Working Drawings Handbook
positioning of a given element is critical however (where,
for example, it must be a precise distance from a certain
wall face), it will be dimensioned from that face alone, to
ensure that the setter-out works in a similar fashion.
When it is critical that a feature be in the centre of a wall
face an ‘equal/equal’ indication should be given from its
centre line.
Figures 4.16and 4.17show the role of the controlling
dimension in vertical setting out. The salient levels
dimensioned from the relevant datum (in this case the
finished floor level) in the assembly section appear
again as reference planes in the larger scale detail.
The only comment that needs to be made about
components and sub-components is the general one,
that they should be dimensioned to their finished sizes.This is particularly relevant when the material involved is
timber. A note to the effect that the finished section is to
be ‘ex 150 150’ is too imprecise for a constructional
world of off-site fabrication. Economy requires that the
finished section should realistically be obtainable from
one of the standard sawn sections. To give a finished
size of 150 150, for example, would result in the client
paying for a large quantity of wood-shavings and
sawdust.4.15 Typical dimensioning of general arrangement primary elements plan. (The other general arrangement plans in
the set will not need to record these dimensions)