Before handing an ARCHICAD file over to an MEP engineer using MEP-specific software, certain simplifications have to be made to the architectural model. Like structural engineers, MEP experts need only certain parts of the project – those which are relevant to their work. Naturally, the workflows of the two disciplines are not exactly the same. While the structural specialist must often modify existing parts of the project (e.g. widening a slab, increasing or decreasing the diameter of beams and columns, or changing their position) as well as adding new elements, the MEP engineer typically adds equipment, while trying to avoid the designed geometry of the load bearing structures.
Layers containing elements of the architectural model that are irrelevant to the MEP design should be switched off and thus excluded from the export data. Irrelevant elements are usually these:
It is possible to define separate layer combinations that specify content suited for the electrical, plumbing, lighting, acoustic, low current system engineer or elevator design specialist.
The two most commonly used file formats to export ARCHICAD data to MEP applications are DWG and IFC.
The majority of MEP engineers work in a 2D design environment (mostly Autodesk AutoCAD) and therefore wish to receive AutoCAD DWG files.
In ARCHICAD, the architect creates DWG files by defining floor plan, section or elevation views, and exporting these, rather than exporting the 3D model itself. It is advisable to create a Publisher Set with pre-configured settings in ARCHICAD to enable easy creation of the documentation to be handed over to the MEP expert. This way, the preset views representing the most up-to-date state of the project may be saved in the specified destination folder in DWG format, by a touch of a button.
Some MEP engineers design directly in a 3D work environment (AutoCAD MEP or Revit MEP). To fit this workflow, GRAPHISOFT has developed a translator-based IFC data exchange feature.
This feature translates the ARCHICAD model to IFC, which is currently the most advanced BIM model exchange format. When creating IFC content for the MEP specialist, it is advisable to set up a IFC translator customized for your needs.
From the Save as (IFC) dialog box, select “Entire project” as the Export option. It is also advisable to include the structural grid system in the IFC data, as the basis of reference for 3D element positioning.
Many MEP applications support BIM Collaboration Format (BCF)-based communication as an enhancement to IFC-based data exchange. The BCF workflow enables participants to add comments to the overlapping issues (e.g. collisions). BCF comments include the referenced IFC elements’ GUIDs and an attached preview (snapshot) picture; these enable users to easily locate the “problematic” model elements in the referenced view, using the same exact camera position as the snapshot. ARCHICAD’s Mark-Up tool supports BCF commenting, import and export.