER invent one.

### The COBie worksheet to IFC entity map

| COBie worksheet | IFC entity | Version note |
|-----------------|------------|--------------|
| Contact | `IfcActor`, with `IfcPerson` / `IfcOrganization` / `IfcPersonAndOrganization` | all |
| Facility | `IfcBuilding` within `IfcProject` and `IfcSite` | `IfcFacility` exists in IFC4.3; COBie uses `IfcBuilding` |
| Floor | `IfcBuildingStorey` | all |
| Space | `IfcSpace` | all |
| Zone | `IfcZone` | all |
| Type | `IfcElementType` subtypes (`IfcFurnitureType`, `IfcDistributionElementType`, ...) | all |
| Component | `IfcElement` occurrences | all |
| System | `IfcSystem` | all |
| Assembly | `IfcRelAggregates` or `IfcRelNests` | all |
| Connection | `IfcRelConnectsElements` and the `IfcRelConnects` family | all |
| Spare | `IfcConstructionProductResource` | all |
| Resource | `IfcConstructionResource` subtypes | all |
| Job | `IfcTask` | `TaskTime`, `PredefinedType` are IFC4 additions |
| Document | `IfcDocumentInformation` and `IfcDocumentReference` | all |
| Attribute | `IfcPropertySet` and `IfcProperty` | all |
| Coordinate | `ObjectPlacement` on the spatial or component entity | all |

Full attribute signatures and the relationships that wire these together
are in `references/methods.md`.

### COBie versions and IFC bindings

| COBie release | IFC binding | MVD |
|---------------|-------------|-----|
| COBie 2.26 | IFC2x3 TC1 | Basic FM Handover View (status Final) |
| COBie 2.4 | IFC4 | FM Handover, produced by the buildingSMART MVD support group |

The buildingSMART MVD database enumerates the Basic FM Handover View on
IFC2x3 TC1. buildingSMART runs the COBie Certified Professional programme,
aligned with ISO 19650. ALWAYS bind a COBie export to the schema named in
`FILE_SCHEMA`; NEVER mix IFC2x3 and IFC4 entity sets in one file.

### The two exchange forms

- IFC STEP physical file or ifcXML: the full-fidelity exchange, used for
  large projects and when the COBie data must round-trip with the model.
- The COBie spreadsheet (one tab per worksheet): the lightweight exchange,
  used for small projects and human review. National codes of practice
  govern the spreadsheet layout (for example BS 1192-4 in the UK).

Both forms carry the SAME data. The spreadsheet is a projection of the IFC
entities, NOT a different dataset.

## Decision Trees

### Is this data in COBie scope?

```
What kind of data is it?
|
+- Managed physical asset (equipment, fixture, furniture) that the
|  owner maintains
|    -> in scope. Component (IfcElement) + Type (IfcElementType).
|
+- Space, floor, zone, or facility the asset sits in
|    -> in scope. Spatial backbone.
|
+- Maintenance job, spare part, resource, document, contact
|    -> in scope. Job / Spare / Resource / Document / Contact.
|
+- Detailed parametric geometry, structural analysis, fabrication
|  detail, construction sequencing geometry
     -> NOT in scope. COBie carries non-graphic FM data only.
```

A wall's exact swept-solid profile is NEVER COBie data. The wall as a
maintainable Component, with its Type and attributes, IS.

### Which IFC entity for a COBie record?

```
Which COBie worksheet is the record on?
|
+- Component  -> an IfcElement OCCURRENCE (the placed instance)
+- Type       -> an IfcElementType (shared definition)
+- Space      -> IfcSpace ; Floor -> IfcBuildingStorey
+- Zone       -> IfcZone, members assigned by IfcRelAssignsToGroup
+- System     -> IfcSystem, members assigned by IfcRelAssignsToGroup
+- Job        -> IfcTask, operating on products via IfcRelAssignsToProcess
+- Document   -> IfcDocumentInformation + IfcDocumentReference,
|                associated by IfcRelAssociatesDocument
+- Attribute  -> an IfcProperty inside an IfcPropertySet
+- Spare      -> IfcConstructionProductResource
+- Resource   -> an IfcConstructionResource subtype
```

NEVER map a Component to a type object. A Component is a placed occurrence;
its shared data lives on the linked Type. See the occurrence-versus-type
split below.

