It is very unusual for a contractor to undertake all the work in a contract with their own workforce. Even in minor construction projects the main contractor is likely to require the assistance of a trade or specialist firm. Work undertaken by firms other than the main contractor are described as sub-contractors, although it is not uncommon to find specialist firms working on site beyond the normal jurisdiction and control of the main contractor, and consequently, not a sub-contractor within the generally understood description.
Employers may employ these firms directly and as such they are not to be considered as sub-contractors of the main contractor. Provision is made within the contract so that such firms have access to the site and any facilities.
The employer may also nominate particular firms for specific work that will be required. This approach is used if the employer wants a greater control over the sub-contractor: Although after nomination they are often treated like one of the main contractors own sub-contractors.
The architect may also name sub-contractors in the BofQ, who will be acceptable for the execution of some of the measured work. This procedure avoids the lengthy process of nomination, but still provides a measure of control on the part of the architect. The requirement under JCT is to name at least three firms who would be acceptable by the architect. This allows for an element of competition and allows the main contractor to select the firm. The contractor can also add to the list subject to the approval of the architect.
In addition work can be carried out by sub-contractors who are selected by the main contractor these are referred to as domestic sub-contractors. Selection of Sub-contractors Sub-contractors should be selected, not only on price, but also:
- Business integrity
- Guarantee of service
- Quality of workmanship
- Ability to meet the programmed completion date
- Financial stability
- Attendance required with regard to facilities, unloading and handling of materials
- Ensure a proper understanding of the terms and conditions of the contract.
Control and Coordination of Subcontractors
It is the main contractor who is responsible for the control and coordination of the subcontractors. Subcontractors will need to fit in with the main programme in order to ensure that they are available when required; failure to do this can have an adverse effect on the programme and can affect the completion of the contract. It is important therefore, that the subcontractor is involved at the planning stage in order to ensure that they are available when required and are aware of the requirements relating to the contract. Chapter 18 of the Cooke /Williams book should be read in relation to this.