IFC (BIM)

IFC is the open standard for exchanging building models (ISO 16739, developed by buildingSMART). It is the language BIM programs use to talk to each other: Revit, ArchiCAD, Tekla, Solibri and FreeCAD read IFC no matter what the model was created in.

OpenStreetMap maps are exported to IFC for the sake of building context — the neighboring buildings around a site against which a new object is designed. It saves time at the concept stage: the surroundings do not have to be modeled by hand or traced off a satellite image.

The file holds a full IfcProject → IfcSite → IfcBuilding hierarchy: every OSM building becomes a separate object with an extruded body following the house outline. Height is taken from the height and building:levels tags, and when they are missing a value is substituted by building type. Each building carries an OSM2CDR_BuildingProperties property set: height, computed floor count, name, address and the functional type mapped to the IFC nomenclature — residential, commercial, industrial.

The level of detail is LOD1: volumes following the outline, with no pitched roofs, floor slabs, windows or interior rooms. Coordinates are local and metric with the origin at the center of the area, while the extent in degrees is written into the project description, so when you insert the buildings into a working model they need to be aligned with your site.