Roof
Tak
A climate-separating upper enclosure where the layer sequence, not the shape, drives requirements.
Roofs category, roof by footprint or extrusion, with a compound layer structure
IfcRoof, with slab components typed by IfcSlabType, PredefinedType ROOF
roofs
Sloped area (m²) per layer; volume (m³) for cast or poured layers
Where this element is normally designated in each Swedish reference system. Code values stay with their publishers.
| System | Designated in | What it establishes |
|---|---|---|
| CoClass | Functional systems (enclosing), then Constructive systems | Enclosure duty first; warm roof, cold roof or green roof as the constructive realisation. |
| BIP | Object designation plus U-value and moisture property designations | Makes the roof build-up comparable between models. |
| BK04 | Group and article per layer — membranes, insulation, battens, covering | Layer-level product candidates only. |
Identity → classification → contract → recipe. Waterproofing and insulation requirements arrive from regulation and the contract.
- Projected area and sloped area are different quantities; using the wrong one under-orders material.
- A roof modelled as a floor keeps its modelled identity and must be reclassified explicitly, never guessed.
BIM data is evidence, not authority
A parameter in a model is a claim made by whoever typed it. Treating claims as authority is how wrong numbers get inherited across an entire project.
What is construction decision infrastructure?
Models describe geometry. Decision infrastructure records the choice, the evidence behind it, the authority that governed it, and the receipt that proves it.