Civil Engineering Project Management (4th Edition)

182 Civil Engineering Project Management
For UK jobs the standard method of classification is normally used because
there are computer programs available to aid billing which are based on the
A–Z classification. For overseas work a non-CESMM method of billing is used,
which allows the classes of work adopted to follow the logical building order.
Number of items. Some civil engineering bills of quantities contain upwards
of a thousand items because many different types of operations over many
different structures are involved. Where possible, an effort should be made to
keep the number of items to no more than they need be. This helps to reduce
the work involved in measurement throughout the contract; but departures
from the standard method may make the estimator’s task more difficult and
so should be kept to the minimum necessary.
The question of how detailed the billing should be depends on the nature
and size of the works. What is to be measured for payment can vary widely.
For instance, in a contract for the construction of a dam, some minor gauge
house might be billed as a single lump sum item; the drawings and specification
providing all details of what is required. Often where there are repetitive
structures, such as access chambers to valves on a pipeline, these too can be
billed complete by number.
In civil engineering it is quite common to bill items, such as standard doors
simply by number, the specification describing what is required including
the frame, priming and painting, and the type of door furniture required. If a
special door is required, such as for the front entrance, again this is shown on
the drawings and specified in detail; so the item in the bill appears as ‘Front
entrance door … 1 No. … ’.
Where methods of measurement depart from the ICE standard method, this
must be made clear in the bill. Although the standard method permits the
description of an individual item to make clear it is not measured according to
the standard method, it is better to group such items together. Either they can be
grouped under some appropriate sub-heading, or it may be decided that certain
types of work throughout the bills are not to be measured according to the standard
method. When this policy is adopted, a statement must appear in the preamble
to the bills of quantities (see below) saying such as ‘Painting of metalwork
is not measured separately and is to be included in the rate for supply and fixing
of metalwork’. To prevent errors, a sub-heading before metalwork items should
repeat this briefly, for example, ‘Following items including painting’.
15.5 Accuracy of quantities: provisional quantities
In preparing the bills, the quantities should be accurately taken off drawings
in accordance with the method of measurement. The quantities billed should
not contain hidden reserves by ‘over-measuring’ them when preparing a bill.
There may be a temptation to do this when, for instance, billing the trench
excavation for a pipeline. But if the engineer increases the length at greater
depth and decreases that at shallow depth to compensate, he may give the