• Field Notes 25.10.2011

    Frank Gehry (designer of curvilinear buildings that are more sculptural than architectural) has put together a group of architects to address 3-D building issues from an architect’s perspective. Does this mean the architectural community isn’t getting what it wants from current software packages, so has to create its own? And what does this mean for the glazing industry?

    Gehry’s architectural business has been so successful with the use of Catia software in modeling his free-form designs that he started a side business, Gehry Technologies, which initially extended Catia to architectural applications.

    He now appears to be going a step further, given the impressive list of architects he’s assembled. It seems he’s looking for tools that are more open and responsive to the design side of the building industry, rather than the construction side, which is where Revit is strongest. Hopefully they can merge the best of both worlds.

    One reason this stood out for me is we’re currently working on a bid with a highly detailed, blast and high wind requirement curtain wall project for the government. In putting together the shop drawing proposal, and in getting proposals from 3rd party vendors for their shop drawings, the question was posed, “Can we get access to the CAD versions of the architectural drawings?”

    The reasons are pretty straight forward: elevations, floor plans, building sections, etc. would be simpler to draw as opposed to starting from scratch. It would save significant time in drafting these if the architectural drawings or models were made available – at least as a basis to review and/or revise to fit the project specifics.

    When we’ve requested such drawings in the past, the architects aren’t crazy about letting those out unless a waiver is signed agreeing to “use them at your own risk.” Many companies will sign the waiver, agreeing that to do so still puts the engineering efforts one leg up. I agree.

    There have been times when the architectural CAD files needed to be revised – that accuracy of say mullion locations was decimal points off (for example, mullions were located at 59.95 inches, but the dimensions said they were at 5 feet-0 inch on center). If the horizontals were cut to the 59.95 inches dimension as opposed to the 60 inches dimension, they’re 1/16 inch off, and after more than 5 or 6 modules that starts to add up.

    The more accurate the CAD drawings, obviously the more accurate the subsequent documents can be. One of the things CAD can do for or against you is the GIGO syndrome: if the info going in is garbage, the info coming out is garbage, too. Accuracy is always best in the computer world. If you don’t believe me, put an extra grand in your electronic checkbook and see what happens.

    Overwriting dimensions, or spacing things to look pretty in CAD, shorts its capacity to accurately model the conditions that eventually will be built. One argument is that you don’t need to be that accurate, that 59.95 inches is close enough to 60 inches to not cause any serious problems. But after a while, doesn’t the lack of precision catch up to you? Incorrect takeoffs, mis-installation of components in the field, and other impacts could happen that otherwise would be avoided if the drawings are accurate.

    I’d be interested in any of your stories, pro/con, with using architectural CAD files on projects. What’s been your experience?

    For the time being, what’s the Latin expression, “Caveat Emptor?” Let the user beware, unless the architects are willing to go on record that there are no errors in the drawings. Yeah, that’s not likely or realistic, is it? The Eagles will WIN the Super Bowl first…

    Hopefully the Rangers pull out Game 7 Wednesday night. Lord knows the Eagles need to win Sunday, too. You can’t have it all your way, Dallas!


    Posted by Blogger @ 8:15 pm

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