The IFC should contain the following classes:
§ Spaces
(ifcSpace);
An IFC model without Spaces cannot be
imported. This also holds for rooms without a “Space” definition. The Spaces are
used in Vabi Elements to identify the rooms. It ensures that the list of rooms
corresponds correctly to the BIM model. Note that Spaces may not be overlapping.
Spaces may include multiple classes, such as zones, areas, rooms
(architectural), and spaces (installations). These classes may overlap. If you
import all classes at once, the spaces may overlap and errors may develop. We
advise to choose one class in the IFC, such as the rooms which appear in the
list of rooms in the BIM model.
The surface area and volume of the space
should be practically correct. Spaces which are lower or higher than the rooms
are imported wrong.
§ Walls (ifcWall, ifcWallStandardCase), slabs (ifcSlab) and roofs (ifcRoof);
The centre
point dimensions of the rooms are determined using the walls, slabs, and roofs.
If the software cannot find a wall, these centre point dimensions cannot be
determined and the outside air flows into the rooms. As a result all walls
become exterior walls and, consequently, the calculations are incorrect.
The IFC file may contain the following classes:
§ Windows
(ifcWindow), doors (ifcDoor) and curtain walls (ifcCurtainWall);
Windows, doors, and curtain walls are
recognized and imported as subfaces in the walls, slabs, and roofs. Naturally,
it is possible to import an IFC model without rooms, doors, and curtain
walls.
§ Columns
(ifcColumn);
Columns are not required, but they may
exist in the BIM model. If a column is present, it will be combined with the
room in which it is located in general.
Additional IFC classes are not imported for the building programs of Vabi Elements.
In case of an IFC export, it should be made sure the Architectural model is exported at least. The technical installation model does not contain the above IFC classes most of the time.