Plugging In Prefab
Fabrication of the bathroom pod steel cages took place at Ayrshire Metal Products in Scotland. These were then shipped by truck to a shed in Milton Keynes, where they were fitted out with plumbing, electrical, fixtures, gypsum board, and tiling.
Meanwhile, wall panels and floor cassettes were made at Ayrshire, and large-scale, hot-rolled steel elements were welded at Littlehampton Welding. These steel elements included balconies, hollow-section columns, three-story elevator shaft sections, and prefabricated stair runs.
Delivery of the off-site fabricated structural elements to the site was carefully orchestrated in accordance with minimum site storage space and the complex erection sequence. The 16-bay building was erected vertically in three bay lifts. This enabled first-fix crews to keep moving while second-fix crews were able to follow behind in parallel. The building was then finished off with conventional site construction.
The project was brought in ahead of schedule and under the established budget. It won a Royal Institute of British Architects (RIBA) Housing Design Award in 2001.
Modeling the Parts
"Lots of renderings look terrific but fail to show what a building is made of, Hardiman says. "In order to focus on what was really important, we decided to model only two bays of the building. We also showed it in a halfway assembled state. This enabled us to present at least one of each major component very clearly. Its prefabricated nature was readable with a casual glance. Beyond the actual project, it became, for a while, symbolic of progressive construction thinking."
Hardiman notes how the power of visualization and its ability to communicate design intentions clearly have played an important role in the development of new building techniques. "It's hard, from where we are now, to imagine engaging in the process of design without the benefit of 3D modeling. Prefabrication requires that everybody in the supply chain clearly understand the components and the process of putting them together. You can attempt this with plans and sections but it's such an expenditure of energy for so little gain."
While Hardiman sees benefits in a number of available modeling programs, he sees form-Z as having some powerful advantages when it comes to architecture. In particular, he attributes his affinity for form-Z to the ability to precisely control dimensions, to the object and grouping controls, to the architectural shape tools, and to its ability to export files in many different formats.
As for the future of 3D modeling within the field of off-site fabrication, he envisions software developments that integrate more detail-oriented information along with continued growth of modeling and rendering capabilities.
Hardiman says: "I think the moment will come soon when the representation of time and how things actually go together is expected to be shown in virtual form before going on-site. Any problem you can resolve before getting to the site (or to the factory for that matter) is going to help save money in the building process, and dynamic movies of components going together can help this tremendously.
"So I think that the ability to animate individual components is very important. It would be very useful if each component could be linked to a database, showing everything about that component (part number, whereabouts, cost, manufacturer), as they have been doing in the airplane and automotive industries for years."
Now working in Boston, Hardiman continues to use computer modeling tools to explore off-site fabrication systems for New England's residential housing market. He concludes: "It would be fantastic to come up with a residential building system that is truly exciting, that is very sustainable, that is extremely flexible, and that can really make a leap in the 'easy-to-build' department. And it would be great to reap the economic benefits of this."
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Bill Jordan is editor of In-form-Z, a publication of auto-des-sys, Inc. This article first appeared in the 2005 issue of In-form-Z and is reprinted here with permission.