Issue: Volume: 25 Issue: 8 (August 2002)

constructive analyses

By Jerry Laiserin

The notion of pre-construction, post-occupancy evaluation of buildings may sound like a hypothetical brain-teaser. But the best current AEC software actually combines the ability to manage geometry, or what a building looks like, with the data attributes of all the building components represented by that geometry.

Comprehensive sets of design and construction data, from specifications of building materials to operational characteristics of building equipment, can go beyond serving the design information needs of architects and their clients, such as defining the building's appearance, how people will move through it, and what will be their likely experience of the building's thermal, acoustical, illumination, and other performance characteristics (see "Six Degrees of Simulation," June 2001, pg. 30). The same data can be extended throughout the construction phase, the "C" in AEC, to help predict and manage the sequencing and scheduling of building components in accordance with a master project timetable, a process sometimes called 4D simulation (for the three spatial dimensions, plus time). True data-centric design has the capacity to carry material and equipment attributes forward after the construction phase into building operations or facility management.
TriForma V8 from Bentley supports an integrated portfolio of discipline-specific design tools (Structural for TriForma, Architectural for TriForma, HVAC, and so forth), all of which operate on a common set of model data for each building project (below).

The ability to support and manage data across the entire building life cycle, from pre-design planning through ongoing maintenance and management of the completed structure, increases the value of design above that of visualizing a building's appearance-important though that is. In effect, the new tools allow everyone in volved with a building to benefit from the databases behind the design. Conversely, such data-centric capabilities are becoming a benchmark for AEC-industry players in choosing their software tools.

More than just a pretty face
The best packages provide a comprehensive suite or portfolio of tools and functions to create, manage, and publish design data across multiple design disciplines, such as architectural, structural, mechanical, electrical, landscape, and so forth. And they are able to do so in multiple dimensions, such as 2D "drawings," 3D "virtual building" models, and 4D schedule simulations. One of the most complete portfolios is offered by Bentley Systems in its recently released TriForma family of products that is built on top of the company's flagship MicroStation V8 software platform.

A key innovation in V8 is the ability to read and write both Bentley's DGN file format and the DWG format of Bentley's larger competitor, Autodesk, interchangeably on the same project. This file-level compatibility enables users of V8 and TriForma to share their design data with other users representing roughly 80 percent of the AEC market, making their data the most widely and easily accessible in the industry.

Discipline-specific "flavors" of TriForma, such as Architecture for TriForma, Structural for TriForma, and so forth, share the underlying V8 functionality and format, but also allow each discipline to operate on just their respective views of the overall building model. This improves efficiency, since a heating, ventilating, and air conditioning (HVAC) designer need not be burdened with the on-screen and processor/memory overhead of structural or architectural data not relevant to the design task at hand. Any view can be fully modeled and rendered, to reveal a building's inner workings or structural system, for example, or to visualize the completed building as one walks around it under sunset skies.

You say you want a revolution?
While Bentley TriForma and V8 represent a significant achievement in the data-centric capabilities of a fully mature, feature-rich software lineup, a two-year-old product called Revit takes the opposite approach-starting with a data-centric core dubbed a "parametric change en gine," then expanding it to fill in all the AEC-required multi-dimensional and discipline-specific pieces. Although widely admired for its technology and marketing bravado, Revit (both the company and the eponymous product) gained little traction in the market and has recently been acquired by Autodesk to complement that company's other design, modeling, and data tools.

Revit made much of its "bi-directional associativity"-the ability to edit any part of a Revit design, even a detail, schedule, or dimension string-and have that change automatically ripple throughout the model (and vice versa). However, this marvel of internal consistency was achieved at the apparent expense of a relatively closed aspect toward external input. Revit offered competitive functionality in reading and writing the DWG and DGN file formats of its vastly larger competitors, but no other application can operate on a Revit RVT file. (Befitting the background of Revit's founders from Parametric Technology Corp., the RVT file format is held as proprietary and is not publicly documented).
Data-Centric AEC tools, such as Bentley Systems' Architecture for TriForma V8, used to create the surrounding images, contain full object-model intelligence and associated attributes that underlie both the rigorous building design model and the qualit

As a practical matter, this closed nature of Revit partially compromises the benefits to some users of the very data-centricity that formed the basis for the product's initial appeal. While competitors actively pursued industry-wide standards such as those of the International Alliance for Interoperability (IAI) or the Building Lifecycle Interoperable Software (BLIS) project, Revit chose to rely on data dumps (albeit ODBC-compliant data dumps) that the company called concurrent building assets (CBAs). Other competitors offered application programming interfaces (APIs) that effectively exposed some of their product's inner workings so that developers of analytic software, such as cost-estimating, construction-scheduling, energy simulation, and so forth, could program their own "hooks" into design data. Revit espoused the view that any programmability in a product was a sign of "incompleteness." But this conveniently glosses over the necessity for would-be users of Revit's CBAs to program and complete their own links to third-party analytic tools, in the absence of pre-programmed links via the unavailable Revit APIs.

