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Last edited 03 Apr 2019
Sub-contractors are appointed by main contractors to carry out part of the works on their behalf. As construction has become more complicated and more specialist construction techniques have been developed, it has become increasingly common for contractors to sub-contract others rather than employing a large workforce themselves.
The use of sub-contractors enables the main contractor to undertake more complex projects whilst not unacceptably increasing their risk, however, concerns have been expressed about the prevalence of sub-contractors because of a perception that the main contractor has less control over the skills and training of sub-contractor employees and so there may be a negative impact on quality and health and safety on site.
Sub-contractors can be classified as:
In addition, on management contracts the works will be carried out by 'works contractors' and on construction management contracts the works will be carried out by 'trade contractors', although technically trade contractors are not sub-contractors as they are contracted by the client, and only managed by the construction manager.
A domestic sub-contractor is any sub-contractor, other than a nominated-sub contractor, that the main contractor sub-contracts to carry out part of the works. The work of the sub-contractor is the responsibility of the main contractor as far as the contract between the main contractor and the client is concerned.
A sub-contractor can be considered domestic if:
- They were freely selected by the contractor.
- They were selected by the contractor from a list of at least three possible sub-contractors.
There can be uncertainty about whether a sub-contractor is domestic or is nominated, where for example, the contractor is free to select from a list, but it transpires that only one of the sub-contractors named on the list is actually capable of carrying out the works required.
 Find out more
 Related articles on Designing Buildings Wiki
- Collaborative practices.
- Construction supply chain payment charter.
- Fair payment practices.
- Named sub-contractors.
- Nominated sub-contractors.
- Selected subcontractor.
- Specialist contractor.
- Specialist designer.
- Trade contractor.
- Works contractor.
 External references
- Building article:What sort of subbie are you?
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