Common arrangement of work sections classification
The Common Arrangement of Work Sections (CAWS), provides a consistent arrangement for specifications and bills of quantities. For more information see Common Arrangement of Work Sections.
The Common Arrangement of Work Sections sub-classification is listed below:
B: Complete buildings / structures / units
| B11 | Prefabricated building units |
| B12 | Conservatories |
| B13 | Modular buildings |
| B14 | Prefabricated panelled constructions |
| B15 | Prefabricated framed constructions |
| B50 | General structural requirements |
| B91 | Buildings in the landscape |
C: Demolition / alteration / renovation
| C10 | Site survey |
| C11 | Site investigation |
| C20 | Demolition |
| C30 | Shoring / facade retention |
| C40 | Cleaning masonry / cleaning concrete |
| C41 | Repairing / renovating / conserving masonry |
| C42 | Repairing / renovating / conserving concrete |
| C45 | Damp proof course renewal / insertion |
| C46 | Cavity wall tie renewal / insertion |
| C51 | Repairing / renovating / conserving timber |
| C52 | Fungus / beetle eradication |
| C90 | Alterations – spot items |
D: Groundwork
| D20 | Excavating and filling |
| D21 | Ground gas collection and venting systems |
| D30 | Piling |
| D40 | Embedded retaining walls |
| D41 | Crib walls, gabions and other gravity retaining walls |
| D45 | Soil nailing |
| D50 | Underpinning |
E: In situ concrete / large precast concrete
| E05 | In situ concrete construction generally |
| E10 | Mixing / casting / curing in situ concrete |
| E11 | Sprayed in situ concrete |
| E20 | Formwork for in situ concrete |
| E30 | Reinforcement for in situ concrete |
| E40 | Designed joints in in situ concrete |
| E41 | Worked finishes to in situ concrete |
| E42 | Accessories cast into in situ concrete |
| E60 | Precast / composite concrete floors / roof decks |
F: Masonry
| F10 | Brick / block walling |
| F11 | Glass block walling |
| F20 | Natural stone rubble walling |
| F21 | Natural stone / ashlar walling / dressings |
| F22 | Cast stone ashlar walling / dressings |
| F30 | Accessories / sundry items for brick / block / stone walling |
| F31 | Precast concrete sills / lintels / copings / features |
| F42 | Straw bale walling systems |
G: Structural / carcassing metal / timber
| G10 | Structural steel framing |
| G11 | Structural aluminium framing |
| G12 | Isolated structural metal members |
| G13 | LSF Light Steel Frame |
| G20 | Carpentry/Timber framing/First fixing |
| G21 | Load-bearing timber blockwork |
| G22 | CLTP Cross Laminated timber panel systems |
| G23 | Post and Beam frames |
| G24 | Laminated timber frames |
| G25 | LTF Light Timber Frames |
| G26 | SIPS Structural Insulated Panel Systems |
| G27 | ISPS insulated structural panel systems |
| G28 | Dowelled/Nailed stacked wood panel systems |
| G3 | Metal/ Timber decking |
| G30 | Metal profiled sheet decking |
| G31 | Prefabricated timber unit decking |
| G32 | Edge supported/Reinforced woodwool slab decking |
H: Cladding / covering
| J10 | Cementitious mortar tanking / damp proofing |
| J20 | Mastic asphalt tanking / damp proofing |
| J21 | Mastic asphalt roofing / insulation / finishes |
| J30 | Liquid applied tanking / damp proofing |
| J31 | Liquid applied waterproof roof coatings |
| J40 | Flexible sheet waterproofing / damp proofing |
| J41 | Reinforced bitumen membrane roof coverings |
| J42 | Single layer polymeric sheet roof coverings |
| J44 | Sheet linings for pools / lakes / waterways |
K: Linings / sheathing / dry partitioning
| K10 | Plasterboard dry linings / partitions / ceilings |
| K11 | Rigid sheet flooring / sheathing / decking / sarking / linings / casings |
| K12 | Under perlin / Inside rail panel linings |
| K13 | Rigid sheet fine linings and panelling |
| K20 | Timber board flooring / sarking / linings / casings |
| K21 | Wood strip /board fine flooring / linings |
| K30 | Panel partitions |
| K32 | Panel cubicles / duct and wall linings / screens |
| K40 | Demountable suspended ceilings |
| K41 | Raised access floors |
| K45 | Suspended ceiling system alterations |
| K46 | Raised floor system alterations |
| L10 | Windows / rooflights / screens / louvres |
| L20 | Doors / shutters / hatches |
| L30 | Stairs / ladders / walkways / handrails / balustrades |
| L35 | Fixed utilitarian access systems |
| L40 | General glazing |
| M10 | Cement based levelling / wearing screeds |
| M11 | Mastic asphalt flooring / floor underlays |
| M12 | Resin flooring |
| M13 | Calcium sulfate based levelling screeds |
| M20 | Plastered / rendered / roughcast coatings |
| M21 | Insulation with rendered finish |
| M22 | Sprayed monolithic coatings |
| M30 | Metal lathing / anchored mesh reinforcement for plastered / rendered coatings |
| M40 | Stone / concrete / quarry / ceramic tiling / mosaic |
| M41 | Terrazzo tiling / In situ terrazzo |
| M42 | Wood block / composition block / mosaic parquet flooring |
