The Confusing World of Contractors


It may be that your construction project requires all and more of these different types of contractor, and some will work with sub-contractors and so on and so on. ​If you’re a building firm or construction company, managing contractors is a part of everyday life.  If you’re a business owner looking to build a new production facility, a food manufacturer looking to expand or refine its manufacturing processes, or a retail or leisure operator requiring refurbishment or refit of a large premises, would you have the time or knowledge to hire the right contractors for your specific project, keep them working to deadlines and manage them in accordance with legal health and safety regulations?  If the answer is no, you probably need the services of a construction management company.

Generally, a construction manager should be appointed early in the life of the project so they can add value by improving the cost and buildability of your proposals, as well advising you on the selection of trade contractors.  When Vitruvius takes on the construction management role, we prefer to be involved at the very start of a project so we can work with our client to ensure the construction project meets their business objectives into the future, not just their short term needs (see our case study on working with Cotteswold Dairy).  A construction manager acts as a consultant to the client, the services they provide might include:

  • Advising on the development of the brief
  • Advising on the procurement route.
  • Advising on professional appointments (such as architects).
  • Advising on the feasibility, interfaces, buildability, cost and programming of the design.
  • Acting as the principal contractor.
  • Cost planning and cost control.
  • Preparing a construction programme and defining methods of working on site.
  • Tendering trade contracts.
  • Managing and co-ordinating trade contracts, including acting as contract administrator, carrying out or co-ordinating inspections, issuing instructions and certificates etc.
  • Managing the site.
  • Chairing site progress meetings and preparing progress reports for the client.

Where more than one contractor is involved in a project and where the design has already been completed and approved by the client, a general contractor could well be appointed for the construction phase of the project but they may well sublet parts of the work to specialist or trade contractors. For example, if your development includes items such as lifts, escalators, refrigeration units, air conditioning or is a listed building you’ll need specialist contractors or trades people.  When Vitruvius took on the role of project and cost management of a new Anytime Fitness centre in Stroud, they appointed a leisure development specialist to ensure thee acoustic specification between the gym and the neighbouring cinema was correct and then addressed any issues. In order to appoint the right specialists with the experience and knowledge required for your project you’ll need to put together specification documents and hold a tender process where specialist services are procured and rates and deadlines agreed.  It’s useful to appoint this specialist knowledge before the supply contract has been tendered so it can be properly integrated into the overall design to prevent delays.  On publicly funded projects OJEU procurement rules may apply.  Again, a construction manager can help you with this process.

On a construction project, the works are divided into ‘packages’ which are then contracted to separate contractors.  These contractors are called Trade Contractors, rather than sub-contractors, because they are contracted directly by the client.  Trade Contractors can be appointed through a single stage procurement process or, pre-construction services can be separated out to make it a two-stage process.  The separate appointment of trade contractors should reduce the cost of contracts, as the management element is being provided by the construction manager. This is also useful as it can allow certain works such as piling or groundworks, which might be needed before the overall design is complete, to begin.

The use of sub-contractors enables the main contractor to undertake more complex projects without increasing their risk, however, the problem is, as more and more sub-contractors are used, the main contractor has no control over the skills and training of the sub contractor’s employees which could cause problems with standards of quality and health and safety on site.   

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 or selected from a list of at least 3 other possible sub-contractors.

Of course, where there are contractors there must be contracts, tender documentation, drawings, work schedules and bills of quantities which we’ll be looking at in depth in a blog over the coming weeks.

If you’re planning a major construction, refurbishment or re-fit and would like some advice, please give Vitruvius a call  +44 (0)1242 325 005  or contact us on 

Information for this blog has been taken from:

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