6.1 UNFORESEEABLE PHYSICAL CONDITIONS IN THE SILVER BOOK, THE CONTRA...
In the Silver Book, the contractor bears the risk of unforeseen difficulties
unless this is otherwise stated in the contract. By clause 4.12, unless the con-
tract states otherwise:
●
the contractor is to be taken to have obtained all necessary information as
to risks, contingencies and other circumstances which may influence or
affect the works;
●
by signing the contract the contractor accepts total responsibility for having
foreseen all difficulties and costs of successfully completing the works; and
●
the contract price is not to be adjusted to take account of any unforeseen
difficulties or costs.
The risk borne by the contractor here is therefore total, unless the contract
(by the particular conditions) expressly permits an additional payment.
Equally, the contractor is not permitted an extension to the contract comple-
tion date if he encounters physical difficulties (clause 8.4). By contrast, under
clause 4.12 of the Yellow and Red Books, the contractor could obtain an
extension of time and additional payment (cost but not profit) if he encoun-
ters physical conditions which were unforeseeable in the sense that no
experienced contractor at the date of tender could reasonably be expected to
have foreseen them. He is also permitted an extension of time by clause 8.4.