AEC

new tools deliver BIM data

1 Dec, 2003 By: AIA ,H. Edward Goldberg


All the recent hype about BIM (building information modeling) piqued my curiosity about just how capable this generation of software is at producing useful information. Conceptually, BIM, a term coined by Autodesk and promoted by Jerry Laiserin, is a 3D virtual building model. Data associated with the model contains information on all building components. This data is available for use throughout the entire building cycle-the design, construction, and facility management stages of a project.

To my surprise, I uncovered several software solutions that extract information from a BIM. This article discusses some of these options, specifically Autodesk's Revit and Architectural Desktop 2004, Bentley Architecture 8.1, Graphisoft's ArchiCAD 8.3, and InterSpec's e-SPECS.

UNDERSTAND THE FORMAT
A better understanding of the nature of these information solutions requires familiarity with the CSI MasterFormat and UniFormat numbering systems, the IFC (Industry Foundation Classes) standard, and the ODBC (open database connectivity) format. The CSI MasterFormat standard is a 16-division, material-specific organizational format. The UniFormat, a more detailed numbering system, breaks building systems into categories such as foundation, superstructure, shell, and interior construction, and into subcategories such as floor and roof construction and exterior walls and windows. AEC designers use both systems to organize documents and specifications. See CSINet for a more complete explanation of these formats.

The IFC standard was developed by the IAI (International Alliance for Interoperability) to handle 3D file data. Major CAD vendors helped develop the standard and the tools to support it. The IAI is a division of the ISO (International Standards Organization), the body that controls the IGES and STEP data standards.

The IFC system is a data representation standard and file format used to define architectural and construction-related CAD graphic data as 3D real-world objects. Its main purpose is to provide architectural CAD users with the ability to exchange data between complementary applications such as CAD and estimating tools. The IFC system provides a set of definitions for all object element types encountered in the building industry and a text-based structure for storing those definitions in a data file. It uses a plain text file, the only truly universal computer data format. Individual CAD developers store data in whatever compact binary file format best suits their system. To implement the IFC standard, each CAD company must create programming within its own software structure. The developers provide Save As IFC and Read IFC commands, which map the IFC object definitions to their CAD system's representations of these objects.

As of this writing, Graphisoft and Bentley have implemented and enabled export capabilities for IFC 2. Bentley's building applications support 2.x, the latest version of the IFC standard. In addition, Timberline's estimating software, CAD Integrator Module, supports the IFC 2 standard for import of IFC data from any IFC application.

ODBC format is a standard database access method developed by Microsoft. The goal of ODBC is to enable access to any data from any application, regardless of the DBMS (database management system) handling the data. ODBC inserts a middle layer, called a database driver, between an application and the DBMS, which translates the application's data queries into commands that the DBMS understands. Both the application and the DBMS must be ODBC-compliant-that is, the application must be capable of issuing ODBC commands and the DBMS must be able to respond to them.

GRAPHISOFT'S ARCHICAD 8.3, RCC UNIFORMAT DATABASE
A compelling third-party software solution that leverages BIM recently appeared on my radar screen. Rich Creveling, a programmer in Colorado with a construction industry background, created the RCC UniFormat Database, a product that bridges the gulf between 3D models created in ArchiCAD 8.3 and Timberline Estimating Software. RCC's integration with Timberline estimating software via IFC 2 exchange is a significant and powerful innovation. The RCC Favorites Library component of the RCC UniFormat Database is now included with ArchiCAD 8.3 (figure 1).

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Figure 1. ArchiCAD 8.3 includes the RCC Favorites Library component of the RCC UniFormat Database.

The RCC includes a large body of architectural content such as beams, columns, doors, slabs, walls, windows, floors, decks, and roofs. As an example of its vastness, the library defines more than 80 types of typical wall composites. Using the IFC-based Timberline CAD Integrator, you can leverage building models created with the ArchiCAD RCC Favorites Library to derive detailed commodity-level construction cost estimates in seconds.

Because the RCC UniFormat Database and accompanying object library definitions support the IFC 2 standard, they provide machine- readable architectural content for automated cost estimating. This data also features attributes you can use to integrate purchasing, scheduling, and accounting applications. According to Creveling, he has had discussions with other design software vendors, including Bentley Systems, about developing similar object libraries for their products. He's happy to continue to work with Graphisoft because he believes that Graphisoft has done a great job of developing ArchiCAD from the ground up to support IFCs.

The RCC Database builds information to UniFormat level 6, encompassing stud counts, amount of mortar, lengths of rebar, and so forth. For about $4,000, you can purchase the RCC Database. This, along with Timberline's Estimating Software and CAD Integrator, allows you to output any type of estimate in about 60 seconds (figure 2).

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Figure 2. The RCC UniFormat Database, working withTimberline’s Estimating Software and CAD Integrator, outputs any type of estimate in about a minute.

What-if estimates are available at any stage of design, and the estimate changes as you modify the design.

AUTODESK REVIT
Revit offers two ways to generate estimating quantities. It can automatically label quantities with UniFormat II classification Level 4 information, such as material, area, and volume (figure 3).

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Figure 3. Revit generates estimating quantities that are automatically labeled with UniFormat II classification level 4 information, such as material, area, and volume.

