IFC is a format for exchanging models with data attached between different software. IFC elements are 3D construction elements and objects. IFC has nothing too with plans, annotation, or anything 2D.
The only consultant I have worked with is StructureCo, which is a pseudonym. The type of work is custom residential -- mostly wood members with some steel. This is our first try at this type of coordination.
My goals for the StructureCo collaboration:
• If I can get the beams labeled in the sections, and check that the structural elements fit, I can let them do the framing plans.
• Automatically label elements based on data provided within them, such as ID or profile.
• Let their layer names come through, with an extension.
• Bring in elements with proper classification.
• Avoid creation of attributes other than Complex Profiles.
• Let the consultant do the model 'their way' as much as possible. We try to be low-maintenance teammates.
In other words, let them do some of the work without sacrificing the consistency of our model and annotation process.
For structure coordination, think of our exported model as background plans in 3D form. Only the main model should be shown.
IFC publication is similar to DWG export. You need a view, with the proper settings, and you need a translator. We're using the default General translator until someone has a problem with it.
Layers:
Turn off all the trim and fixtures. The model is basically walls, floors, roofs, beams, columns, and the site.
Element Types to Show in 3D:
This lightly-used control is at View > Elements in 3D View > Filter and Cut Elements in 3D. It is saved with the view.
Turning off the doors, windows, and skylights simplifies the model while keeping the openings.
Graphic Overrides and Model View Options have no effect.
The translator is a set of rules describing how the IFC model should be handled when it is brought into Archicad. IMO these models should always be hotlinked, but the same rules would apply for merging.
You can use translators in the current project or refer to translators in a template file. They can also be imported from templates or PLNs. The translator is selected in the Open dialog box where you select the IFC file for hotlinking. It is part of the process of placing the hotlink.
StructureCo use Revit, but I don't now how 'vanilla' their Revit usage is. In the Archicad 22 template, there is a translator for Revit Structure, but I made StructureCo their own translator anyway. It looks like import translation is important to customize, and we will probably have a translator for each consultant.
Translators are at File > Interoperability > IFC > IFC Translators.
Model Filter:
What elements are imported
All 3D Elements. It's up to the consultant to limit the content. We can control visibility with layers.
Type Mapping:
How elements are classified
ARCHICAD Classification - 22 for import. The default.
Property Mapping:
Archicad Properties. This tries to match IFC properties in the IFC file to AC properties, and it basically works. If the consultant needed to attach data to elements that didn't work with the ID field, we would need to map those properties to AC properties. That situation hasn't arisen, so no additional properties are mapped at this time.
Geometry Conversion:
What element types are used
Parametric Construction and MEP Elements. Things will be what you expect (beams, columns, etc.) unless they are strange, in which case they will be objects or morphs. Morphs seem better to me because they can maintain the Building Material.
Layer Conversion:
What layers are used, and are new layers created
Create new layers to keep original layer structure. The other option is to map their layers to ours individually. I would rather keep all their stuff on "their" layers. The new layers will have an extension, which makes them easy to spot. I like to name the consultant in the extension, so it's "IFC StructureCo".
You have to modify layer combinations to have these layers show where appropriate. For the structure model, this is Working Model and the section combos.
When hotlinking, you need a module control layer. For the structure model, I'm using Z Module: Structure. In my opinion, they can be named by discipline instead of consultant.
Material and Surface Conversion:
What Building Materials and Surfaces are used, and are new ones created
I don't want new attributes created.
In my StructureCo preset, I imported their materials and mapped them to ours. They only use about 7 materials, for wood, concrete, CMU, and steel.
The way you find out what materials they use is to Merge from IFC, and bring in the IFC file you were sent.
You want to Override materials with mapping, and not override Material colors. This creates elements made of our Building Materials with no overrides, and no new attributes are added.
Pens:
Pens (and line types) aren't addressed by the translator.
Pen and line type settings of hotlinked elements come from the default settings of the relevant tools in the file containing the translator used to import/hotlink. If the translator is in the current file, you can control these settings ahead of time. If using a translator in another template, elements will have the default settings in that file as saved.
Custom Profiles:
Custom profiles are used to make steel beams and columns. In the StructureCo case, the new profiles are simply named with the shape designation.
Unfortunately, if you update the hotlink to point to a new version of the IFC, all the profiles get imported again, with a (1) after the name. The only way to fix this is to delete and replace each one.
Elements come in with their specification (wood member and quantity, or steel shape name) as part of the element ID.
To label the elements, you need an Archicad property made of an expression to extract the spec part of the ID text and discard the rest. Then you use an autotext label to call out that property.
For example, a certain wood beam has the ID "Framing--Dimension Lumber:(2) 2x10:977509". The part we want is "(2) 2X10".
Briefly, the expression takes the ID, cuts it into pieces defined by the colons, and keeps only the second piece. I call this property ID Split by ":" Part 2, with isn't pretty but it is clear. The actual content of the expression is SPLIT ( Element ID, ":", 2 )
Then all you need to do is place an associated label with the autotext for that property.
Elements must be classified for this to work. Unclassified elements can't have properties attached.
When you receive a new version of the IFC, change the hotlink to point at the new version. (IFC files should have a date in their names, and the old versions should be kept.)
Labels placed on hotlinked elements will update automatically if their specs have changed.
You don't correct it. The consultant has to do it. You can call their attention to mistakes and changes, but most important is to keep them updated with an IFC of the current state of our model.