Working Drawings Handbook
Planning the set
The structure of the final production set of drawings is
central to both the smooth running of the project on site
and the economics of the office producing it. It must
therefore be considered in some detail.
General arrangement plans
Given that the set is to be structured in the manner
recommended in the earlier chapters the first decision to
be made (and as noted earlier it will have been sensible
to make it before preparation of the final design
drawings) relates to sheet size and scale of the general
arrangement plans. Basically the choice lies between a
scale of 1:50, permitting a relatively large amount of
information to be conveyed on a single sheet, or 1:100
where a greater degree of elementalisation will be
required if the sheet is to remain uncluttered and legible,
and where its main purpose is to provide a ready
indication of where other and more detailed information
is to be found.
A number of considerations will determine this decision,
but they will centre around the size and complexity of
the project. Housing and conversions are normally best
carried out at the larger scale. Larger projects are often
better suited to an elementalised set of general
arrangement plans.
Most CAD programmes work at 1:1. This means that the
CAD ‘model’ is created full size, and that only later will
views of this ‘model’ be created, and only then that the
drawings will be assigned their plotted scale. It is
obviously important that every drawing be presented at a
recognisable scale in general use in the building industry.
In the discussion that follows it will be assumed that a
single multi-storeyed building of some £2 000 000 contract
value is being dealt with (the building, in fact, parts of
which have been used previously in Chapters 1 and 2),
that a drawing team of three or four people will be
involved, and that the decision has been made to produce
1:100 general arrangement plans, elementalised for clarity.Assuming that the set is to be produced by CAD, the
first allocation of files will be to general arrangement
plans, one for each plan level. They will be coded G(— —)
i.e. ‘The project in general’, because they are the basis
from which the subsequent elementalised layers will be
produced. (As has been noted in Chapter 4, numbering
of the plans by floor levels is a refinement which, apart
from possessing a certain elegance for the system-
minded, offers eventual benefits to the site staff).The basic plans having been established it is necessary
to consider what elemental plans should spring from
them. The CI/SfB project manual offers a sensible
method for identifying these. The complete range of
elements in CI/SfB Table 1 is available and offers a
useful check list (see Chapter 1).Generally speaking, however, few projects—and then
only those containing problems of a specialised
nature—will need to go beyond the much more limited
range shown in Table IV.Other general arrangement drawings
Site plan, elevations and basic sections complete the
general arrangement set. The complexity of the external
works will influence the decision on whether or not to put
all general arrangement information on a single drawing.
This is an area where coordination of information is of
paramount importance and this may outweigh the other
advantages inherent in the elemental approach.General arrangement sections
These are best identified from the final design drawings.
The external envelope of the building will generate the
majority and the most important of these, so the
approach illustrated in 5.7is useful. Bearing in mind
that the approach initially is in terms of strictly limited