Promoting collaborative working within the construction industry
Section 3.3.2 recommends that on larger projects drawings and bills of quantities (if used) identify and cross-refer to the different kinds of work but do not specify them. It follows that an overriding consideration is the need for the specification to be referred to easily, and for the contents to be co-related speedily and certainly with the drawings and any quantities.
On larger projects the specification is used by a wide variety of people and organisations. Whilst some (e.g. main contractor, management contractor, project manager, architect, clerk of works) will need to have easy reference to the complete specification, the many specialists, subcontractors and suppliers will be concerned only with the information relevant to them. The specification should therefore be arranged in sections that relate closely to the pattern of subcontracting, making it easier to divide up and distribute to obtain estimates and arrange for construction of the various types of work.
The Common Arrangement of Work Sections (CAWS) was devised with this in mind, and should be followed closely. CAWS forms Table J of Uniclass (RIBA Publications 1997), and is published with section definitions as a separate document (CPIC, Second edition 1998).
The classification is set out in three levels as follows:
CAWS includes about 300 work sections, reflecting the large range of specialists and subcontractors that now exist. Each work section has a detailed definition in order that project documents can be consistent in their arrangement and to help ensure that gaps and overlaps between sections do not occur (an example definition is given in Figure 4.1). The work sections are smaller and more specific than the traditional 'trades', so only 20% to 30% of the 300 sections will apply to a typical project.
It is intended that project specifications and bills of quantities use level 1 and level 3 headings and codes, but not level 2. The simple alphanumeric coding of CAWS facilitates looking up of specification cross-references given on the drawings, in bills of quantities, instructions, correspondence, telephone calls, etc (see Section 4.1.5).
K40 Demountable suspended ceilings
False ceilings of dry construction comprising a membrane of tiles, panels, trays, etc., supported by exposed or concealed suspended metal grids. The membrane is normally demountable, in part or in whole, to give access to the ceiling space. Lighting, ventilation, fire prevention and other services may be integrated with the suspended ceilings.
Suspension and framing members
Self finished tiles, boards, panels or strips
Integral heating, ventilating, lighting or fire prevention fittings and outlets
Perimeter trim (where to be provided by suspended ceiling specialist)
Cavity fire barriers
Sound barriers (coinciding with partitions)
Air plenum barriers
Reveals to rooflight openings, changes of level
Stretched plastics membrane ceilings
Soffit linings on battens, etc. fixed direct to underside of slab
Dry lined plasterboard ceilings
Wet plaster ceiling membranes including plasterboard backings
Sprayed mineral fibre coatings, M22
Metal lathing for plastered and sprayed mineral fibre ceiling membranes
Perimeter trim, where not provided by specialist
Holes/Chases/Covers/Supports for services, P31
Connections to services installations
Second edition changes
Title amended. Plasterboard dry lined ceilings now included in section K10
Figure 4.1 Example definition of a CAWS work section
CAWS groups Y and Z provide 'reference specification sections'. The purpose of these is to reduce repetition by giving specification that is bulky and common to several 'work' sections, e.g. Y20 Pumps and Z21 Mortars. The reference specification section can then be invoked by reference in the relevant work sections. Variable specification, e.g. pump ratings, mortar mixes, should be given in the work sections rather than the reference specification sections.
Within each work section the information should be coherent and in a rational sequence. Clauses should be of the following types:
For some purposes sections will be read from beginning to end, but for much of the time specifications are used in the manner of an encyclopaedia to check on particular products or other requirements. Helpful headings and keywords are therefore essential.
The main principles of clause structuring are:
LENGTH OF CLAUSES: Strike a balance between too short (staccato) and too long (rambling). Two to six lines is about right, but can be more if sub-itemised.
SUB-ITEMISATION can be used to:
CROSS-REFERENCING: Where there is a need to cross-refer to the specification for information on a particular item of construction, a single clause that deals with every specification variant of that item should be provided, so that the reference can be simple (see above - work type, equipment and accessories clauses).
