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AEC

Green Is Good

14 Jun, 2004 By: AIA ,Rick Rundell

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Today’s technologies let architects perform their own energy analyses

Last month we looked at how BIM (building information modeling) results in better building data. This month's article illustrates one way to leverage that better data -- architects now have the power to perform their own fast, accurate energy analysis on early-stage building designs, thereby promoting the construction of "green" buildings.

Designing a Greener Building
The LEED (Leadership in Energy and Environmental Design) Green Building Rating System is a national standard for developing resource-smart, sustainable buildings. As more people adopt the standard, many owners and operators are requiring that their new building projects earn LEED certification, which rates a project based on site design, indoor environmental quality, and efficient use of energy, materials, and water. A high LEED rating recognizes the quality of a green building design and qualifies the project for an array of state and local government financial incentives -- an important benefit for the building owner.

As you can imagine, complex engineering analysis of the design project is critical to achieving LEED certification. Many design firms typically outsource engineering analysis because it can be time-consuming and costly to do in-house. But now, BIM solutions such as Autodesk Revit provide robust design models that contain the necessary level of detail to complete these analyses. Designers can easily extract pertinent design data from the building information model and enter it into various analysis programs. The recently released Green Building Studio service, available at no charge from GeoPraxis, has streamlined this process to the point where architects can perform energy analysis in-house, reducing the cost of the design process.

Web-Based Analysis
GeoPraxis is an industry leader in developing and implementing building energy analysis tools and Web-based solutions. The company's Green Building Studio Web service and XML connectors integrate its analysis tools with BIM solutions such as Autodesk's Revit, Architectural Desktop, and Building Systems. Using these tools and the better information created in the building information model, architects now can more effectively test building performance and validate design options over the Internet.

"This is a huge breakthrough for green building design and LEED qualification," says John F. Kennedy, GeoPraxis president and CTO. "The incorporation of our connectors by the major BIM and CAD vendors enables the Green Building Studio Web service to use the wealth of information in the early design stage models. It creates a geometrically correct, equivalent thermal energy model and provides almost immediate feedback on the energy implications of architectural design scenarios."

Running the Energy Analysis
Using traditional CAD systems, energy analysis can be a painful process. If it's a 2D system, engineers must create special 3D analysis models or manual plan take-offs from the floor plans. If it's a 3D system, they must extract building data from disparate CAD files, then merge it into a single input file. In most cases, they must massage the data for analysis import and then translate the output for the designer's consumption.

Now, using Autodesk Revit and Green Building Studio, the process is simple. When you initially register for Green Building Studio Web service, you download a 270KB Green Building Studio client. You use the client to connect to Green Building Studio so that it can analyze your buildings.

Each time you run an analysis, simply make sure that the rooms in your design all have room numbers -- the unique space ID used in the analysis programs -- and that the model has a defined project type and address for determining building codes, local climate

Figure 1. The Green Building Studio Web service uses building information from Autodesk Revit to perform fast, accurate energy analysis on early-stage building designs.

information, and so forth. On the File menu, click Export, select the file type, and save the export file to your hard drive. Then launch Green Building Studio, submit the data for analysis, and within minutes view the results of the energy analysis via your Internet browser (figure 1). The results provide energy statistics for your project and recommendations for improving your design based on local standards for building type, climate, and other considerations. You then can modify your building design and repeat the process to see what impact a design change has on the building's energy efficiency.

This simple process belies the enormous computational power behind it. Green Building Studio calls on a large network of relational databases that contain hourly weather data, design data, and regionally relevant libraries of default building characteristics with common energy code baselines. The system can even recommend building products appropriate for your building, greatly simplifying the early specification process.

Win-Win Results
Using the Green Building Studio Web service and data from building information models lowers the significant cost barrier to green building design. More accurate energy analysis leads to a more efficient building design and lower operating costs for the owner. And it lets architects perform these functions in-house, which makes sustainable design services more affordable for the client and increases profit for the architectural firm. Building information modeling is a win-win proposition for everyone.