Smaller projects

5. Specification for smaller projects

5.1 Schedules of work

5.1.1 Introduction

Section 3.3.3 'Smaller projects' describes the use of the schedule of work, supported by a reference specification, forming a two-part project specification. Information that is priceable and variable project to project should be included in the schedule of work or the preliminaries. Statements of quality and workmanship that are deemed to be of general good practice, not varying project to project, should be included in the reference specification.

The schedule of work, reference specification and drawings should be structured and drafted to form a single set of co-ordinated production information. The documents should provide clear, comprehensive and unambiguous information that will allow the construction works to be completed efficiently.

The main difference between a specification (as discussed in Section 4) and a schedule of work is that the latter also functions as the pricing document. The structure of the schedule of work should reflect the needs of both specifier and constructor for pricing and valuation in addition to construction and quality control.

5.1.2 Work items

As a rule, the more detailed the level of pricing, the more precise the process of estimating and valuation of variations. The schedule of work should therefore identify and describe each and every price-significant item of finished work. Each such work item should be:

• Carried out by a single 'trade' (in practice, restricted to a single CAWS section), in one operation.
• Cross-referenced to the relevant section of the reference specification (which should be arranged by CAWS).
• Succinct yet sufficiently complete for accurate pricing, normally without the need for constant reference to the reference specification.
• Capable of being measured by the constructor, by correlation with either the drawings (new work) or locations in the existing building. Where the extent of the work cannot be determined in advance an assumed quantity, subject to adjustment, should be given.

Work items will need to specify attributes or properties, which should be given as sub-items. In specifying the attributes it is important to minimise repetition, e.g.:

• Defining common attributes of some types of work and scheduling the differences. For example, the proprietary brand and finish of kitchen units can be identified as common attributes, the type, size, etc. of the fittings being given separately.
• If an identical or near identical work item containing a significant amount of text is included in different constructions, it should not be repeated. A cross-reference should be given, with details of any differences.

5.1.3 Constructions

Constructions consist of work items, grouped together to define clearly recognisable parts of the building (either whole elements or parts of elements) or locations of the building (e.g. repair/renewal work in a certain room). They are cost significant in that they provide a context to aid visualisation of the work involved, and form a price collection structure for the work items. The nature of the constructions and their arrangement will be determined by the nature of the work, particularly whether it is new build or alterations:

Alteration work

The constructor will need to visit the site to assess the work and take dimensions. The constructions should therefore be formulated and arranged by location, room-by-room and elevation-by-elevation (see Figure 5.1). Cross-referencing to previous similar items will avoid excessive repetition of descriptions occurring in several locations.

Figure 5.1 Example construction for alteration work

New work

The constructor will need to correlate the descriptions with the drawings to assess the context and take dimensions. The constructions should therefore be formulated and arranged by elements, as in Figure 5.2. This will allow groups of like types of work to be brought together, significantly reducing the size of the document.

Upper floors
130 Softwood boarding on joists
Timber board flooring (K20) Edges: Tongue and grooved. Species: European redwood. Finished face width: 137 mm. Finished thickness: 21 mm. Moisture content at time of fixing: 9 to 13%. Fixing: 50 mm steel oval brad head nails. Softwood floor joists (G20) Cross section size: 47 x 195 mm regularized. Strength class: C16. Joist centres: 400 mm. Preservative treatment: CCA to BWPDA Commodity Specification C8. Fixing: Joist hangers. Other requirements: Double joists below bath. See drawings. Joist hangers (G20) Type: To BS 6178-1. Material: Galvanized steel. Fixing: Built in. Solid softwood strutting at partition positions (G20) Cross section size: As floor joists. Location: As drawings. Fixing: Galvanized mild steel framing anchors. Softwood herringbone strutting between floor joists (G20) Cross section size: 38 x 38 mm. Location: As drawings. Outer joists: Use solid blocking to perimeter walls. Fixing: Skew nail to floor joists. Softwood noggings (G20) Cross section size: 50 x 75 mm. Locations: Where required for bracing, appliances, sheet edges and the like. Fixings: Skew nail. Lateral restraint straps (G20) Type: Cranked end. Material: Hot dip galvanized mild steel, minimum coating 260 gm/m². Length: 150 mm cranked end x 1050 mm long. Cross Section: Not less than 30 x 5 mm. Centres: Not more than 2000 mm. Location of straps: Top of joists. Bracing of joists parallel to wall: Notch joists. Brace with tightly fitted packing and solid softwood strutting 38 mm x two thirds depth of joist (minimum). Fixing: Not less than four 50 mm x 8 gauge sherardized countersunk screws per strap.
Total for softwood boarding on joists

Figure 5.2 Example construction for new work

The tendering constructor has the option of pricing each work item or, where the quantity is small and to save time, the whole construction as one lump sum.

