An element of excavation in rock was undertaken by the Contractor, which was measured as the amount of rock removed. The PM reduced the measure stating that it should only have been measured to the lines & levels indicated on the drawing and that overbreak should have been included in the rate. After two months it was conceded that the existing bill rate wasn’t the correct rate, and an instruction asking for a revised rate was issued.
Reading in Glenn’s article 31st July 2015, as it is a new rate it should not have been programmed, so any time taken carrying out the works should form part of the CE.
My question is: if the PM instructed the new rate, but due to delay by both parties, it wasn’t instructed until after that element of work was completed, at which point should the PM have instructed the rate? Should it be: when the works were started, as this point would render the bill rate inadequate; or when it was decided by the Contractor the original rate wasn’t relevant; or when the PM agreed there should be a new rate; or is it the date of the issued instruction; or another date, because the original bill was always incorrect?
The relevance of the date being for the calculation of delay.