One method exports to ODBC format. Using this format, you can export to Microsoft Access database software all the data contained in Revit's 3D building model, an extensive list of footings, piers, walls, roofs, windows, doors, finishes, and furniture. From the OBDC output, you can craft custom database spreadsheets that automatically create and update estimates. Autodesk's Ken Stowe, product manager for construction, has created creditable estimates using this output. Any third-party estimating, planning, procurement, and facility management tools that use the ODBC format can work with Revit data.

The second method uses preprocessed, user-defined ASCII BOM (bill of materials) tables. You can use comma-delimited output from Revit's standard schedules to provide data for Microsoft Excel and other spreadsheets. You essentially have two choices: format your quantities output inside Revit and export it, or export it and then format your data.

For 4D construction simulation, you can tag all of Revit's objects with construction-sequence information, so you can generate 4D storyboards and animations with logistics, equipment, and safety elements for presentations and owner decision-making meetings.

AUTODESK ARCHITECTURAL DESKTOP 2004
There are probably more seats of Architectural Desktop in use than any other architectural CAD software. For software subscribers, the new Interoperability and Productivity Extension provides enhanced design workflow tools and smooth data sharing among team members.

Do you need to distribute more than just graphic data? With DWF files, you can view nongraphic information as well as design graphics to make design intent more clear. The free Autodesk Express Viewer displays nongraphical data such as the fire rating of a door and the square footage of a room. The DWF format also lets design team members review and redline, making DWF an efficient means to distribute and share data.

Using Autodesk MapGuide, you can convert pertinent digital design data contained in Architectural Desktop drawings into informative and interactive facility maps (figure 4).

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Figure 4. Autodesk MapGuide transfers Architectural Desktop design data into informative and interactive facility maps.

With this tool, you can give other industry professionals, such as facilities managers, quick access to building areas and their corresponding resources.

Autodesk Architectural Desktop now exports the data in drawings to Microsoft Access, where you can view, sort, query, and export it to other applications to perform specific tasks, such as cost estimation.

Often forgotten are Architectural Desktop's scheduling features, which provide the ability to generate BOMs and basic estimates directly in the model. The objects support a cost property so you can, for example, wcreate a door schedule that includes individual and total cost for doors. An IFC 2.x plug-in is available for ADT.

BENTLEY'S BUILDING SOLUTIONS
Bentley approaches BIM with a multidisciplinary set of solutions. Bentley Architecture, the architectural design and documentation application, supports IFC information exchange. Bentley's building solutions are built on MicroStation and incorporate TriForma technology. Because of this, each application does full quantity takeoffs and cost estimating in conjunction with tools such as Excel or Access. You can exchange information in a variety of formats, including DWG and XML.

Bentley supports MasterFormat and UniFormat, and its new IFC capabilities should add even more flexiblity. It would be great to see the RCC database work with Bentley Architecture-that would truly demonstrate the value of IFCs for common data exchange!

Bentley's Schedule Simulator was probably the first commercial 4D product for AEC when it debuted several years ago. The latest version is now included in Bentley Navigator. With its automated interference detection tools, Schedule Simulator lets you link model objects to schedule tasks in Microsoft Project or Primavera P3 so you can present and analyze your design throughout construction.

Bentley Facilities, made for building operations and management, is fully integrated with Bentley's design tools and supports AutoCAD drawings. It extends the use of a building model into the operational life of the building, with full space and asset management capabilities as well as interactive facility maps, all accessible through just a Web browser.

INTERSPEC E-SPECS
For AutoCAD and Architectural Desktop users, InterSpec's e-SPECS automates specifications by extracting product and material requirements directly from the project drawings (figure 5).

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Figure 5. e-SPECS automates specifications by extracting product and material requirements from project drawings.

For unique items, e-SPECS links to Master Guide specifications and presents only the language required to specify the product or material identified. It can even link to existing office masters and create custom office masters on the fly, eliminating any compromises on quality and accuracy created by cutting and pasting sections from previous projects. The old method carries an inevitable risk of including irrelevant language or excluding relevant language. Incomplete, poor-quality, and inaccurate specifications can affect value engineering in design and potential construction cost savings, as well as increase exposure to litigation.

Using e-SPECS, an entire project team can collaborate on specification documents from anywhere. Team members access the project using e-SPECS on their computer or from any Web browser to review and edit specifications and create and respond to project notes. e-SPECS version control tracks all user edits and makes it possible to incorporate comments and changes from multiple sources.

HOW IMPORTANT IS INFORMATION FROM A BIM?
One goal of all the solutions mentioned here is to let you track construction costs during the design phase and offer alternative concepts based on budgets. This raises the question, "Can I increase fees for the additional service of answering these what-if questions during the design process?" Having instantaneous access to data embedded in the design should also shorten the bid process, potentially decreasing bidding costs.

All these savings accrue to the client and the contractor. Though it's easy to appreciate the inherent value of the information, at this early stage in technology development you can only speculate on the monetary value of this information to the profession of design and the practice of architecture.

In this shifting paradigm, with no existing corollary, the ultimate effect on the bottom line-whether or not you can ask for compensation for all the nongraphical information included in the building model-is the next uncharted territory.


AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!
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