I read Ann Minogue’s article regarding defined and undefined provisional sums with interest (3 December, page 49).
Her example of the reception desk was useful but I think slightly misleading as, in JCT98 footnote 10.3, it clearly stipulates that, among other things, the contractor has to be provided with “the nature and construction of the work”, for example, whether it is Italian granite or MDF. Failure to meet all the criteria in footnote 10.3 would mean the provisional sum is undefined.
The problem is that the people inserting provisional sums into tender documents (usually QSs like me) are oblivious to footnote 10.3 and often stipulate that a sum is defined when it is in fact undefined.
Unfortunately, the problem is not with the definitions but with the professionals who implement them!
Keith Curran, Gardiner & Theobald