Walls are one of the most basic building elements and they can act in several different roles. They have geometry, layer information and a construction/project type. Walls also act as space boundaries and have a relationship to the spaces they bound. Walls have calculated information, such as the average height and area, and they can have other attached information, like a fire rating.
Geometry
BoundingBox Extruded solid Linear Rectangular 1 No No Extruded solid Revolved Rectangular 1 No No Extruded solid Linear Rectangular 1 Yes No Extruded solid Revolved Rectangular 1 Yes No Brep
- Not slanted in the context of spaces means, that the extrusion direction is horizontal relative to the global Z-axis
- As the basic representation walls should always have a bounding box. The bounding box can be used as a place holder for walls with complex geometry in programs that are not able to support the given geometry. This could be the case e.g. in programs that don't support Brep representation.
- There are no strict rules for the bounding box of curved walls and in the current implementations the bounding box is not the best possible approximation. The bounding box for curved walls was implemented this way because it simplifies the coordinate transformations involved in using a revolved solid for this purpose.
- Walls that are straight or curved and have the same profile throughout the whole wall, are represented by an extruded or revolved (curved along the arc of a circle) solid.
- Both straight and curved walls can be clipped by any number of clipping planes. Clipping usually happens when a wall clipped by a roof, but also other clippings are allowed.
- Wall intersections are not cleaned up using clipping, instead the intersection is transferred as a logical connection between two walls and the actual cleanup is left to the receiving system.
- When using solids one wall uses only one solid with one segment. If programs internally allow more complex walls, e.g. the baseline may be a polyline then the wall has to be broken down to single segments for IFC.
- The material layers inside the wall are not modeled using geometry; instead they are transferred as material layer set information that is attached to the wall. Material layer set information may be shared between several wall instances.
- Openings in walls are not made in the wall geometry. Instead the wall can have associated opening elements that make the openings into the wall. See opening element for more details.
- When solids are used for the wall geometry the exchange files are more compact, the baseline (reference line) of the wall can be preserved and it is easier to derive quantities from the wall geometry.
- In all other cases the wall representation is made using a Brep.
- Non vertical (slanted) walls
- Walls with a varying profile (having a complex footprint)
- Curved walls along the arc of an ellipse, along a spline, nurb etc.
View considerations
- Arch. design >> Quantities take off / cost estimating
- Wall type
- Wall length, height and thickness
- Voids in walls
- Wall connections
- Arch. design >> Thermal load calculations / HVAC system design
- Wall type
- Relationship between walls and spaces / outside air
- Voids in walls (leads to voids in space boundaries)
Documents