Posts Tagged ‘design

27
Jun
08

BIM Revolution Not Quite Here Yet

An interesting article in The Economist suggests that the revolution in BIM (Building Information Modeling) is, at least for the present, mainly wishful thinking. By and large,

… fancy graphics tend to be used only for conceptual purposes and play no role in the detailed design and construction of the finished structure. For the most part, this is still carried out with old-fashioned two-dimensional elevation and plan drawings, created by hand or using computer-aided design (CAD) software. “It’s still a 2-D profession,” says Shane Burger, an associate architect at Grimshaw…

With CAD, you draw your picture, and the software makes it malleable, so it can be changed, added to, combined with another. With BIM, you put in the facts of the case and tell the software what you need, and it draws the picture. It seems that many practitioners are still in a CAD headspace, unable to make the leap of imagination that would really put BIM to work for them.

When the client says, “How will it look from over there?”, the elegant and stunning pictorial answer can be shown, and that’s cool. But there’s so much more to BIM than dazzling graphics. The amazing virtual walk-through is negligible compared to the real power and beauty of BIM. The thing to keep in mind is that a building information model is a digital representation of both the physicals and functional characteristics.

Traditionally, one of the embarrassing possibilities, once construction starts, is discovering that a basic law of physics is being violated, as two things, such as an air duct and a beam, try to occupy the same space at the same time. In building information modeling, the word “information” is there for a reason – because the best part of BIM is the huge database of everything you could possibly want to know about every part of the building at all times. Like the weather or any other system, a building is subject to the so-called “butterfly effect.” Tweak something over here, and something over there is affected. With BIM,

the model is based on objects, which are solid shapes or voids with their own properties. The model also includes information about the relationships between these objects, so that when one object is changed… any related objects are automatically updated.

In a large project, the number of stakeholders can grow to monstrous proportions, and BIM keeps them all on the same page. Time is an added dimension, so processes can be followed through the life cycle of the building. All the stages of design, construction, and facility management are taken into account and automatically updated. Energy use, lighting, heat flow, acoustics, and many other factors can all be kept track of. The most important thing is the sharing of resources and information across platforms and environments.

The author points out that the early adapters are the more flamboyant, high-name-recognition architects. Because their creations are so complicated and unusual, there’s really no other choice. What’s needed is BIM across the board; it needs to be a plow horse as well as a show pony. Apparently this is happening, as the General Services Administration now requires BIM technology for all the projects it funds.

Of course, accurate cost estimation is a huge incentive, now more than ever. When the digital prototype is the main reference, it’s possible to calculate very finely the quantities of materials needed. Perhaps even more important, every detail necessary for compliance with regulations is spelled out. MIT professor William Mitchell estimates that inconsistencies and clashes can eat up from 2 to 5% of a budget. This is interesting, because that’s about the same percentage range as it costs to make a really good green building. So, thanks to BIM, it seems that a building could be made greener (costing 3% more) and smarter (saving 3%) and still end up with about the same price tag, when all’s said and done. With the cost of energy and materials going up, and the cost of information going down, it looks like the BIM revolution will go forward.

Pictured: the Eden Project, in England. The geodesic domes were BIM-designed.

SOURCE: ” From blueprint to database ” 06/05/08
photo courtesy of just_laze , used under this Creative Commons license

16
May
08

The Cladding of Porter House, New York City

Porter House

In Manhattan’s meatpacking district, an existing warehouse needed an extra 15,000 square feet for a housing addition. The job was done by Sharples Holden Pasquarelli (SHoP) who, as described in the Computing Technologies section of Architectural Graphic Standards, 11th Edition came up with a “custom-designed, laser-etched zinc metal wall panel cladding system…The condominium’s zinc rainscreen emerges from a family of 15 profile types, from which there are 150 versions of profiles, yielding 4000 total panels.”

The variations were achieved by cutting and bending each profile type of panel differently. After four initial drawings, the rest of the communication between SHoP and the fabricators was carried out electronically.

This case study is presented in order to explore the use of software by SHoP in design, construction, and fabrication. It entailed a lot of originality, all of it concentrated in the few-inches-deep cladding system, with the other parts of the project achieved more conventionally. Part of the reason for this concentration on the outer layer was to astonish the eye, because making a visual impact was a priority. The creators were going for an ambiance of complexity and randomness, to fit in with the existing environment. This aim was also achieved by offset from the underlying warehouse. The addition looks like it grew there.

The use of building information modeling achieved huge gains in fabrication and installation time, accuracy in the production of the varying panel elements, and efficiency of material use. The builders were able to get the most bang for the buck out of standard zinc sheets of 39″ by 118″, by careful planning of how the various sized pieces would be obtained, cutting waste to the bone. They started with several basic shapes: flat panel, bent sill panel, window panel, light box panel, and more.

To deal with the numerous idiosyncratic factors that needed to be taken into consideration, ShoP used the 3D NURBS program Rhinoceros, which told them what shape to make each piece in order to meet the technical requirements of a rainscreen. Enthusiasts describe Rhino as very simple and powerful, able to do all levels of design for any discipline, and blessed with a high degree of interoperability. The program is said to be especially popular in Europe.

Rhino describes itself as having the capability to do uninhibited free-form 3-D modeling with extreme precision. It can create, edit, analyze, document, render, animate and translate NURBS curves, surfaces and solids, handle polygon meshes and point clouds, and support a wide variety of 3-D digitizing arms, 3-D scanners, and 3-D printers. It can handle large projects, and has the additional advantages of relative ease in learning and relative affordability. It can, in short, do everything but sing lullabies to the kids in a finished building’s daycare center.

After Rhino had done its bit for ShoP and the Porter House, everything was transferred to a program called Solidworks to fine-tune the 150 different panel shapes. For a short description of Solidworks, we turn to Architectural Graphic Standards, 11th Edition, which says on page 937:

Solidworks is most commonly used by mechanical engineers, industrial engineers, and product designers. By building “solid models” of objects (as opposed to surface models), engineers can perform finite material and structural analyses on objects, as well as communicate more seamlessly with CAM equipment, which often operates on proprietary software that more easily reads solid models.

Please feel free to share experiences other projects have had with Rhinoceros and Solidworks.

SOURCE: ” Computing Technologies ” 2007
photo courtesy of b.frahm , used under this Creative Commons license