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BAA has set itself the target of using technology to cut 10% off the cost of Heathrow Terminal 5. It is doing this by getting the whole project team to use a single 3D computer model to design, build and ultimately maintain the terminal building.

Such massive savings are there to be made because the conventional system of having lots of designer teams working in isolation on their own sections of the building is grossly inefficient. Conventionally, the architect designs the building and passes the CAD drawings over to the engineer. The engineer then draws the building all over again for the engineering analysis, as do the subcontractors, and the result is that the building and the elements within it are redrawn hundreds of times. BAA has proved in its research into the construction process that by the time the project gets to site these drawings are bound to contain inconsistencies, meaning that different parts of it don鈥檛 fit together and have to be reworked on site. The estimated cost of wasted time and materials alone is at least 10% of total project cost. If the costs of the disruption to the programme are factored in, the figure is even higher.

鈥淭he idea behind the single project model is to derive an unambiguous set of data through the sharing of data,鈥� says Mervyn Richards, LaingO鈥橰ourke鈥檚 CAD technology manager, who is spearheading this project. 鈥淲ith this, the engineer never redraws the information; they reuse the architect鈥檚 data and add to it. We are getting everyone to work on the same data-set to drive out error and improve efficiency.鈥�

A 3D model incorporating intelligent object technology is being used at T5 to improve efficiency even more. This means objects in the CAD drawing 鈥渒now鈥� what they are, and how they fit with other objects in the building.

The massive roof nodes connecting the roof structure together are a good example of how the single-model environment works . Richard Rogers Partnership designed the node and passed it over to structural engineer Arup. The engineer used the architect鈥檚 drawing to carry out the structural analysis. RRP then modified the design to fit the analytical requirements using the same set of data. The model was passed to steel fabricator Rowen Structures who use it to fine-tune the design of the parts of the node that had to be specially made. Finally they used the model to control the machinery that made the roof parts.

Information contained in the model will be used to plan the methodology of constructing the building, to manage time, and to to improve health and safety 鈥� even to plan retailers鈥� fit-outs. And anyone can use the model without specialised CAD knowledge, as it can be seen using a common 3D viewer called NavisWorks.

The model will also help BAA to make savings on maintenance and improve its knowledge base for future projects. 鈥淲e need to tie the model into the facilities management systems so that if, for example, you find a series of valves that keep failing, you can change the specification on the next project,鈥� says Andrew Mannington, BAA鈥檚 CAD manager.

It requires discipline to make the single model work. Everyone who contributes to it has to follow the same rules. 鈥淲e have had to lay down a series of protocols that says how data is generated, managed and moved around,鈥� says Laing O鈥橰ourke鈥檚 Richards.

This includes getting team members to ensure CAD data is dimensionally correct and is produced at full size to the same co-ordinates. There are conventions for naming different parts of the drawing, and data exchange is carefully managed. Clash detection software is used to check that everyone has stuck to the procedures. Richards says that if there is a lapse, the reason can be identified and, if necessary, further training given.

For an example of how the intelligent object technology streamlines the design process, consider the terminal鈥檚 M&E chimneys. These are giant, self-contained service units dotted around the building. When the engineer specifies a pipe for them, they say what it needs to be made from, its diameter and its lining. The software automatically chooses a suitable example from a library of specification-driven intelligent objects. Once the building is finished, the FM teams will be able to click on that object on the CAD drawing, find out its attributes, and use this information to service or replace it.

Richards sees the model evolving to take advantages of advances in technology acceptance. For example, manufacturers could post their products on their websites as intelligent objects. These could be procured electronically and downloaded into the model. 鈥淭his is another dimension we are beginning to explore,鈥� says Richards.

Lessons learned at T5 are being disseminated to the rest of industry. The Construction Project Information Committee has published the Code of Practice for Production Information, which contains the processes and protocols used at T5. And people do not need to be working in the heady world of 3D modelling to benefit from it, as the code is aimed at the 2D majority 鈥� with the idea that it will make it easier for them to make the leap to 3D.

Meanwhile, the government is doing its bit by investing 拢750,000 in a Partners in Innovation project to promote collaborative working. The project will be largely based on the lessons learned at T5 and will include the CPIC code.

Another significant development is the International Alliance for Interoperability鈥檚 success in getting the International Standards Organisation to endorse its standard objects, the 鈥淚ndustry Foundation Classes鈥�, accepted as an international standard. Furthermore it has just published its IFC 2 脳 2 standard, which extends the range of objects covered by IFCs and the range of parameters each object possesses. Finally, most of the big CAD vendors have thrown their weight behind IFCs, which means their adoption going to be a much more practical proposition.