The following pages describe typical workflows between architects and three other professions: structural, MEP, and energy analysis engineers.
This section is a general description of the typical issues to consider if you plan to exchange data between ARCHICAD and a Structural application.
Analysis and design applications
These applications carry out and document static and design (steel, reinforced concrete, timber etc.) calculations based on various techniques (such as finite element method).
These carry out preparatory tasks and ensure the connection between the analysis application and the architectural profession.
These create detailed construction documentation of the structure (steel, reinforced concrete, precast, etc.) and communicate with the manufacturers.
This diagram describes the general workflow for data exchange between ARCHICAD and a structural application:
The most complete level of interoperability is achieved using an intelligent 3D model connection – as opposed to a drawing representation – in which the building model being exchanged represents 3D structural objects (slabs, walls, columns, beams, roofs etc.), each with specific, defined attributes and properties.
Model-based exchange between the architect and the structural engineer can follow one of two concepts:
The reference model concept ensures the “security” of the architectural model and the structural model files, since each office remains responsible for his/her own model. Thus, the structural engineer receives a file from the architect, but does not modify it; he/she uses the architectural information as a basis for building up his own structural model. This occurs manually, using the tools of his own software, but automatic element conversion utilities also exist to speed up the process. Similarly, the architect leaves intact the file received from the structural engineer, while taking into account its suggestions for modeling load-bearing elements. This way, each discipline’s own file is independent of the one received as a reference.
This is often a sensible workflow, given that the architect’s model differs from that of the engineer. For example, when modeling a multi-story building, the architect might base the initial design on a multi-story column that runs through all the stories, whereas the structural engineer might put a separate column on each story. In another example, the architect would use a single slab to model an area for which the engineer or detailer would use hollow-core slab elements.
The other approach to model-based exchange is to convert the other party’s model elements into the native format of one’s own application. The converted model is transformed according to the specifications of the recipient, so the original version of the model is not preserved. This approach is most typical of data exchange between architectural and analysis programs.
ARCHICAD can combine the advantages of both approaches. The 3D model obtained from the structural engineer – regardless of the method used to import it – is always transformed into native ARCHICAD elements. At the same time, it is possible to use the imported elements as a reference, since they can be automatically placed onto their own, protected layers (which are locked to prevent editing). This reference-model approach is also supported by the Merge and Link workflows.
Since the incoming elements or modifications are converted into native format, they become an active part of the architectural model, while retaining their properties (e.g. material, profile) assigned in the structural model.
The 3D models exchanged between the architectural and structural disciplines can be considered in three categories:
The architect works on the architectural model, based on her own design and on the client’s requirements. Already during the design phase, the architect should keep in mind that the model will later be exchanged with a structural engineer.
For example, she can define the building elements’ structural function; define initial materials to be used; choose columns and beams with standard profiles; define the load-bearing core of composite elements.
In addition to this preparatory work, she can filter the model so as to narrow down the data to be exchanged: this way, only the structural model, containing just structural elements, will be exported. Naturally, the architect can export the entire architectural model, if the structural engineer’s program is capable of filtering and collecting the model data that he/she needs to work with.
Exporting a structural model from ARCHICAD is sufficient for data exchange with most structural applications (the “management” and “detailer” types). However, analysis and design softwares require the so-called Analysis model in order to run their calculations. These applications can often convert the structural model to Analysis model themselves, or they can use the Analysis model converted by a management/detailer program as the input.
An Analysis model is a 2D or 3D representation of the structural model that includes not only planes (in the case of wall, slab, roof elements) and axes (columns and beams) of elements, but also their structural characteristics (e.g. stiffness, material, profile). The simplified analysis model also differs geometrically from the structural model: for example, curved surfaces are represented as a collection of planes; element intersections may be modified.
The export and import of 3D model data often takes place using a standard known as IFC (Industry Foundation Classes), which is actively supported by many design applications. In addition, many applications provide native Add-Ons for data exchange with other specific programs.
IFC-based data exchange can be enhanced by using the so-called BIM Collaboration Format (BCF)-based communication. In this workflow, you can assign comment topics to IFC model elements. Based on these, the other user can easily locate the referenced elements in the IFC model. BCF-based data exchange is particularly suited for identifying overlaps (e.g. collisions, modeling and other mistakes) when several models from different applications are combined in one program (e.g. ARCHICAD or a model checker).
Some engineers or applications (especially analysis applications) will just exchange data at the most basic level: they import CAD drawings (that is, the lines and points representing floor plans, sections and elevations), and use them as a reference for building the analysis model.
Models and drawings are often accompanied by other documentation, such as suggestions or reports; the most commonly used format for these is PDF.
ARCHICAD contains a number of techniques for displaying the structural model and for differentiating it from the architectural design.
In addition, ARCHICAD can interpret and store the imported structural data, such as the proposed or utilized materials, and the properties of profile elements.
Consultation and data exchange between structural and architectural offices generally requires several “round trips”. ARCHICAD’s Trace and Reference tool and a model-based change management feature helps to keep this process transparent.
This general architectural-structural workflow is explained in greater detail via the example workflows described below, which involve the interchange of model data between ARCHICAD and selected structural applications.
This section is a general description of the typical issues to consider if you plan to exchange data between ARCHICAD and an MEP application.
The first step of data exchange between ARCHICAD and external MEP software is the export of the architectural model. In order to optimize data exchange, export only the building elements and information the MEP engineer needs (e.g. load bearing structures, elements of the building envelope, boundaries of the interior spaces, lighting placement, built in equipment and furniture, suspended ceilings, space functions and numbering).
For MEP experts who work in a 2D design environment, create DWG files from the ARCHICAD model, preferably using a Publisher Set with pre-configured settings, in order to enable easy repeated documentation of the most current state of the project.
For providing data to engineers with MEP software, use GRAPHISOFT’s translator-based IFC data exchange feature.
When handling architectural data provided by ARCHICAD in MEP software, use the architectural content as an external reference. MEP software users using 2D solutions are advised to XREF the architectural DWGs, while MEP software users using model applications are encouraged to create a project link.
From 2D design environments, MEP data arrives as DWG (including the structural grid) and is placed as XREF or as Drawing into the ARCHICAD building model. Data from model-based MEP programs arrive in IFC format, via software-specific export extensions, developed by GRAPHISOFT or the MEP software manufacturer, allowing seamless design integration.
GRAPHISOFT MEP Modeler users can modify objects imported from AutoCAD MEP and Revit MEP or detect collisions between them and ARCHICAD model elements, since external MEP elements brought in via IFC file import translate automatically into native GRAPHISOFT MEP Modeler objects. ARCHICAD users without valid GRAPHISOFT MEP Modeler license receive MEP objects as individual ARCHICAD library parts.
IFC-based data exchange can be enhanced by using the so-called BIM Collaboration Format (BCF)-based communication. In this workflow, you can assign comment topics to IFC model elements. Based on these, the other user can easily locate the referenced elements in the IFC model. BCF-based data exchange is particularly suited for marking changes or collisions (e.g. between architectural and structural elements). In addition to ARCHICAD, many other applications support BCF-based collaboration.
Energy Evaluation is a dynamic energy balance simulation function integrated in ARCHICAD, enabling architects to perform accurate building energy evaluations.
It is also possible to export ARCHICAD building geometry data to external energy analysis software tools via IFC or Excel. Use ARCHICAD’s Save as IFC function or the Geometry Data page of the XLS Energy Performance Report spreadsheet to extract data from the architectural model that are required for external energy calculation software.
Since the energy expert produces written documentation, as opposed to modifying the BIM model, the import of energy analysis results from external applications back into the ARCHICAD environment is not supported.