Responsibility for site conditions is often a source of heated discussion during the negotiation of construction contracts. Under MF/1 the relevant clause (5.7) is not as stringent on the Contractor as in many other contracts with a similar provision.
This is because it is an “unexpected” rather than an “unforeseen” conditions clause. So as long as the Contractor can show that the site conditions were neither reasonably ascertainable from an inspection of the site nor indicated in the contract or tender information, then they will be entitled to any costs incurred in dealing with “obstructions or hazards” during the works.
That said, Contractors should remember to notify the Engineer of any such “obstructions or hazards” before carrying out any work to overcome them and obtain the Engineer’s approval up-front. What happens if the Engineer delays in giving such an approval or refuses outright? Most likely, the Contractor has no entitlement to extra costs incurred before giving notice to the Engineer, so that’s one for Contractors to remember.