The schedule of work is rarely, if ever, used in isolation. It is commonly bound together with contract preliminaries (describing general project requirements and contract terms) and with a specification document describing minimum acceptable product and workmanship standards. This group of documents may then be supported by drawings and itemized lists (also, confusingly, known as schedules), bundled separately or bound in as appendices.

The schedule of work is the core of this document set and, particularly where its descriptions are in outline, it must cross refer to the supporting documents. Inevitably it may become relatively complex. This complexity must be controlled, and this can best be done by careful selection of an appropriate structure for the schedule of work.

The types of building work for which schedules of work are used vary widely but there are, typically, two extremes – new work and maintenance/ refurbishment work – which are best met by wholly different formats of description.

In all cases the schedule of work need not be fully descriptive if work is covered in detail on drawings etc. The only essential is that the schedule of work provides a pricing point for all work – the complete description may lie elsewhere.

New work

Imagine a very simple new brick walled two storey house with a tiled pitched roof. There is really only one way in which this can be built – from the bottom up. First, existing buildings or vegetation on the site must be cleared to allow work to take place at all. Then foundation trenches must be dug and foundations laid, followed by the lowest course of the walls and then the ground floor slabs. Walls are then built up to support upper floors and roofs. Services are installed and the whole building plastered out and decorated. Finally the site is tidied up, fences and garden walls constructed and planting carried out.

A logical format for the schedule of (new) work is to mirror this activity, so the schedule of work will be arranged under 'elemental' headings such as 'site clearance', then 'foundations', 'walls below damp proof course', 'ground floor slabs' continuing through to 'upper floor structure', 'roof structure', 'roof covering' and completed by 'plumbing', 'electrical work', 'decorations' and, finally, by 'external works', all laid out in construction sequence.

Such a format is a helpful progression not only for the specifier trying to ensure that everything is covered, but also for the tenderer putting costs to the work and for the operatives on site putting the building together. For a very small building there may be little need to divide each element into smaller parts. For a larger building the main headings would be much the same, but each might then be subdivided. Rather than 'roof covering' there might be separate headings or descriptions for 'porch roof covering', 'main roof covering' and 'dormer roof covering' – each to be priced (and, obviously, constructed) separately.

The extent of this division should also take account of any need for valuing the work during construction. It is the expectation of most forms of contract for small works that valuations will be carried out (and payments made to the contractor) on a monthly basis. In general the method of valuation by the contract administrator will be to determine, as closely as reasonably possible, the percentage complete of each piece of work priced in the tender – so a tiled roof on which 50% of the tiling has been completed will be valued to give a maximum of half the contractor's tender price for the roof tiling. This task will be made much simpler and more transparent if each priceable item is relatively simple – this may require separate priceable items for, e.g. 'purlins', 'rafters', 'insulation between rafters', 'roof underlay and counterbattens', and 'tiling battens and roof tiling'.

Refurbishment work

Refurbishment/ maintenance work is very different in that all parts of the building already exist and there may be no compelling reason, as far as the specifier is concerned, to describe one particular type of work before another.

Maintenance work commonly involves repair or replacement of doors, windows, fences, rainwater goods etc. Given that contractors pricing the work and operatives carrying it out will tend to deal with all items in a particular location before moving on to the next, this is also the pattern commonly used for a 'locational' structure to a schedule of (refurbishment/ maintenance) work.

Actual headings will depend on how well defined is the use for each area of the building. A house or apartment refurbishment is likely to use headings such as 'porch', 'hall', 'lounge' and 'kitchen', whilst an office building might be better served simply by 'room 1', 'room 2' etc. In general each element within each room will be described and priced separately, making valuation by the contract administrator during the course of the work relatively straightforward.

Other structures

There are, of course, many possible variations within these extremes. Alteration work commonly involves refurbishment/ maintenance together with elements of new work, e.g. new partitions, that may not best be described as belonging to a particular room. In such a case the structure for the schedule of work may require to be split to identify new work separately from refurbishment/ maintenance.

The key always is to identify and outline the most appropriate structure for a schedule of work before starting the description of the work itself.