Andrew Wilson, NBS Scheduler coordinator, clears up our thinking on how schedules of work work. This article is paired by another, 'The structure of a schedule of work.
There is considerable scope for confusion in discussing schedules of work – usually arising from the lack of a generally accepted definition of structure and content, but also from disagreements over terminology, and whether inclusion of quantities within a schedule of work is valid.
One aspect of the schedule of work that should not be in dispute is its general form and purpose, and for this article the essence of a schedule of work could hardly be simpler. It is a list – in this case a list, either in outline or detail, of building work. In common with any list it may be used for different purposes, by different people at different times. It may be accompanied by, or bound in with, other documents.
Even simple building work can require a lot of description and the schedule of work is usually accompanied by other documents providing information supplementing the listed items, including:
- drawings – to illustrate extent of the work;
- schedules – itemized lists of particular product types, commonly doors, windows, ironmongery, finishes and decorations;
- some form of specification – to describe the standards to which each category of work is to be carried out; and
- preliminaries – to determine general requirements for the project as a whole,usually with reference to a particular standard form of building contract.
Differing uses throughout project
A simple list can serve a number of uses, and the schedule of work is no different. Together with the supporting documents, it may be used in the following ways:
- Tender document.
- Contract document.
- Task list for work on site.
- Check list for administration.
- Record document.
The purpose of the schedule of work at tendering stage is to provide sufficient description of the proposals to allow a number of independent building contractors (usually a minimum of three) to calculate fair and, hopefully, competitive prices for the work. In general this task will be undertaken by quantity surveyors (who may be employed directly by the contractor, and are then generally referred to as 'estimators'). They will price listed items to determine an overall cost.
The descriptions in the schedule of work must be unambiguous. They need not be complete in themselves, but may cross refer to the accompanying documents – particularly to the drawings. However, they must cover, at least in outline, all aspects of the work for which prices are required. Taken together the information provided must allow the contractor to identify all the materials needed and to calculate the quantities that will be required.
Once a price has been agreed the schedule of work will form part of the legally binding 'contract documents' between employer (the building owner) and contractor.
The schedule of work, exactly as issued for tendering purposes, is also used on site by the contractor's workforce on a day to day basis to determine work required during construction. For use on site, the schedule of work and accompanying documents must not only identify the materials and allow calculation of quantities involved, but also give precise instructions on where all the materials are to be used and how they are to be fixed together. It should also set out an ordered arrangement of tasks to be carried out, in the correct sequence to achieve the desired end result.
The contract administrator (CA – who may be an architect, an architectural technologist, a building surveyor or other construction professional) is not necessarily the individual who wrote the schedule of work or produced the drawings. The CA will use the schedule of work to check that each of the listed items is being – or has been – carried out. The CA may also use the prices against checked items in the schedule of work to periodically calculate the value of the completed work.
The original schedule of work and supporting documents, together with descriptions of variations from the work originally intended, may be archived as an 'as built' document set for record purposes. In certain instances, if serious faults are later found, the schedule of work, as part of this document set, will again be studied in detail.
In general it is likely that the schedule of work must be read, and understood, by perhaps four or more sets of people who must each be able to use the document (and its supporting documents) to gain a particular understanding of the building. The extent to which these aims may be met depends largely on the structure of the schedule of work itself. There must be a methodology behind the description that relates closely to the type and extent of the work being carried out.