Common Arrangement of Work Sections
It was developed as a result of research demonstrating that the quality of construction information was a very significant determinant of the quality of construction. It was recognised that standardisation of the way production information was created and classified could help improve quality, and that the commonly used CISfb classification was not sufficiently comprehensive to achieve this.
CAWS established a consistent arrangement for specifications and bills of quantities. It was first published in 1987 and was updated by CPIC in 1998 to align it with the Unified Classification for the Construction Industry (Uniclass). In 2005 nbs submitted to CPIC, modifications to the services sections of CAWS for consideration and following 5 years of consultation these changes were accepted.
CAWS is the categorisation of work that is used for the National Building Specification (nbs – which before 1987 followed the CISfB structure), National Engineering Specification (NES), the Standard Method of Measurement, currently in its 7th Edition (SMM7) and a number of industry pricing books such as Spons, Laxtons and Wessex.
CAWS has since been incorporated into Table J of Uniclass, which was also developed by CPIC. Uniclass is a classification system for organising library materials, product literature and project information.
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.
The main categories are:
- A - Preliminaries
- B - Complete buildings / structures / units
- C - Demolition / Alteration /Renovation
- D - Groundwork
- E - In situ concrete / Large precast concrete
- F – Masonry
- G – Structural / Carcassing metal / timber
- H - Cladding / Covering
- J - Waterproofing
- K - Linings / Sheathing / Dry partitioning
- L - Windows / Doors / Stairs
- M - Surface finishes
- 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
- Z - Building fabric reference specification
Each section includes further sub-classification and offers detailed information and supplementary rules. For more information see: Common arrangement of work sections classification.
 Related articles on Designing Buildings Wiki
- Bills of quantities.
- BIM classification.
- Classification, an introduction.
- Common arrangement of work sections classification.
- Comparison of SMM7 with NRM2.
- Construction Project Information Committee.
- Elemental cost plan.
- How to take off construction works.
- New Rules of Measurement.
- Production information.
- Standard Method of Measurement (SMM7).
 External references
Featured articles and news
CEOs and high-level executives explain who they expect to be the most successful players in the future of construction.
What are package contracts and how are they broken down? Find out in our introductory article.
Identifying sustainable shoreline protection solutions in the face of rising sea levels and storms in the US.
Budget documents state modern methods of construction will be favoured for public infrastructure schemes from 2019.
A walk-through exhibition of an emergency humanitarian shelter is officially opened at BRE's Innovation Park.
How to work safely on a construction site during winter.
Housing is the big winner in Chancellor Philip Hammond's Autumn Budget.
The winner of our BSRIA competition, Tomorrow's challenges in today's buildings, is.... Bob Hendrikx. A big thank you to everyone that took part.
Committee of MPs accuses government of dealing billpayers a 'bad hand' over the guaranteed power price.
In 1992, the Joint Fire Code was first published. What influence does it still have on construction sites today?
"Companies will have to adapt or go out of business" - how are virtual reality and big data disrupting digital construction?
International Well Building Institute and BRE collaborate on multiple levels to advance human health through better buildings.
"The industry has tried moving away from prescriptivism to focus on performance, but maybe that’s no longer working".