Select, size, locate

Standard solutions have the potential to provide benefits throughout the supply chain, reducing design time and cutting both construction and operating costs. Reductions in design time can be magnified by using standard solutions in conjunction with IT for data capture and reuse, allowing resources to be focussed on the more innovative and complex areas of design.

There is also scope for designers to provide additional or enhanced information to other parts of the supply chain. An example of this is providing a 3D visualisation of the solution, for use by contractors to identify potential construction problems.

To aid construction, rules that improve buildability can be incorporated into solutions, as can those to suit prefabrication or pre-assembly. Using standard components can mean lower costs and easier procurement. Proven standard solutions could reduce defects, improve certainty of delivery, reduce maintenance costs and simplify operation.

The DETR/EPSRC-funded LINK MCNS project "Building services standard solutions implemented in cad", has been set up to research the potential of standard solutions for building services. The project has a particular emphasis on applying standard solutions in conjunction with information technology.

There are many possible interpretations of what constitutes a "standard" solution. For the purposes of the LINK project, a standard solution is regarded as a solution generated by a set of prescribed rules to meet a functional requirement and application constraints.

Solutions are being developed for three areas: plantrooms, ceiling voids and risers. The rules have been split into the three generic areas of standardisation: location, sizing and selection.

To date, rule sets have been collated by the project participants to define the standard solutions and prototype software. The prototypes have user-interfaces for inputting requirements and constraints, and will output the solutions generated in conventional formats, including drawings and specifications.

For example, with the standard solution being developed for boiler rooms, the design requirements include heating output and the number and type of heating circuits (constant and variable temperature) to be served. The constraints are primarily spatial, including the physical space, connection locations and internal obstructions, such as columns and beams.

Equipment selection rules for boiler rooms are documented in terms of systems schematics. Four different standardised heating system options have been defined, with selection based on the heating output required and the number/type of loads to be served. These define the number of plant items and their configuration.

Having selected plant items, they must be sized. In some cases this will be on the basis of input data. For others, rules of thumb have been defined for use, particularly during early design. For the electrical panel board, the load requirements are taken directly from the selected mechanical plant.

The location of equipment can be approached from two angles. One is to devise a solution where the general arrangement of the main equipment is predetermined on the basis of a fairly rigid rule-set. Preferred layouts have been defined on the basis of plant either side of a shared access and maintenance route, with services above the route.

The second approach is to allow random placing of plant within the space available. This allows it to fit into different shape plantrooms. A number of possible configurations may be produced and the best selected by using a number of judgment criteria, eg spatial requirement and cost. Both approaches are currently being considered and the best method is likely to be a combination of the two.

IT implementation

The prototype software implementations of the standard solutions are made up of three distinct parts: input data, the database and the processing. The input data defines the requirements in terms of function (eg heating, cooling), capacity and constraints.

The database holds all plant objects and the attributes available for selection and incorporation into the standard solution. This data underpins the solutions and is being provided to the project by participating manufacturers in a suitable electronic format. The processing uses defined rule-sets to produce the solutions, based on the inputs and incorporating plant objects selected from the database.

The solution produced within the software environment is in essence a collection of sized objects with defined locations. This can be automatically output in a number of forms as appropriate for different parts of the design, construction and operating process. For example, space allowance, 2D, 3D layouts, or schematics, specifications and quantities.

Different levels of output will be appropriate for different stages in the design process. For example, a simple block diagram of major plant items with maintenance requirements may be appropriate for early design, whereas more detailed coordinated drawings would be needed for tender and construction purposes. Solutions have now been implemented for each service area (plantrooms, risers and ceiling voids) and are currently being checked. An important feature of the implementation is the ability to edit solutions. Standard solutions will rarely be 100% correct, therefore they should act more as templates that are, say, 80-90% correct, with the remainder edited to suit the particular application.

Barriers to standard solutions

The standard solutions that have been implemented so far are based on rule-sets developed by the project partners. It is expected that, although there may be much in common, solutions developed by others will differ according to individual company preferences.

These preferences will make establishing industry standard solutions difficult to achieve – if indeed such a standard is desirable. Variations between companies will help to maintain an element of competition and provide a driver for improving and updating solutions.

There are many real and perceived barriers to the widespread use of standard solutions, including:

 the effort required to develop and implement standard solutions

 a perception that design integrity will be compromised

 desire to put own personal stamp on project

 fear of blind use without thinking

 fear of innovation, and

 the lack of an equipment database to underpin rules

The LINK project found that significant effort was required to develop worthwhile standard solutions. However, with continuing improvements, IT capabilities and awareness, the effort required to develop and implement standard solutions should reduce in relation to the benefits.

Whether or not standard solutions will compromise design integrity will depend on how the solutions are used. The implementations developed under the project are aimed primarily at removing the burden of carrying out simple repetitive tasks from the designer. This should free up more time for innovation in appropriate areas of design.

Work is ongoing in terms of developing equipment databases suitable for this sort of application. This data could ultimately be provided by an electronic product "warehouse" with definitions following a standard format. The definitions denoting attributes including physical dimensions, maintenance requirements and performance data. In this regard there is currently considerable activity in developing object classes (for example the IAI Industry Foundation Classes) and defining the attributes and relationships of classes.

Developing good solutions to maximise benefit requires dialog throughout the supply chain and across professions. Consultation is required with contractors on buildability and construction issues, with manufacturers on equipment and products, and with architects and structural engineers to ensure integration with other building elements. There are also opportunities for electronic design software vendors on the implementation side: to add value to their products.

In theory the benefits repay the effort of developing standard solutions. However, there is not enough evidence to convince people that these approaches will work in practice and yield concrete benefits. To this end, the LINK project is now moving into the second stage: benchmarking.