WORKING DRAWINGS HANDBOOK, Fourth Edition

Working Drawings Handbook

2 When we talk of elementalising the drawings we are
in effect talking almost exclusively of the general
arrangement drawings. These are the only drawings
which will be drawn elementally in the sense that the
same floor plan, for example, may be shown several
times—either by CAD or manually—to illustrate the
various elements contained within it. All other
categories of drawing—assembly, component,
sub-component, schedule—may well fall within one
or other of the elemental sub-divisions; but they will
be drawn uniquely and will appear only once in the
drawing set.
3 Although all the facets of Uniclass Table G are
available, like so many pigeon-holes, to receive the
various drawings prepared, there is no particular
virtue in trying to use them all. In practice a very few
will suffice, even for the larger projects. Never forget
the two-fold objective of this secondary structuring,
which is to provide both a disciplined framework for
the draughtsman and a simple retrieval method for
the seeker after information. A drawing set containing
a couple of drawings in each of some thirty elemental
sub-divisions assists the achievement of neither.
4 Given a true understanding of the objectives
common sense is the paramount consideration.

With this in mind Table G might well be simplified into:

Such a division will probably be adequate for coding all

but the very largest and most complicated projects. If it

should be found desirable however to deal separately

with, for example, doors and windows, the further sub-

divisions G321 and G322 are available.

CI/SfB

An alternative method is in existence which fulfils most of

the requirements of an elemental structuring system and

which has the advantage of being already well established

within both the profession and the industry. This is the

CI/SfB method of classification, and while it has its

detractors, who legitimately point to certain weaknesses in

detail, it has so many advantages in logic and flexibility

that on balance it must be recommended. The CPI

documents accept it as a viable alternative to Uniclass

Table G, and consequently it will form the basis of most of

the drawings illustrated in subsequent chapters.

Its virtues are:

 It is currently the most widely known and used of

available classification methods.

 It is comprehensive in its scope, offering

opportunities for uniting the output of different

disciplines into a common package.

 It is capable of operation at various levels of

sophistication, making it suitable for both large and

small projects.

 It is fully compatible with the Co-ordinated Project

Information elementalised concept.

 It is compatible with the use of computer-aided

draughting.

The complete CI/SfB system is undoubtedly complex

(though considerably less so than Uniclass Table G),

and some tend to shy away from it, frightened at the

prospect of having such a sophisticated sledge-hammer

to crack such small nuts as are the mainstay of the

average practice. This is a pity, for that aspect of CI/SfB

which is of greatest relevance to the drawing office is in

fact of a disarming simplicity. (It is certainly less

G1 Site preparation

G21 Foundations

G22 Floors

G24 Roofs

G25 Walls

G26 Frame

G32 Openings

G33 Internal finishes

G4 Fittings/furniture/equipment

G5 Services

G52 Heating/ventilation/air conditioning

G54 Lighting

G7 External works.