Sheet metal shop drawings and BIM drawing services

BIM has great momentum in construction documentation. The American Institute of Architects has defined BIM as "a model-based technology linked with a database of project information." With a true BIM model, an accurate 3D model of a building can be constructed digitally. This true BIM model has precise geometry and information to facilitate scheduling, cost comparisons, fabrication, construction, and facility operation.

Along with this comes a totally new work process that requires extensive data sharing among architects, engineering consultants, and contractors. This is such a radical change that the AIA released 6 new Contract Documents in October of 2008. These new documents are intended to allow all users to work in partnership and assign responsibilities in managing this true BIM model. The final result becomes the contractors map for construction management and then the building owners map for facility operation.

This is the "ideal" BIM world that has yet to be realized. In practice, a number of problems and limitations are being discovered in the real world. Among the ones affecting MEP contractors are:

1. The massive size and complexity of a fully loaded BIM model database presents major problems for existing computers and servers.
2. Several platforms have emerged. Autodesk® REVIT® (in several flavors), Bentley Systems® (in several flavors), and ArchiCAD® by Graphisoft® are the leading three. Interoperability for models from differing software packages is problematic.
3. Expecting every player on the project team to use the same software system is, at present, unrealistic. Each company has their own trusted and preferred software applications for their trade. These applications have likely been purpose built and highly optimized for the processes they support. Further, they have been customized for each contractor's fabrication and installation preferences.
4. The result of all of these varying files being loaded into a viewing system, such as Autodesk® Navisworks®, is a 3D model with severe limitations as true BIM model. While collision checking and coordination among the trades can well be done with this product, the intelligence of objects is lost in the translation. We simply have an accurate but dumb 3D model.

Today's CAD-based software applications being used by the MEP trades can create detailed models, generate fabrication information, and some will even generate installation information. However, they do not maintain all logical relationships when changes are made. For example, if a duct is relocated the other duct sections do not automatically follow suit. They must be manually reconnected. Also relationships to building elements do not follow the moved duct. If a floor, louver connection, or wall opening is involved, the affected building element does not automatically move itself and heal the previous location. A true BIM application would change everything associated with this duct move on the fly.

The available software for 3D duct systems such as Quickpen® DuctDesigner 3D® and Cadpipe® HVAC does not yet comply with the import and export interfaces required for true BIM models. They must at least support IFC (Industry Foundation Classes) before their "intelligence" follows them to a true BIM model. I have spoken to representatives of both companies and both are working in this direction. To date, neither product is to this point.

Therefore, RanStan, Inc. cannot, at this time, offer a true 3D BIM product. What we can offer is a 3D file that can be loaded into Autodesk® Navisworks® for coordination and collision checking. We can also offer anyone a no cost viewer that will allow anyone to open and view a drawing with its intelligence intact. These 3D drawings are currently based on Quickpen® DuctDesigner 3D®.

We are constantly reviewing available programs to see when a software application will allow RanStan, Inc. to produce a product for our clients that will be a true BIM model. As soon as this becomes available, we will implement it for our clients who need this capability.