| M50 | Rubber / plastics / cork / lino / carpet tiling / sheeting |
| M51 | Edge fixed carpeting |
| M52 | Decorative papers / fabrics |
| M60 | Painting / clear finishing |
| M61 | Intumescent coatings for fire protection of steelwork |
| N10 | General fixtures / furnishings / equipment |
| N11 | Domestic kitchen fittings, furnishings and equipment |
| N12 | Commercial catering fittings, furnishings and equipment |
| N13 | Sanitary appliances and fittings |
| N14 | General internal signage systems |
| N15 | Internal fire and safety signage systems |
| N16 | Bird and vermin control systems |
| N17 | Portable fire fighting systems |
| N25 | Permanent access and safety equipment |
| N91 | External signage and interpretation |
| P10 | Sundry insulation / proofing work |
| P11 | Foamed / fibre / bead cavity wall insulation |
| P12 | Fire stopping systems |
| P20 | Unframed isolated trims / skirtings / sundry items |
| P21 | Door / window ironmongery |
| P30 | Trenches, pipeways and pits for buried engineering services |
| P31 | Holes, chases, covers and supports for services |
Q: Paving / planting / fencing / site furniture
| Q10 | Kerbs / edgings / channels / paving accessories |
| Q20 | Granular sub-bases to roads / pavings |
| Q21 | In situ concrete roads / pavings / bases |
| Q22 | Asphalt roads / pavings |
| Q23 | Gravel / hoggin / woodchip / resin bound roads / pavings / overlays |
| Q24 | Interlocking brick / block roads / pavings |
| Q25 | Slab / brick / sett / cobble pavings |
| Q26 | Special surfacings / pavings for sport / general amenity |
| Q28 | Topsoil and soil ameliorants |
| Q30 | Seeding / turfing |
| Q31 | External planting |
| Q32 | Internal and artificial planting |
| Q35 | Landscape maintenance |
| Q37 | Green roofs |
| Q40 | Fencing |
| Q41 | Barriers / guardrails |
| Q50 | Site / street furniture / equipment |
| Q52 | Play and sports equipment |
| Q55 | External decks, boardwalks and bridges |
| R10 | Rainwater drainage systems |
| R11 | Above ground foul drainage systems |
| R12 | Below ground drainage systems |
| R13 | Land drainage |
| R16 | Groundwater pressure relief drainage |
| R17 | Soakaway, septic tank and sewage treatment units |
| R18 | Pumping stations and pressure pipelines |
| S14 | Irrigation |
| S15 | Fountains / water features |
| S17 | Water reclamation systems |
| S90 | Hot and cold water supply systems - domestic |
| S91 | Natural gas supply systems - domestic |
| S92 | Sprinkler systems - domestic |
T: Mechanical heating / cooling / refrigeration systems
| T90 | Heating systems - domestic |
U: Ventilation / air conditioning systems
| U90 | General ventilation - domestic |
V: Electrical supply / power / lighting systems
| V90 | Electrical systems - domestic |
| V91 | Electrical systems - landscape |
W: Communications / security / control systems
| W53 | Assistance call systems |
| W90 | Communications and security systems - domestic |
| X12 | Vertical platform lift systems |
| X13 | Inclined stairlift systems |
Z: Building fabric reference specification
| Z10 | Purpose made joinery |
| Z11 | Purpose made metalwork |
| Z12 | Preservative / fire retardant treatment |
| Z20 | Fixings and adhesives |
| Z21 | Mortars |
| Z22 | Sealants |
| Z31 | Powder coatings |
| Z33 | Anodizing |
[edit] Related articles on Designing Buildings Wiki
- Bills of quantities.
- BIM classification.
- Classification systems.
- Common arrangement of work sections.
- Comparison of SMM7 with NRM2.
- Construction Project Information Committee.
- Elemental cost plan.
- How to take off construction works.
- New Rules of Measurement.
- Preliminaries.
- Production information.
- Specifications.
- Standard Method of Measurement (SMM7).
- Uniclass.
Featured articles and news
Reslating an ancient water mill
A rare opportunity to record, study and repair early vernacular roofs.
CIOB Apprentice of the Year 2025/26
Construction apprentice from Lincoln Mia Owen wins this years title.
Insulation solutions with less waste for a circular economy
Rob Firman, Technical and Specification Manager, Polyfoam XPS explains.
Recycled waste plastic in construction
Hierarchy, prevention to disposal, plastic types and approaches.
UK Net Zero Carbon Buildings Standard V1 published
Free-to-access technical standard to enable robust proof of a decarbonising built environment.
Prostate Cancer Awareness Month
Why talking about prostate cancer matters in construction.
The Architectural Technology podcast: Where it's AT
Catch up for free, subscribe and share with your network.
The Association of Consultant Architects recap
A reintroduction and recap of ACA President; Patrick Inglis' Autumn update.
The Home Energy Model and its wrappers
From SAP to HEM, EPC for MEES and FHS assessment wrappers.
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.
Planning reform: draft NPPF and industry responses.
Last chance to comment on proposed changes to the NPPF.
A Regency palace of colour and sensation. Book review.