The difference between a prime cost sum and a provisional sum
Confusion can arise regarding two items that may appear in standard forms of building contract – prime cost sums (PC or PC sums) and provisional sums (PS). They both relate to estimates made for certain costs in the absence of exact figures.
A prime cost sum is an allowance, usually calculated by the cost consultant, for the supply of work or materials to be provided by a sub-contractor or supplier that will be nominated by the client - that is, a supplier that is selected by the client to carry out an element of the works and imposed on the main contractor after the main contractor has been appointed.
The main contractor is entitled to add mark up and attendance costs to the allowance. If the main contractor's actual costs then turn out to be higher, the contract sum is increased, and if the main contractor's actual cost is lower, the contract sum is reduced.
For more information see: Prime cost sum.
A provisional sum is an allowance, usually estimated by a cost consultant, for a specific element of the works that is not yet defined in enough detail for tenderers to accurately price.
Depending on the degree to which the works that the provisional sum relates to can be described at the tender stage, prime cost sums may be referred to as 'defined' or 'undefined'.
For more information see: Provisional sum.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Which room is the most fun to design? Find out the 'Grand Designs' presenter's unusual choice in our interview.
Full suite of speakers are announced for this year's BSRIA Briefing event.
Book your place for the Architectural Technology Awards 2018.
There are many ways of classifying types of building. Have a look at our range of building articles.
BSRIA have launched the 'major update' of the go-to design framework guide for building services.
How to get results with building life cycle assessment.
Government publishes a prospectus inviting proposals for new 'garden communities'.
The Morandi motorway bridge in Genoa collapses during rainstorm while undergoing maintenance works.
'Developed design' is a phrase coined by the RIBA for their 2013 Plan of Work. But what does it actually mean?
New green paper published aiming to rebalance the relationship between landlords and residents and tackle stigma.
RIBA calls for a comprehensive ban on combustible materials.
Comments
Is PC for a specific element? It seems that it does not match the Home Building Contract?
It is for a specific element of the works. This is a term used in the UK, it may be that definitions / contract terms are different in other countries.