Of course, such limitations may have been just a function of the naturally parochial view of an industry upstart. Now that Revit's technology is owned by market-leader Autodesk, AEC-industry players can hope to see the richly data-centric core functionality of the Revit product effectively leveraged into a broader and more compatible realm that enables future Revit users to capitalize on the benefits of their data.

Virtuality is its own reward
Among all the AEC design tools available, few can boast as long and consistent a history of data-centric orientation as ArchiCAD from Graphisoft, a company and product now celebrating their twentieth anniversary in the business. Almost from its inception, Graphisoft pioneered the data-centric view that it called the virtual building. As the capabilities of affordable hardware and user-friendly operating systems (both MacOS and Windows) caught up to Graphisoft's vision over the years, the company incorporated progressively more data functionality into its ArchiCAD product.

Today, ArchiCAD offers one of the best integrations of 2D and 3D drawing production and modeling, along with significant 4D phasing simulation. Comprehensive underlying data capabilities are expressed in Graphisoft's own fully programmable database language, GDL (Geometric Description Language) that facilitates exchange of ArchiCAD objects with the custom objects produced by Autodesk's Architectural Desk top. In addition, Graphisoft has been a leading participant, along with Microsoft and others, in the BLIS project, a group of companies shipping various design and analysis software packages that interoperate or share data through the IAI industry foundation classes (IFCs) version 2.0. Thus, ArchiCAD can take a Microsoft Visio diagram and turn it into a 3D building model, which can be analyzed by a wide range of estimating, scheduling, and performance analysis software-all without reentering or translating model data.

Recently, Graphisoft has begun integrating multi-discipline functionality into ArchiCAD, through third-party tools for structural design, or incorporating HVAC ductwork layouts into the building design. Through a strategic acquisition of the former DrawBase facility management program and unification with the in-house ArchiFM product, Graphisoft has extended the usefulness of its building data for facility management downstream of the design and construction phases.
Some self-contained design tools, such as Revit (recently acquired by Autodesk), avoid all conventional means of data-linking and data-sharing in favor of vendor-defined export dumps of vendor-determined model data in vendor-enumerated collections called

Not the only fish in the sea
While Bentley TriForma, Revit, and Graphisoft ArchiCAD are among the current leaders of the trend toward data-centric AEC design, they do not represent the entire picture. No AEC software story would be complete without mentioning the plans and products of market-leader Autodesk, which, like Graphisoft, is celebrating its twentieth anniversary in 2002. In addition to the newly acquired Revit and the core platform product AutoCAD2002, Autodesk offers AEC users Architectural Desktop 3.3 (ADT), which runs as an add-on to AutoCAD2002. ADT reflects the heritage of the third-party add-on family that Autodesk acquired a few years ago from Softdesk. Some of Softdesk's former multi-discipline functionality is re flected, in turn, in the Autodesk Building Mechanical (ABM) and Autodesk Building Electrical (ABE) add-ons to ADT. The acquisition of Revit gives Autodesk a two-pronged modeling strategy for the AEC market similar to the approach the company has successfully employed with its Inventor and Mechanical Desktop products for the mechanical design or MCAD market. Overall, Autodesk's data-centric strategy spans the entire design and documentation process, from the freehand sketch capture of Autodesk Architectural to the data-accurate global illumination rendering technology in Autodesk Viz.

Other important data-centric AEC design participants include Nemetschek North America, with its VectorWorks Architect and LandMark products (derived from the former MiniCAD product line), while the company's German parent, Nemetschek AG, waits just off-stage with its even more data-centric AllPlan product that is the market leader in the huge German AEC market.
One approach to data-centric design relies on the IFC Exchange system for model-sharing as implemented by the Building Lifecycle Interoperable Software Project (BLIS).

The ductwork layout shown was modeled in ArchiCAD-HVAC, an add-on to Graphisoft

Whether home grown or imported, built from scratch or patiently evolved, the current crop of data-centric AEC designware clearly represents the future of an information-intensive AEC industry.

Architect and industry analyst Jerry Laiserin, FAIA, MBA, publishes the LaiserinLetter, a weekly service that includes analysis, strategy, and opinion for technology leaders in design business. He can be reached at

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