Quicker on the draw

The same design and technical problems raise their heads again and again in building design. Much of what engineers do is a variation on their last work. Similarly, the problems being solved in one design office are simultaneously being dealt with in a hundred other offices by engineers working on similar projects. In short, there is an enormous duplication of effort.

By providing common, agreed solutions for some of these problems, the efficiency of drawing production can be improved, best practice solutions are more likely to be implemented, and there will be fewer site hold-ups for clarification. There should also be more time for innovation and opportunities for prefabrication.

For these reasons, the BSRIA (with DETR-funding under the Partners in Innovation scheme and industrial funding from companies in the design, installation and manufacturing sectors) is forming a central library of standard details. This library of drawings will be centrally maintained by BSRIA and made available to designers and installers.

The aim is not to produce regulations stating "this is how you must do it". Rather, it is to provide drawings that cover common situations that engineers can use if they wish. There is no reason why drawings shouldn't be modified or adapted to suit individual situations. The real aim is to prevent engineers starting from a blank sheet of paper and spending a lot of time finding a solution that may not necessarily work very well.

The project has been running for about two years and has a further eight months to go. To date around 300 drawings have been identified as worthy of inclusion and are in various stages of development. The project was organised by three main editorial committees – one each for pipework, ductwork and electrical issues. These committees have met regularly to propose drawings, comment on existing drawings and help with the preparation of new drawings.

Basic rules for the library

A number of basic rules were laid down at the outset. First, individual drawings should be A4 landscape and AutoCAD compatible. Second, each drawing should contain information explaining the purpose and function of features. This is to avoid the problem of reviewing the drawing in the future and not knowing why certain features have been shown. Drawings should be also be layered to a recognised convention.

It was also essential for the library to show as wide as possible selection of alternative solutions. This recognises the individual preferences of engineers and that different solutions might be appropriate for different types of project. Also, as part of the library's intention is to promote innovation, the drawings must include some of the more innovative solutions on the market and not merely represent more familiar products.

One of the pipework committee's main tasks was to develop a set of interchangeable schematic solutions that can be used to tailor a schematic drawing for any project. The drawings start from small combinations of components such as commissioning valves, flow measurement devices and isolating valves. They subsequently build up to include different terminal connections, branch connections, secondary circuit and primarily circuit connections. The drawings have been scaled so that they can be easily bolted together within a computer aided design system and finally rescaled to suit the drawing size.

The ductwork committee had to deal with many more installation than design issues. One such issue it had to grapple with was the installation of fire dampers, as some of the certified methods are simply not practical on construction sites.

In particular, the procedure for fixing back of fire damper lugs to reinforcing bars. In conjunction with the HVCA Ductwork Group and the HEVAC Fire Damper Manufacturers Committee, a set of fire damper installation details have been developed. These show a feasible methodology for installing dampers and for which, it is hoped, the approval of a recognised test laboratory can be given.

The electrical library

On the electrical side, the emphasis has been on the problem of symbols and the preparing of schematic wiring diagrams. Existing practices tend to develop their own electrical symbols because the published sets offered by British Standards and others are often not appropriate for detailed electrical drawings. On top of this, they may not be up-to-date with the range of products and electrical components which might be installed in modern buildings.

As a consequence, a complete set of standard symbols is being prepared – based on the best of what is currently used. Once complete, these symbols will be used to form standard groups of components that can be bolted together to form schematic drawings in the same way as the pipework schematics.

Once the library is completed (planned for August 2000), the challenge will be to maintain and expand it so that it remains a comprehensive up-to-date facility. This can only be achieved in the long-term by the generation of additional funding, so it is important that the initial library is successful enough to attract ongoing subscribers to the service. This way, it will become a self-funding operation.

Once established and in use, it is anticipated that engineers will feedback their own ideas and solutions for different design and installation problems, which can be added to the library. The library will then have achieved its aim: providing a valuable central information source and a mechanism for improving the performance of companies and the quality of their output.