Importing a digital building model (from Archicad, RevIt, ArchLine, FreeCad, Cadworks, Sketchup, etc.) with COCON-BIM

For ease of use and to facilitate exchanges between different software applications and users, a digital building model (BIM) has to be entered in line with a few basic principles.

To perform a life-cycle analysis of a building, COCON-BIM uses a digital model (BIM) exported from a 3D drawing application.

Follow these main recommendations for producing easy-to-use digital models :

  • Format :
    • Export the BIM in IFC format (versions Ifc 2x3 or Ifc 4).
    • Generate the IFC file using the “basic quantities” option in the IFC export parameters. This option allows the measurements of objects (volume of walls, area of rooms, etc. to be exported in a standard form.
    • Many software applications can export in IFC format, such as :
      • Archicad :
        • Procedure 1 (as appropriate, depending on Archicad version)
          • "File" menu => "Save as...". => "IFC format"
          • Select or configure a translator that exports the basic quantities (IfcBaseQuantities) => "COBie 2" for example.
        • Procedure 2 (as appropriate, depending on Archicad version)
          • Interoperability -> IFC -> IFC translators,
          • Select Export General, IFC 2x3, COBie 2.4, and in "data conversion", select "All BIM data".
      • ArchLine
        • "File" menu => "Export IFC"
      • FreeCad (free software)
        • "File" menu => "Save as...". => "IFC format"
      • Revit :
        • "File" menu => "Export" => "IFC format"
        • Select or configure options that contain the basic quantities (IfcBaseQuantities) => "GSA Concept Design" for example.
      • VectorWorks
        • "File" menu => "Export" => "IFC format"
        • Select "Version 2X3"
        • Select an export model => "Cobie" or "IES VE"
      • Cadworks
        • "File" menu => "Export" => "IFC format"
        • Note that Cadworks cannot currently export the basic quantities (Ifc BaseQuantities) in the IFC file. It is possible to add the missing information via another application such as SimpleBim (menu "Run tools => Calculate Basic Quantities").
      • Sketchup PRO version only
        • "File" menu => "Export" => "IFC format"
        • Note that Sketchup Pro cannot currently export the basic quantities (Ifc BaseQuantities) in the IFC file. It is possible to add the missing information via another application such as SimpleBim (menu "Run tools => Calculate Basic Quantities").
    • Organisation of the digital model (BIM).
      • Create one file per building organised hierarchically as follows : Project > Site > Building > Level > Space.
      • If the building is complex, it is worth creating one file per storey.
      • The elements that make up the building should be modelled by the objects that best describe them. For example, if the structure includes columns, they should be described as objects in the column class (IfcColumn). We therefore recommended using the dedicated tools offered by the software used to produce the digital model ("wall" tool, "slab" tool to create slabs or floors, "roof" tool, etc.).
      • The levels correspond to the different altitudes !! of the top faces of the floors of the building can be named using the following coding :
        • Ground floor
          • 00 in the most common case
          • 0B and 0H if you need to distinguish between lower and upper ground floors.
        • Intermediate floors : 0102, etc.
        • Basements
          • S if the building has only one
          • S1S2, ... if you need to distinguish several levels
        • Mezzanines
          • M if the building has only one
          • M1M2, ... if you need to distinguish several levels
        • Crawl spaces
          • V if the building has only one
          • V1V2, ... if you need to distinguish several levels
        • Top level TO which corresponds to :
          • a flat roof on the upper face of the top floor
          • for other types of roof, the upper face of the floor supporting the attic space
    •  Tips on inputting and content for IFC files

    If the content of the composite walls (formed of several layers of materials) is entered in 3D, this information is re-used by COCON-BIM to facilitate the entry of the walls during the environmental analysis.

The table below sums up the main recommendations for producing clearly organised and easy-to- use digital models.

Building element

IFC object to be used

Entry recommendation

Exterior walls

IfcWall

IfcWallStandardCase

Broken down into one element per level. 

Curtain walls

IfcCurtainWall

Party walls, partitions

IfcWall or IfcWallStandardCase

Slabs, floors

IfcSlab

 

Roofs

IfcRoof

 

Exterior and interior windows

IfcWindow

 

Exterior and interior doors and French doors

IfcDoor

 

Columns

IfcColumn

 

Beams

IfcBeam

 

Stairs

IfcStair

 

Rooms and spaces

IfcSpace

 All rooms and spaces, whether or not closed or covered.