Sustainability CAD Strategies
Jay Bhatt, vice president of Autodesk AEC Solutions, summarized the tone of the conference when he said the building industry must "meet society's need for growth in an environmentally responsible way."
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Connecting BIM with Green
Illustrating the importance of both sustainable design and BIM was a presentation given by Patrick MacLeamy, CEO of HOK, who gave a broad overview of the 52-year-old firm and its vision. In its 25 offices around the world, HOK maintains knowledge specialists who are expert in specific building types such as hospitals, airports, and stadiums. They must be ready to apply that expertise anywhere in the world.
Within the last 40 years, the building industry has declined in productivity, said MacLeamy, and lack of collaboration in design and construction is largely responsible. Perhaps there is something to be learned from the manufacturing, automotive, and aircraft industries, about how we could retool the building industry to make it more efficient. The challenge is to build custom "products" with the efficiencies that may be found in mass production.
Bhatt also drew parallels with the manufacturing industry, which has for years successfully applied modeling technology, analysis and forecasting, collaboration, and supply chain management. He noted that those same technologies may be applicable to sustainable design for reducing waste and inefficiencies and for analyzing various types of loads and stresses on buildings.
MacLeamy explained that having a centralized view of a design project, as is provided by BIM, all the way through design and construction, is revolutionizing the way information is shared. In moving from a 2D drawing-based approach to an integrated model approach using Revit, HOK has changed the way it staffs projects and has shifted work around to accommodate the changes in the design process.
Among the priorities of the firm are sustainable design and "building smart," defined as the combination of BIM and integrated practice. Integrated practice is a term coined by the American Institute of Architects which defines a cooperative relationship between owner, contractor, and subcontractors.
"Our goal is clearly to use our BIM to understand things like energy use as well as resource consumption and other sustainability issues early on in the design process so we have the opportunity to change them before it's too late," explained Mario Guttman, firmwide CAD director for HOK, in a later interview.
For the 100 or so BIM projects that HOK can have going on at one time, there is strong pressure from clients to make them sustainable. "We believe buildings can consume far less energy and have smaller carbon footprints," declared MacLeamy, "We're on our way to building zero-energy consuming buildings." Another advantage to clients is that owners of zero-energy buildings can lease sustainable spaces at higher rates.
Some HOK projects start with a sustainable energy specialist exploring alternative approaches to the building design that may explore different building forms, for instance, or passive ventilation systems. At that point in preliminary design, Guttman pointed out: "We may be doing energy modeling but we haven't really done any architectural modeling. So in that sense, the energy model becomes the driver of the BIM, and we take forms out of the energy model and use them to begin to generate the architecture."
Sustainability can inform design not only in overall massing but through design components as well. Features such as wind scoops or shading canopies can become interesting design elements.
As a firm's design processes evolve, by incorporating sustainability earlier, for instance, and by developing building information models, other processes like energy analysis and cost estimates can become more closely integrated with schematic design. "The process of design is becoming more of an information management process and perhaps less of a drawing process as we used to think of it," noted Guttman.
Innovation in New Orleans
The increasing demands of changing weather patterns and natural disasters are also shaping architectural design. An extraordinary project created with Autodesk software, by brothers Peter and Mark Anderson of Anderson Anderson Architecture, proposes high-density housing for a riverfront site in New Orleans.
The Andersons's design, Camel Back Shotgun Sponge Garden, took top prize in an international design competition sponsored by Architectural Record and Tulane University. Entries in the competition, "After the Flood, Built on Higher Ground," was featured as part of La Biennale di Venezia's 2006 Cities, Architecture and Society exhibit.
The Andersons's innovative design, incorporating sustainable, unorthodox materials, was crafted to protect and enhance the environment and structures. The "sponge garden" incorporates living roofs that will absorb rain water — as does the skin of the building — that is then funneled, filtered by plants, stored in rain barrels, and made usable as drinking water in the event of future flooding in the New Orleans region.
What is more, there is a line of alluvial sponge combs that rest side by side between the riverfront and the buildings. When the river is at a normal level, the sponges trap sediment deposited by the tides, which will help raise the ground level of the shore and provide a habitat for invertebrates and other creatures. When the river rises, the sponges fill with water and form a barrier to keep the river from overflowing onto the complex.
The building itself will be fabricated largely offsite using a "hybrid, steel-frame/ structural insulated panel system" that will contain no water-absorbent construction materials or internal cavities. The building units themselves will be manufactured and made of water- and termite-resistant composite concrete panels.
As part of World Press Day 2007, David Mills, technical marketing manager of AEC Solutions, outlined some of the new features of Revit. In support of BIM, and to improve its application to large projects, refinements have been made in the user's ability to apply selective edits to repetitive elements, to link files, to separate subsets for work sharing, and to incorporate a rendering system for quick visualizations.
Revit Architecture 2008, expected to be released in April 2007, will include new sustainable design features such as analysis of materials, quantities, energy use, and lighting. With enhanced gbXML (Green Building Extensible Markup Language) functionality, designers can quickly perform energy analysis and study building performance using tools such as those from Green Building Studio, Inc. and the Illuminating Engineering Society (IES).
It is hoped that the creation and use of coordinated, internally consistent, computable information about a building project in design and construction will assist in the drive toward universal sustainability.
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Susan Smith is the editor of AECCafe, an online news portal for the architecture, engineering, and construction industry, as well as GISCafe and GISWeekly, an online portal and weekly magazine for the geographic information systems industry. She has been writing about architecture and technology for over 15 years and resides in Santa Fe, New Mexico.
Daylighting analysis, integrated with computer-aided design software in the IES Virtual Environment.
Image: Courtesy Autodesk
Dynamic Thermal analysis.
Image: Courtesy Autodesk
Sendai (Japan) International Airport, by HOK.
Photo: Yukio Futagawa
Camel Back Shotgun Sponge Garden, sustainable 160-unit housing project for a riverfront site in New Orleans by Anderson Anderson Architecture.
Image: Anderson Anderson Architecture
For the Camel Back Shotgun Sponge Garden: a line of alluvial sponge combs between the riverfront and the buildings.
Image: Anderson Anderson Architecture
Hong Kong Stadium, by HOK.
Photo: Kerun Ip
Telstra Stadium in Sydney, Australia, by HOK.
Photo: Patrick Bingham-Hall
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