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The ‘biscuit tin’ floor box with its piano‐hinged lid has become the standard vehicle for connecting the cable which is fed below the raised floor to the desk equipment. Sometimes the unit has been specially developed — at what one can only presume to be considerable cost in the case of prestigious buildings like the Norman Foster Hong Kong & Shanghai Bank headquarters. In most installations, they are more mundane derivatives of the floor box which was housed in the floor screed and provided on a design module of something between 1.5 and 2m. Despite the greater flexibility supposedly inherent in a raised floor solution, the reality is that the floor box in the raised floor copes no better with the transition between the ‘secondary’ and the ‘tertiary’ wiring than it did in the screeded floor.

This pair of articles will examine the decision making process in establishing the brief for the electrical installation for an electronic office. In my own working lifetime the office electrical installation has changed from a tungsten lamp in an opal glass bowl in the centre of the room and a two or five or occasionally 15 amp power point, to the single most expensive item in equipping an office building intelligently.

Table 1 represents a preliminary summary of the installed electrical load for a building. Such figures could well be found in a building with a reasonably high technology usage and a size of about 100 000 sq ft net usable space. It has been assumed that the occupancy rate would be 1:120 sq ft but the design could be in accordance with such other formulae that the brief indicated. Other loads would have been obtained by discussion with the important players such as the dataprocessing (DP) manager or director of technology. The loads would have been projected over the time‐scale that was the basis of the company's current planning programme.

There can scarcely be a facilities manager who is not beset by cabling problems or familiar with horror stories of bad cabling. Several eminent reports have highlighted the problem of shoehorning cables into buildings which have not been designed with their provision in mind. The majority have been installed in an ad hoc fashion without any understanding of what the overall requirement was or will be. Even where facilities such as false floors existed, freedom led to anarchy. As a result, some of these privileged users have been forced to relocate if they wanted to change their cabling system.

Structured cabling systems remain a fast growing market and are likely to become even more frequently installed as the recession recedes. The historical derivation and structure of these systems is described and the key strategical issues which will need examining when selecting a system are highlighted.

Last month we discussed methods of establishing the total quantum of an electrical supply. Three strategic issues were also introduced — the need to provide for growth, flexibility in operation and a continuous and stable operation. This last point will be the focus of this month's article.

Deals with the Electricity at Work Regulations, which have been in force since April 1990. Their introduction was necessitated by, inter alia, the unscrupulousness and incompetence prevalent amongst suppliers and installers of electrical appliances. Seeks to clarify some of the issues and enable facilities managers to build a framework in which they can operate and ensure compliance with the regulations.

Outlines the possible advantages and disadvantages of flat cabling as a means of information and power distribution. Considers methods of installation, the power cables, circuit protection, data and telephone cables, and the speed of installation. Examines problems that arise in practice. Concludes that the original cabling design is critical.

Last month's survey of the types of cableway system available made mention of British Telecom's interest in the matter. Only time will reveal any changes which privatisation will make, but clearly BT will remain effectively a monopoly: a consideration of its existing attitudes is, therefore, relevant to your plans for any new installation.

Lighting information covers a wide spectrum, from the highly technical to the highly subjective. To narrow the focus for the facilities manager we brought together a panel of people with a wide range of experience of lighting problems and asked them — a building services manager, electrical contractor, lighting supplier, architect, human factors researcher and consulting engineer — What does an office lighting user need to know?