Projects may contain both new and alteration work, in which case the schedule of work may, if considered appropriate, be divided into two such parts, starting with the work to existing and followed by the elementally based sections for new work.

Organisation of the schedule of work into constructions arranged by elements and/or locations will facilitate:

• Cost adjustment by negotiation at tender stage.
• Construction planning, ordering of products and quality control.
• Valuation of variations.
• Valuations for interim certificates.

5.1.4 Linking the drawings to the schedule of work

Linking between the drawings and schedule of work should operate as follows:

• During construction, the 'lead' document is likely to be the drawings. The constructor will need to link each piece of work shown on the drawings to the relevant construction in the schedule of work to establish what is required. Each construction should therefore be the subject of a cross-reference from the drawings to the relevant number and heading in the schedule of work, e.g.:

  470 Opening in existing cavity wall (see Figure 5.1)

  130 Softwood boarding on joists (see Figure 5.2)

• During pricing, the 'lead' document is likely to be the schedule of work. The constructor will need to link each construction to the drawings. Arrangement of the schedule of work by elements (new work) or locations (alteration work) will facilitate this. The cross-references to the schedule of work will confirm to the estimator that he has located the correct items on the drawings.

To ensure that the construction reference numbers and headings on the drawings are given correctly they should be copied and pasted from the schedule of work. The annotations on the drawings should not duplicate other information contained within the schedule of work.

Appendix S3 gives an example annotated drawing, related schedule of work constructions, and a related section of reference specification.

5.1.5 Location information

Section 3.1.2 discussed location information schedules, traditionally regarded as drawings, and proposed that they can and should now be regarded as part of the specification. Section 4.1.4 discussed location information on larger projects.

On smaller projects where a schedule of work is used, the use of drawn location schedules introduces the risk of duplicating the pricing of the work and also the possibility of conflicting description. For example, where a schedule of work priced work item includes the size of a door, to also include the size in a separate location schedule may give rise to a discrepancy. The use of location information schedules is therefore generally best avoided on smaller projects. Where they are used a consistent approach should be followed that provides the information in one place only: the location schedule should not duplicate the descriptive and pricing functions of the schedule of work.

Schedules of work arranged by elements

The combinations of specification variant that occur on the project are analysed, and the various 'types' are defined, e.g. the door leaf types, doorframe types, ironmongery 'set' types, etc. To avoid or minimise repetition each type of door leaf, doorframe, ironmongery set, etc is fully described in one priceable work item within the relevant elemental section of the schedule of work (in this example Doors) with references to the relevant door numbers, see Figure 5.3:

TYPE 1 INTERNAL TIMBER DOORFRAMES: Location: Doors 2, 3, 4, 6, 8, 9 and 14 Frame and architraves: as Drawing A/202 Timber species: European whitewood Preservative treatment: not required Moisture content on delivery: 10 to 14% Finish as delivered: primed for painting Fixing: plugged and screwed TYPE 2 INTERNAL TIMBER DOORFRAMES: Location: Doors 1, 7 and 12 As Type 1 but as Drawing A/203 (etc)

Figure 5.3 Work items giving location information

On simple projects this information may be sufficient, but if the project is complex a locational schedule can be provided for use during construction, summarising the way in which the types combine - see Figure 5.4. The same principle can be applied to other common types of location schedule, e.g. internal finishes.

DOOR SCHEDULE (Information provided for convenience during construction, and not priceable – work items for pricing are given elsewhere) DOORS 2, 3, 4, 9 and 14: Frame type 1 Door leaf type 4 Ironmongery set type 7 Lintel type 3 DOORS 6 and 8: (etc)

Figure 5.4 Location schedule for use with complex information

Schedules of work arranged by locations

Each type of work should be fully specified in the first occurring location, e.g. Room 1, Door 1, etc. Subsequent rooms, doors, etc can then be specified at least partly by back reference - see Figure 5.5. In this way each location can be given for separate pricing, without incurring excessive repetition. Where the schedule of work is arranged by locations in this way separate location schedules will obviously be unnecessary.

DOOR 6: Softwood frame as Door 1 Veneered door leaf as Door 3 Ironmongery: - Pair of 75mm satin stainless steel butt hinges - Mortice lock, Union 2234 Sashlock, satin stainless steel face, 3 keys - Lever handles, satin stainless steel, round bar style with return end, rectangular backplates with rounded corners, keyholes - Kicking plate one side, satin stainless steel, 150 mm high, screw fixed - Lintel as Door 1

Figure 5.5 Work item for a particular location