Wednesday, November 30, 2005

A Good Article (2)

BIM software is not PM software. Parametric Modeling is great. And, so is Building Information Modeling. Unless you ask Ken Sanders, AIA. As has been our theme this week, the really good journalism out there explains the difference.

"Art, like morality, consists in drawing the line somewhere." - G. K. Chesterton (before 1936)

“Ten years from now we will be having a drink and laughing about how we used to draw in two dimensions and delivering sheets of paper.” Carl Galioto, Partner - SOM New York (2005)


Blogger Norman Blogster said...

I couldn't fail to disagree with you less.
Parametric modelling is just a subset of Building Information Modelling.
Revit was actually written by a group of programmers who came from PTC (Parametric Technology Corp) - the guys who write Pro Engineer, an extremely successful CAD app for car manufacturers etc. So these programmers had an idea by the water cooler one day, thinking they could apply the same technology to the wonderful world of architecture, seeing as the car world was saturated and architects are loaded (yeah - right!). So they formed a company called "Charles River Software" in 1997, wrote the beginnings of Revit and sold it to the big A in 2002 for a cool $133m. I don't actually know Revit, but I think it's as good as BIM gets from what I've heard. Certainly, ArchiCAD tries but fails due to lack of intelligence. But how can you have Building Information modelled without parameters? BIM is just PM with bells on applied to architecture. The theory is it lets you take the components you've inserted (parametrically defined, of course) to build the building, and then manage its construction process.
This idea has been around since the early days of CAD. We had a system called GABLE at Sheffield University in the '80's. What a dog! But the idea was bang on.
In 10 years time, we'll be no closer to the dream of building virtual lego buildings, pressing the button and getting the contractors to build the real thing. Why? Because the industry's culture has to change first. I don't know about the US, but in the UK, the industry is practically agricultural in its conservatism and resistance to change. The contracts between the contractors and the architects are also very adversarial. The car manufacturers own their supply chain, which they can achieve because they build gazillions of cars all the same. Because of this, it makes business sense to develop their own CAD systems, or work closely with the vendors, as it costs megabucks. Same in the aerospace industry. Most buildings are built only once - so they are all prototypes! And the team who build them (design team & contractors) are not really a team, as they're always fighting about how much it costs, whose fault this or that is and how best to build it while keeping it cheap. PLUS! The design process doesn't work that way. There's always a rush to get the building finished and it's never designed to the nth degree before it starts on site. In fact, most details aren't even considered until the contractor is there with his hammer in hand, waiting to know what to do.
Oh, you do know how to get me started!
So in theory, it's great. The CAAD software vendors can't understand why the industry doesn't adopt it. But life's just not that simple, and neither is architecture.
Better to be an accountant.

9:00 AM  
Blogger J said...

Thank you for your comments. I am humbled by your experience with architectural design tools, and your knowledge of their development. Your points are welcomed and well taken.

However artificial as your perspective makes the line I’m trying to draw, I still might point out the design-implications a division between BIM and PM tools.

Currently, BIM software helps designers model an architectural artifact from a construction standpoint. Tools like Revit come with libraries of building materials and other "components" that are dropped in place and whose positions are modeled by determining positional relationships. For example, out of the box, one can use Revit define a 50'-0" brick and CMU wall going NE from an origin, then attach a 48"x36” Marvin wooden casement window, whose sill is 3'-0" off the ground and whose center is 10'-6" from the NE corner. Here, your point is taken, that these certainly are design parameters, and so one could certainly argue that the designer is truly engaging in parametric modeling.

It's my observation that PM software helps current architects get to more rudimentary design decisions. When one works in Generative Components (admittedly only now about to go Beta), the design pallet begins with points, lines, splines, nurbz surfaces, and user coordinate systems. Those versed in computer science will recognize that he first effort in PM tends to be to define classes, larger "components" that are then combined according to relationships that the designer defines. For example, in this design, this design, and this design the authors can affect local “component” design decisions based on global geometries. The arrangements are expensive to fabricate for the same reason that this is a more technically engaged design. The PM design process creates highly unique configurations because it blurs definitions of components and arrangements.

Respectfully, the value of the distinction lies in your very complaint, Mr. Blogger. By discarding the conventions inherent in BIM software, the PM software is the forum for design decisions of wider latitude and freedom. You'll notice PM is the refuge of designers who choose to work in splines and nurbz surfaces to create wildly complex and unconventional forms. In contrast current BIM software tends to leverage assumptions about building materials and components to help deliver buildings faster and with the illusion of more control.

Programs like Catia definitely blur that line.

Your comment certainly points out that at a rudimentary level these software packages are turning the focus on arrangement. This is a blessing to designers, who constantly struggle to define what it is they deliver.

There is wisdom in agreeing that PM is best placed as a subset of BIM modeling. But then perhaps the reverse isn’t more accurate? It might depend on how you frame the question.

It’s so true that the culture of building delivery stands reticently against embracing the product of BIM and PM modeling. Perhaps in 10 years there will be two cultures of building, technically savvy technocrats and died-in-the-wool hammer swingers. There are advantages to both.

This discussion is based on wide generalizations. Hopefully shared definitions can help us talk on the same wavelength. I truly enjoyed your comments because they have forced me to struggle to define what I mean, and your comments have shaped that definition.

7:10 PM  
Blogger Norman Blogster said...

Just filling a rainy lunchtime ;)
Link this discussion with the GA discussion above and you've got an interesting research direction, wouldn't you think? i.e. breeding buildings in a primordial soup of BIM components. Just the fitness function to define then (he says like it's a simple thing). The environment could then start to have an effect on the building itself, something which all great architecture should achieve.
Oh, if only I were a student again!
Keep up the blog - I'm enjoying your thought provocation & topics...

12:53 AM  

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