This article is all about the Common Arrangement of work sections for building works.
What's in this Article ?Toggle
The Common Arrangement of Work Sections (CAWS) is a recognised arrangement for specifications and bills of quantities in the construction industry.
First published in 1987, it was created by the Construction Project Information Committee (CPIC) with representatives from key stakeholders across the construction industry.
There are dozens of work sections broken down into groups and sub-groups including:
Reference- Work section
A – Preliminaries/General conditions
B – Complete buildings / structures / units
C – Demolition / Alteration /Renovation
D – Groundwork
E – In situ concrete / Large precast concrete
F – Masonry (brickwork/blockwork/stonework)
G – Structural / Carcassing metal / timber
H – Cladding / Covering
J – Waterproofing
K – Linings / Sheathing / Dry partitioning
L – Windows / Doors / Stairs
M – Surface finishes (plastering/tiling, painting etc.)
N – Furniture / Equipment
P – Building fabric sundries
Q – Paving / Planting / Fencing / Site furniture
R – Disposal Systems
S – Piped supply systems
T – Mechanical heating / Cooling / Refrigeration systems
U – Ventilation / Air conditioning systems
V – Electrical supply / power / lighting systems
W – Communications / Security / Control systems
X – Transport systems (lifts, escalators etc)
Y – General Engineering Services
Z – Building fabric reference specification
CAWS are produced by the CPIC as well as the Uniclass system of work sections. The CPIC also produces the Construction Project Information Code which provides best practice advice on how to produce drawings, specifications and bills of quantities.
CAWS is simply a method of classifying huge amounts of information that inevitably exists in the construction industry.
In 1987, it replaced the old CISfB Indexing system which was used by the National Building Specification, National Engineering Specification (NES), the Standard Method of Measurement (SMM7) and a number of industry pricing books such as Spons, Laxtons and Wessex.
In every construction project, the head Client needs to assert exactly what they want their finished product (the building) to look like and what products and materials are to be used.
To this end the Architect creates a specification which is simply a long list of the details all the materials and products to be used. This list could easily run to 500+ pages so there needs to be a way of making the list accessible to anyone who needs that information e.g. the builder and their sub-contractors and suppliers.
Its like going into a library and being able to find one book out of all the thousands. A flooring contractor needs to find his relevant section in the specification document that could be hundreds of pages long.
So, to that end the specification is divided up into natural common groups and sub-groups which each group getting a single letter of the alphabet and sub-groups getting a number. e.g. T10 is a group all about Gas/oil fired boilers.
CAWS created a consistent arrangement for specifications and bills of quantities.
Uniclass is a classification or indexing system that can be used to index library books, product literature, project information and so on.
The Uniclass system was developed by the NBS from the CAWS system which concentrates on classifying things in a different way.
CAWS has since been incorporated into Table EF of Uniclass (it was previously table J), which was also developed by CPIC.
Table EF includes:
EF_15 Earthworks and remediation
EF_20 Structural elements
EF_25 Wall and barrier elements
EF_30 Roofs, floor and paving elements
EF_35 Stairs and ramps
EF_37 Tunnel, vessel and tower elements
EF_40 Signage, fittings, furnishings and equipment
EF_45 Flora and fauna elements
EF_50 Waste disposal functions
EF_55 Piped supply functions
EF_60 Heating, cooling and refrigeration functions
EF_65 Ventilation and air conditioning functions
EF_70 Electrical power and lighting functions
EF_75 Communications, security, safety and protection functions
EF_80 Transport functions
In 2005 the NBS submitted to CPIC, modifications to the services sections of CAWS for consideration and following 5 years of consultation these changes were accepted.
In 2011, the CPIC used the NBS proposals for re-classification of the work sections in CAWS and Uniclass Table J as the basis of a consultation process for revising Uniclass.
This development of Uniclass as a whole is considered to better accommodate civil engineering and process engineering alongside architecture and landscape, it also better enables the description of systems in performance terms, and is more suited to accommodating facilities management.
When in 1998 the CPIC updated CAWs to align it with the Unified Classification for the Construction Industry (Uniclass) the quantity surveying industry updated its method of measurements to distance itself from any method of classification or indexing.
Remember, Uniclass and CAWS are systems of classification, of indexing. They are incredibly useful for organising and indexing huge amounts of information such as a construction specification. The quantity surveyors standard method of measurement used to be laid out just like the CAWS system. Now this method of measurement has been replaced by National Rules of Measurement 1,2 & 3. NRM is not a system of classification and so is not in competition with Uniclass. Thats the big point to understand — NRM is all about best practice of taking off quantities from drawings whilst CAWS and Uniclass is all about organising information.
So, now the only difference to pre 2013 (the date when NRM came into effect) is that instead of the Architects specification indexing matching with the quantity surveying bill of quantities work sections they are different.
Which to be honest does not make any difference to anyone in the construction industry at all.
As long as the bill of quantities or any pricing document makes reference to the correct part of the Architects or Engineers specification then everything is fine.
The bill of quantities references do not need to match up with the specification references, they just need to be linked. For example, if a flooring contractor reads in the BOQ that he must refer to specification item xxxx he can simply just do that.
The following publications now refer to the codes in the NRM2 work sections instead of CAWS or Uniclass:
This distances the quantity surveyors measurement of costs from the indexing of construction information within the specifications and drawings.
Conclusion – the RICS has its own method of measurement. It uses these measurement rules to create cost estimates, cost plans, schedules of work and bills of quantities as well as organise their rates. They really don’t care which indexing system their pricing documents refer to. So a bill of quantities can refer to whatever format the Architect uses in their drawings and specifications.