Building Design

Cadalyst AEC Tech News #122 (June 17, 2004)

16 Jun, 2004

We've had a number of inquiries recently about the future availability of a set of applications for Revit that will be comparable to the Autodesk Building Systems part of the Autodesk Architectural Desktop software line. In the past, the Revit folks have consistently said they plan to develop such a building services engineering product for Revit. But they've been pretty quiet about it recently, and such a forthcoming development is no longer mentioned in Revit's marketing literature or on the Revit part of Autodesk's Web site.

This has caused me to be dubious in responding to the casual questions I've been asked on this subject. I doubt that such a product will be forthcoming any time soon. Autodesk has continued to develop and enhance the Building Systems product, creating quite a useful and usable application for building services engineers. Autodesk must be pretty heavily invested in the Building Systems product by now, with many years of development time and effort going back more than 10 years when you include the Softdesk applications that were the predecessors to Autodesk Building Systems. It doesn't seem to make a lot of sense for Autodesk to embark on the major effort and dollars it would take to develop an entirely new product for the Revit platform, given the limited market.

However, I also believe that the lack of tools for MEP engineering and modeling is a big hole in the use of Revit as a complete building information modeling system. Integrating HVAC equipment and ductwork, electrical systems, and plumbing and fire protection systems seems crucial to achieving a complete building information model. Being able to coordinate and check the location and arrangement of these systems in relation to the architectural elements of the building is a major advantage of using a complete 3D BIM system. And the MEP systems probably require more attention in the long-term use and occupancy of a building than even architectural systems. The lack of this type of information in the building information model limits its ongoing usefulness.

Autodesk has improved the workflow involved in using Revit interactively with other CAD systems by incorporating direct import and export of DWG files and by letting you link DWG reference files into the Revit design file. But this is by nature only a one-way link that requires a separate data export step. It's a long way from a true interactive and interoperable setup for working across multiple disciplines. And it doesn't support the Autodesk runtime extensions required to directly use data from Autodesk Building Systems or Architectural Desktop in Revit. So if your consulting engineers are using Autodesk Building Systems for their systems engineering and modeling, they have to save their drawings as simple CAD files for use with Revit without the intelligent object modeling that they normally use. Conversely, providing them with background files created with Revit requires the Revit user to convert the intelligent building model into a simple CAD file for use with Building Systems. Hardly a true two-way interoperable solution in my mind, but it's probably adequate for many non-BIM situations with only a few extra steps required for data exchange.

But Autodesk maintains that a wholly Revit solution for building systems engineering and modeling is still in the works, and development of Revit functionality for MEP is ongoing "in the background." I don't know what "in the background" means, except that it's unlikely that anything is imminent. Autodesk policy is not to discuss unannounced future products, so no information about a possible Revit solution for building services engineering or when it could be released is available. Frankly, I'll believe it when I see it as an actual product ready to ship and be used by customers, but Autodesk has surprised me in the past and an actual product may be closer than I think it is.

I have no real reason to doubt what Autodesk currently says about a Revit building engineering product except the speculation outlined above and the usual skepticism about anything related to nonexistent future software products. If I really needed a truly interoperable multidiscipline solution now, I wouldn't hold my breath waiting for the Revit product.