The construction phase of any building contract, self-build, conversion or renovation is not just an arbitrary period but should instead be the product of careful thought as to the sequencing of the project in the most efficient and economical way.  The time, cost and quality conundrum needs balancing so that there will be no more than the optimum number of contractors working on site at any one stage and that no-one is hanging around and waiting for either materials to arrive or other trades to have finished their work.

Professional programmers optimise their programmes based on the critical path which is a clear linear summary of all the activities which can only start after a proceeding stage has been fully completed; for example the roof tiler can only undertake his work once the carpenter has finished building the roof structure and also when the bricklayer has built the chimney stack.  Other activities, which initially do not sit on the critical path, may have some ‘float’ time between what is referred to as their earliest start date and their latest start date.  Well run and efficient contracts will manage these activities such that they balance their actual start dates in order to preserve cash flow and, at the same time, mitigate the risk of project over-runs.

Most people either choose to appoint a main contractor, or project manage the construction phase themselves. In this article we look at the financial benefits and considerations when appointing a main contractor.


Financial benefits of using a main contractor:

  1. You de-risk the process for you and your lender by having qualified professionals at the helm
  2. The responsibility for the project programme becomes your contractor, not yours
  3. You have the certainty of a fixed price (within reason)
  4. They will monitor spend – undertaking periodic valuations of on and off site works to determine ‘earned value’ and if the build is on, over, or under budget


Considerations when using a main contractor:

  • Ensure you agree a start and target end-date with your chosen contractor so both you have a clear timeline and delivery expectations
  • Ensure you make timely decisions concerning outstanding material specifications e.g. floor finishes, sanitary ware, paint colours etc. If you take a long time choosing, this will hold up other stages of the build. Talk to your contractor about when decisions need to be made so you have plenty of warning and can plan accordingly
  • Create a robust tender document to ensure the contractor is quoting on all areas of the build, conversion, renovation required
  • Keep an eye on what you are paying for and when, making sure this meets the schedule you expect
  • Ensure periodic build valuations are dated and certified so you have clear idea of what payments needs to be made, and your deadline
  • If you make changes to specifications once construction is in progress, this will change the price. Make sure you have a contingency fund/plan for these changes, and any unforeseen costs that may arise


Our next article explores self-project management, and we give 8 handy tips for keeping finances in check when your managing the construction phase yourself.

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This article was written by Tim Doherty, and originally published for Build It Magazine. Tim is the Director and Principal Surveyor at Dobanti Chartered Surveyors, a building surveyors based in Tunbridge Wells, Kent. Dobanti offers a wide range of property services Surveys, Build Project Management, Contractor Tender development and Construction Phase Management. Get in touch for more information, or read more online now. Further articles and blog posts can be found here.