A Change of Plans
Hurrah for today’s new generation of CAD programs. With them, architects and contractors can design marquee buildings more accurately than with conventional means. So how come everyone isn’t jumping on board?
by Malwina Gudowska
As you drive by Calgary’s Sixth Avenue where the much anticipated 58-storey EnCana Corporation office tower, the Bow, will be located, there’s nothing more to see than a large hole in the ground. Sure, there’s some action happening down below, but much to the chagrin of many businesses, pedestrians and drivers, the construction looks like it is in premature stages. But, even so, already vast quantities of steel are arriving fully fabricated and ready to be assembled for when the building does emerge. Either the estimated 2011 completion will happen much earlier (to the pleasure of those aforementioned businesses, pedestrians and drivers) or someone from the contractor’s office was ballsy enough to fabricate all the materials way ahead of time.
If you wished for the former but guessed the latter, you’re correct. The increased confidence of design teams is a result of new modelling software, Building Information Management (BIM), that allows architects to see finished projects, complete with bolts and screws, long before the actual construction begins. “That whole manufacturing process could have never been implemented so quickly without front-end collaboration,” says Stephen Carruthers, partner and director of western offices for Zeidler Partnership Architects, the firm chosen as the executive architects of the Bow in collaboration with Foster + Partners.
The adoption of a single, integrated platform that allows users to ideate, conceive, explore, document, fabricate and even manage a project has gained momentum over the past few years. BIM contains complete information for all of the stages of design and building processes. The software uses digital information to create more accurate 3-D models and, in turn, reduces expenses, errors and time. The result is better communication between architects, engineers and other consultants because the model can be shared between all professionals involved, and the completed version of a project is seen on a computer screen long before it is actually built.
BIM is an umbrella concept under which there are many different software versions, including the most commonly used Revit by Autodesk, Digital Project by Gehry Technologies, Bentley Architecture from Bentley Systems and Graphisoft’s ArchiCAD, in addition to many others.
Although BIM has been popular with more elaborate projects like New York’s Freedom Tower or Frank Gehry’s Disney Concert Hall, the technology is leaking heavily into more normative practices and into the offices of architects that aren’t necessarily dealing with the intricacy of curved walls. And that’s because it offers many rewards.
One of BIM’s advantages is the ease with which information can be adjusted throughout the entire project. For example, rather than adjusting each part of a building because of the addition of, let’s say, a door, the repercussions of that one modification can instantaneously be seen throughout the design. It can identify quantities and the price of materials, eliminating errors as well as saving time in the construction process.
Virtual modelling greatly reduces information loss when it is handed from architect to construction consultant to client.
“We used BIM extensively on the curtain wall and on the steel structure of the Bow and that has been a terrific assist to get us from A to B more quickly,” says Carruthers, who adds that the Bow could have not been designed without BIM. “Because of the curve in the Bow, there isn’t anything that is actually similar anywhere along that perimeter wall…the model is critically important to actually understanding the space you are truly inhabiting on each floor.”
There are as just as many challenges to adopting BIM software as there are promises. Zeidler Partnership Architects implemented Autodesk’s Revit in 2005, approximately a year and a half
before becoming the executive architects on the Bow. A former Autodesk employee was hired full time to provide in-house training and technical support to ensure a smooth transition. “You leap into it and you hope you put all the provisions in place that will see you through to the other side,” says Carruthers. “It’s very expensive and it’s very risky, particularly with a high-risk, high-liability project like the Bow.”
According to David Jefferies, principal at Zeidler Partnership Architects and managing project architect for the Bow, the firm’s investment in BIM, including program costs, upgrades, training and support for Revit runs somewhere between $500,000 and $750,000 to date. In addition to the initial cost of approximately $6,000 for one Revit seat, followed by a yearly subscription that includes support and product updates, there’s extensive training. Without any basic familiarity, the production cycle can initially slow down before it speeds up.
For some firms, especially small- to medium-sized ones, it’s a high-risk proposition to commit to BIM at this stage. “If you’re the first one doing it, it will be astronomical, but in five years…” says Calgary architect Marc Boutin, who runs his own small practice. Boutin’s firm will eventually make the shift but isn’t there yet, partly because it’s hard to specialize in a smaller market like Calgary. Companies like Boutin’s stay afloat by choosing a diversity of projects including urban design planning, architecture for cultural institutions and custom homes.
So what about AutoCAD? In normative practices, AutoCAD remains the standard, stresses Boutin, who is also an associate professor of architecture at the University of Calgary where AutoCAD is still taught. AutoCAD was first released in the early 1980s and is a computer-aided design (CAD) software application for both 2-D and 3-D drafting and design. It was developed by Autodesk and was one of the first CAD programs to run on personal computers. CAD has been used in architecture, design and engineering for the past couple of decades, and AutoCAD has become an industry standard for most architects and designers. Although 3-D drawings can be produced in AutoCAD, the program lacks the intelligence of BIM.
BIM creates a building representation while CAD creates only a geometric representation. Even though a 3-D solid model is on the screen, the CAD program cannot determine one line from another. Where the user sees a window, the program only identifies it as a line. In BIM, the program recognizes walls as walls and windows as windows and the user can add properties such as insulation to the walls right then and there. As buildings become more and more complex, CAD does not have the power or the intelligence to resolve issues in advance – for example, making sure all mechanical systems are in the right place when dealing with complex curves and innovative design. Although new versions of AutoCAD are released yearly, they have little in the way of new features and are still lacking the capabilities that BIM offers.
Pages: 1 2
Follow Alberta Venture On: