Floor / slab
Bjälklag
A horizontal structural and separating element, usually the largest single carbon item in a building.
Floors category, a floor type with compound layers; structural flag for load-bearing slabs
IfcSlab typed by IfcSlabType, PredefinedType FLOOR or BASESLAB
floors
Area (m²) per layer and volume (m³) for cast layers, from the extracted model version
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 (carrying, separating), then Constructive systems | Carrying function first; hollow-core, cast-in-place or timber cassette second. |
| BIP | Object designation plus load and fire property designations | Makes structural intent readable across the structural and architectural models. |
| BK04 | Group and article per layer — concrete, reinforcement, insulation, screed | Reached once the recipe has stated each layer requirement. |
Identity → classification → contract → recipe → material requirements → product → cost → carbon. Concrete volume drives both cost and the climate declaration.
- Gross and net slab area differ once openings are deducted; a receipt must say which basis it used.
- Reinforcement is usually not modelled as geometry and must be declared by a recipe, not inferred from the slab.
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.
Decision receipts: proving why a construction choice was made
A receipt is not a report. It is the reconstructable record of one decision: its scope, its evidence, the rules applied, and the exact versions in force.