### STEP or ifcXML or spreadsheet?

```
What is the consumer?
|
+- Another IFC-aware tool, or the data must round-trip with the
|  model
|    -> IFC STEP physical file (.ifc) or ifcXML (.ifcXML).
|
+- A human reviewer, a small project, or a CAFM import that
|  expects tabular input
     -> the COBie spreadsheet (one tab per worksheet).
```

ALWAYS keep the IFC file authoritative. The spreadsheet is generated FROM
the IFC entities; edits made only in the spreadsheet drift from the model.

### Component or Type for shared data?

```
Does the data value vary per placed instance?
|
+- Yes (asset tag, serial number, install date, barcode,
|  warranty start)
|    -> the Component occurrence (IfcElement).
|
+- No (manufacturer, model number, nominal length, expected life,
   replacement cost)
     -> the Type (IfcElementType), shared by every Component of
        that type.
```

This mirrors the COBie split: the Type worksheet holds the catalogue data,
the Component worksheet holds the per-instance data. See
`ifc-impl-data-enrichment` for the attachment mechanics.

## Patterns

Every snippet uses STEP physical file syntax. `$` marks an unset optional
attribute. Full verified signatures are in `references/methods.md`;
complete instances are in `references/examples.md`.

### Pattern: the spatial backbone

COBie Facility, Floor, and Space are the IFC spatial structure: an
`IfcBuilding` decomposed into `IfcBuildingStorey`, decomposed into
`IfcSpace`, all wired by `IfcRelAggregates`.

```step
#10=IFCBUILDING('0FacilityGuid0000000001',#5,'Main Building',$,$,
  $,$,$,.ELEMENT.,$,$,$);
#11=IFCBUILDINGSTOREY('0FloorGuid000000000001',#5,'Level 1',$,$,
  #82,$,$,.ELEMENT.,0.);
#12=IFCSPACE('0SpaceGuid000000000001',#5,'A-101',$,$,#83,$,'Office',
  .ELEMENT.,$,$);
```

Every COBie Space ALWAYS belongs to exactly one Floor through
`IfcRelAggregates`. See `ifc-impl-spatial-decomposition`.

### Pattern: Zone grouping

A COBie Zone groups spaces. `IfcZone` is a subtype of `IfcSystem`; its
members are assigned by `IfcRelAssignsToGroup`.

```step
#20=IFCZONE('0ZoneGuid0000000000001',#5,'Fire Compartment 1',$,$,$);
#21=IFCRELASSIGNSTOGROUP('0ZoneAssignGuid000001',#5,$,$,
  (#12,#13),$,#20);
```

`IfcRelAssignsToGroup` carries the members in `RelatedObjects` and the zone
in `RelatingGroup`. A zone member is ALWAYS an `IfcSpace`, `IfcZone`, or
`IfcSpatialZone` per the `IfcZone` `WHERE` rule.

### Pattern: Component and Type

A COBie Component is an `IfcElement` occurrence; its COBie Type is an
`IfcElementType`. The two are linked by `IfcRelDefinesByType`.

```step
#30=IFCFURNITURETYPE('0TypeGuid0000000000001',#5,'Desk-1200',$,$,
  $,$,$,$,.NOTDEFINED.,.USERDEFINED.);
#31=IFCFURNITURE('0CompGuid0000000000001',#5,'Desk A-101-01',$,$,
  #84,#90,'ASSET-0001',$);
#32=IFCRELDEFINESBYTYPE('0TypeRelGuid000000001',#5,$,$,(#31),#30);
```

Catalogue data (manufacturer, model) goes on the Type; per-instance data
(the `Tag` asset id) goes on the Component. NEVER place an asset tag on the
shared Type.

### Pattern: System grouping

A COBie System groups the components that work together (an HVAC system, a
lighting circuit). `IfcSystem` members are assigned by
`IfcRelAssignsToGroup`.

```step
#40=IFCSYSTEM('0SystemGuid000000001',#5,'AHU-1 Supply Air',$,$);
#41=IFCRELASSIGNSTOGROUP('0SysAssignGuid00001',#5,$,$,
  (#31,#33,#34),$,#40);
```

The same component is allowed in several systems through separate
`IfcRelAssignsToGroup` instances.