KEYWORDS: To assist scanning pages by eye to find particular items of information, each clause should be devoted to a single subject, with one or more words in upper case at the beginning, chosen to reflect the subject. Keywords will usually be the generic name of the product, the feature or part of the work being constructed, or the name of the operation. It is usually unhelpful to choose a verb, e.g. 'STAIR NOSINGS: fix with _ _ _ _' rather than 'FIX stair nosings with _ _ _ _'.
SEQUENCE of clauses should be clear and rational in the context of the headings. This should show through in the keywords.
TERMINOLOGY: Where appropriate use terms defined in BS 6100 'Glossary of building and civil engineering terms'. Terms and acronyms defined in preliminaries (e.g. 'SO', 'equivalent approved') should be used consistently.
ADDRESS THE CONSTRUCTOR DIRECTLY: 'The contractor shall' and similar phrases are not necessary.
QUALITY OF WRITING: Write directly, simply and clearly. This can be difficult to achieve, and use of well written, carefully considered standard clauses usually offers significant advantage over writing from scratch.
The specification will define the various kinds and qualities of work, and can also give information on where they occur to facilitate correlation with the drawings. Work type clauses in particular (see Section 4.1.3 above) can include location information, e.g.:
Section 3.1.2 discussed location information schedules, traditionally regarded as drawings, and proposed that they usually can and should now be regarded as part of the specification. On a large project there can be many such schedules, most of which give significant specification information (rather than just references to the specification), and are confined to one CAWS section. Such specification information can be conveniently included as work type clauses in the relevant specification section, e.g. Doors (L20), Windows (L10), Ironmongery (P21), Sanitary fittings (N13), Light fittings (V21), Radiators (T30), Manholes (R12), Piles (D30), Exterior planting (Q31).
To be included in the specification, the information needs to be formatted to go onto A4 paper, or a larger size reduced to A4. The 'matrix' format traditionally used on drawn location schedules can, if desired, be used, but the number of columns will be strictly limited. An 'itemised' format is usually more suitable, and is consistent with the presentation of work type clauses elsewhere in the specification - see Figure 4.2.
Figure 4.2 Itemised format work type clauses
On most larger projects there are three cases where the location information usually relates to several CAWS sections, and can be sufficiently large to merit special treatment: doors, internal finishes, and fittings and fixtures. In these cases the information can be presented more concisely and used more easily if it is broken down into two levels:
Figure 4.3 Location schedules included in the specification
Bending schedules for concrete reinforcement are another special case. They contain graphic diagrams, and give shape and size rather than specification quality. They may be regarded as part of the concrete reinforcement drawings, but if preferred they can be produced on A4 paper and appended to section E30 of the specification.
Drawings should be annotated with precise and succinct 'identification' cross-references, e.g. 'Facing blockwork F10/110' (see Section 3.3.2), but not indiscriminately. Each reference should be for a good reason. References should, in the main, be on assembly drawings.
The example in Figure 4.4 has been produced specifically to illustrate specification referencing of drawings; it does not purport to be complete. The highlighted references, e.g. R12/121 are to the selected specification clauses given in Figure 4.5.
Figure 4.4 Annotation of drawings with specification references
Figure 4.5 Clauses from Section R12, referred to in Figures 4.4 and 4.7
To ensure consistency in the drawings for a project, the cross-references that will be needed can be predetermined, included in a list, and copied onto the drawings as required. The list can also be used to ensure that the item descriptions in bills of quantities tally with the drawings annotations, to prevent cost significant discrepancies and divergences. Figure 4.6 shows part of such a list.
Highdown Centre: specification reference list
Repair and repoint boundary wall C41
(List incomplete – remainder not given for sake of brevity)
Figure 4.6 Example specification reference list
Where bills of quantities are provided, the SMM7 General Rules specifically permit cross-reference to drawings and specification in lieu of full description. Figure 4.7 gives an example.
Figure 4.7 Bill of quantities with specification references
Arranging the bill of quantities by CAWS will: