The specification sets out the works in detail. It contains a description of the nature and quality of the works and the required workmanship. It is usually read in conjunction with drawings and bills of quantities. Together they should furnish sufficient evidence to define the works.
The specification should include on-site facilities and general information about the project, availability of services, means of access and special issues not otherwise referred to in the contract. Method statements may be provided in the specifications to elaborate on clauses in the contract.
The specifications commonly describe the nature and quality of the materials and workmanship. Briefer details are included in the bill of quantities.
Tender drawings may be prepared prior to specifications. The specification may be derived from the drawings.
Engineering specifications should include information in relation to soil conditions and site surveys. The tenderers may be invited or allowed to inspect and make soil investigations.
Any particular requirements are included in the general part of the specifications. The employer may have special needs and requirements which are incorporated. For example, there may be a requirement for part of the works to be completed early. The specifications may require that the works comply with EU, Irish or British standards.
General requirements may include descriptions of the work, particulars of the existing worksite location, access issues, lists of contract drawings, quality assurance, soil investigations, particulars of engineers, photographs, site records, attendances on trades, safety, legal provisions, general matters.
The standards and sample section deals with standards of goods and materials. It may state the standards with which the materials must comply. They might be specified to comply with standards such as ISBS or CE standards, unless and to the extent varied by the bill of quantities.
Tolerances may be specified. There may be requirements for submission of samples to engineers whose approval may be required. The contractor undertakes to comply with approved samples.
The specifications will cover materials and workmanship. Work may be divided into different sections and aspects such as earthworks, dredging, concrete, drainage and road works. The material and workmanship clauses for each may be set out.
An alternative approach is for materials required to be set out in one section followed by another, dealing with the workmanship, divided into subsections of work. The materials and workmanship should specify the quality of materials and the standard of workmanship for the works.
Categories of works may be listed including, for example, excavation and earthworks, piping and drains, concrete and reinforced concrete and steelwork. Each section will cover a wider subcategory of issues and matters to be dealt with.
For example, there may be provision for suitable materials for soil, such as topsoil, suitable material, and unsuitable materials, materials for backfill, use of topsoil, removal of unsuitable materials, disposal of surplus material from the site, reuse of material, fill, and compaction of fill. There may be provisions for concrete and reinforced concrete. It may deal with particulars of cement, aggregate storage, mixing, curing concrete, reinforcement, finish, etc.
Bill of Quantities
The bill of quantities in a measurement contract describes the items of works required and the quantities for each. It is priced as part of the tender. Tenderers insert the relevant rates or prices for each item. The fully priced bill is the basis of a tender.
The bill of quantities forms part of the contract. Civil engineering uses the method of measurement provided by the Civil Engineering Standard Method of Measurement. The Institute of Civil Engineers has published the Standard Method of Measurement of civil engineering quantities for many years.
The bill is required to contain a list of the principal quantities in accordance with the CESMM. This comprised the principal components of the works and approximate quantities. It is a general summary to allow the tenderers to rapidly assess the general scale and extent of the works prior to examination of the full details of the tender.
Standards Methods of Measurement
The CESMM comprises definitions, general principles, application of work classification, coding and numbering of items, preparation of the bill of quantities, computing of pricing of the bills or quantities by a tenderer, method-related charges and works classification.
The general principles set out principles for the application of the more detailed rules. The application of the classification deals with units of measurement, coding and the manner in which codes are assigned to items in the bill.
The CESMM provides rules for the preparation of the bills, dealing with elements to be included, such as day work, prime cost item, provisional sums and units of measurement. The CESMM provides for the manner in which the bills of quantities are to be completed and priced by tenderers.
The work classification divides works into classes that are coded. Each class contains a statement of inclusion, exclusions, a classification table and rules.
The classes of work covered include general items, site investigation, geotechnical and specialist processes, demolition and site clearance, earthworks, in-situ concrete, precast concrete, various aspects of pipework, structural metalwork, timber, piles, roads and paving, rail track, tunnels, brickwork, painting, waterproofing, sewer renovation and ancillary works.
The preamble for the bill sets out instructions and the obligations imposed by the document, which is to be the basis of tender. The purpose is to assist the tenderer in pricing items unambiguously. It assists the engineer in applying uniform criteria for the measurement of quantities during the execution of the contract.
The preamble may direct attention to the form of contract, conditions, specification and drawings which are to be read in conjunction with the bills. It is usually confirmed that it is drawn up in accordance with the standard method of measurement of civil engineering quantities. It confirms the price or rate is to be entered against each item in the bill, whether quantities are stated or not.
Special methods of measurement used are stated at the head or in the text of the bill of quantities for the trades or items concerned. Other items are measured net in accordance with drawings. General directions and descriptions of work and material given in the specifications are not necessarily repeated in the bill.
The preamble may also cover
- programming and execution of work by nominated subcontractors,
- provisional sums and PC items;
- content of the work to be included and percentage quoted for an adjustment of provisional sums envisaged to be executed by nominated subcontractors or suppliers;
- classification of the basis of payments for various items.
The prices and rates to be inserted in the bill are to be the full inclusive value of the work including all costs and expenses required in connection with the construction of the work. This includes general risks, liabilities, and obligations set out or implied in the documents on which the tender is based.
The pricing sections of the bills are made up of lists of items identifying descriptions and estimated quantities of works envisaged under the contract. The tenderer is to set out its rate for each item. The rates and quantities make up the tender price.
The rates provided are to apply in the absence of genuine errors recognised as such by the engineer prior to the contract. Some of the items may be quoted as a lump sum together with provisional sums for items that are not defined.
If the CESMM applies, the section for inclusion of preliminaries is not necessary. The bill may contain, even if prepared in accordance with CESMM, items usually included as preliminaries to be listed and priced in the general items.
The bill is comprised principally of work items which are grouped into parts. They follow the scheme of the works. There should be a logical pattern referable to the nature of the work.
General items include preliminary items, earlier included in the preliminaries bill. The section may include items for general obligations, site services, temporary works, testing, provisional sums and prime cost items. They are parts that are not proportional to the quantities of the works undertaken.
The standard contract allows the engineer to order additional works or substituted works on a day work basis if it is considered necessary or desirable to do so. This is work that is incidental to the contract. The contractor is paid on a day work basis under the day work scheduled in the bill of quantities at the rates and prices set out in the tender. If there is no day work schedule, it is paid under the rates and prices contained in the scheduled of day works issued by the Federation of Civil Engineering Contractors.
Provisional and Prime Costs Sums
Provisional sum items are provided in the bills for contingencies, additional or extra works, or for the cost of works envisaged to be carried out or works that are to be carried out by nominated subcontractors. They arise only at the direction and discretion of the engineer. Work is measured and valued at the rates contained in the priced bills, as a prime cost item or on the basis of day works.
Provisional items are marked as such in the bill of quantities. They are items that may or may not be required. There may be eventualities or contingencies that may arise in the work such as those arising from the site conditions.
The general summary of the bill of quantities tabulates the various parts and totals brought forward. A provisional sum for contingencies may be required to be included. The tender total is the aggregate of amounts tendered for each part which are tabulated in the summary. The tender total is the total of the priced bill at the date of acceptance.
Prime cost sums are the net sum entered in the bill of quantities to cover the cost to be paid by the contractor to third parties for articles and materials to be supplied or work done. When they are entered in the bill of quantities, the tenderer is to be allowed complete sub-items for charges and profits on prime cost as a percentage and for handling and fixing connected with the item for which the prime cost is intended.
The tenderer is to compute the amount derived by the percentage quoted by him to the prime cost sum. The amount payable is to be the actual cost of the item for which the prime cost is intended plus the percentage quoted by the tenderer of the actual cost plus the fixed sum for the handling and fixed element of the prime cost sum.