### Pattern: Job as an IfcTask

A COBie Job is maintenance work. It is an `IfcTask`, linked to the
component it acts on by `IfcRelAssignsToProcess`.

```step
#50=IFCTASK('0JobGuid00000000000001',#5,'Filter replacement',$,$,
  $,$,'NOTSTARTED','Scheduled',.F.,$,$,.MAINTENANCE.);
#51=IFCRELASSIGNSTOPROCESS('0JobRelGuid0000000001',#5,$,$,
  (#31),$,#50,$);
```

`PredefinedType` (`.MAINTENANCE.`) and `TaskTime` are IFC4 additions. On an
IFC2x3 file `IfcTask` carries a `TaskId` instead and has no `TaskTime`.

### Pattern: Document association

A COBie Document is an `IfcDocumentInformation` plus an
`IfcDocumentReference`, associated to objects by `IfcRelAssociatesDocument`.

```step
#60=IFCDOCUMENTINFORMATION('OM-001','O+M Manual AHU-1',$,$,$,$,$,
  $,$,$,$,$,$,$,$,$,$);
#61=IFCDOCUMENTREFERENCE('https://docs.example/om-001.pdf',$,
  $,$,#60);
#62=IFCRELASSOCIATESDOCUMENT('0DocRelGuid0000000001',#5,$,$,
  (#31),#61);
```

`IfcDocumentReference` carries either a `Name` OR a `ReferencedDocument`,
never both (the `WR1` constraint). Here `ReferencedDocument` is set, so
`Name` is `$`; the human-readable title lives on the
`IfcDocumentInformation`. See `ifc-syntax-classifications` for the related
external-reference pattern.

### Pattern: extracting a COBie subset

COBie export is a SUBSET extraction from a full model. ALWAYS:

1. Keep the spatial backbone (`IfcProject`, `IfcSite`, `IfcBuilding`,
   `IfcBuildingStorey`, `IfcSpace`).
2. Keep the maintainable components and their types; drop elements with no
   FM relevance.
3. Keep the FM property sets (`Pset_*Common`, `Pset_ManufacturerTypeInformation`
   and similar); drop analysis and fabrication property sets.
4. Drop or simplify geometry: COBie needs placement and identity, not
   parametric detail.
5. Keep `IfcSystem`, `IfcZone`, `IfcTask`, document and contact data.

The result conforms to the Basic FM Handover MVD. See `ifc-impl-mvd-export`
for the general MVD-subset mechanics and `ifc-core-mvd` for the MVD model.

## Anti-Patterns

Full detail with the failure mechanism is in `references/anti-patterns.md`.
The ones that matter most:

- Treating COBie as a geometry format and exporting parametric solids.
  COBie carries non-graphic FM data only.
- Inventing an `IfcCobie*` entity. COBie data ALWAYS lives in standard IFC
  entities; there is no COBie-specific schema.
- Mapping a Component to a type object. A Component is a placed occurrence;
  the Type is the shared `IfcElementType`.
- Putting per-instance data (asset tag, serial number) on the Type. The
  Type holds catalogue data shared by every occurrence.
- Mixing IFC2x3 and IFC4 entity forms in one COBie file. Bind to the single
  schema in `FILE_SCHEMA`.
- Editing the COBie spreadsheet in isolation. The IFC model stays
  authoritative; spreadsheet-only edits drift from the model.

## Reference Links

### This skill

- `references/methods.md`: every COBie-relevant IFC entity with attribute
  signatures, the relationships that wire them, and version notes.
- `references/examples.md`: verified STEP physical file instances per COBie
  worksheet.
- `references/anti-patterns.md`: COBie export failure modes and root causes.

### Related skills

- `ifc-core-mvd`: the Model View Definition model and the four MVDs.
- `ifc-impl-mvd-export`: extracting any MVD subset from a full model.
- `ifc-impl-property-extraction`: reading the property sets COBie carries.
- `ifc-impl-data-enrichment`: attaching the FM property sets COBie needs.
- `ifc-impl-spatial-decomposition`: the Facility, Floor, Space backbone.

### Official sources

- MVD database: https://technical.buildingsmart.org/standards/ifc/mvd/mvd-database/
- COBie certification: https://cobiecert.buildingsmart.org/
- IfcZone: https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcZone.htm
- IfcSystem: https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcSystem.htm
- IfcTask: https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcTask.htm
- IfcDocumentReference: https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcDocumentReference.htm