QUOTE(Critical_Fallacy @ Oct 21 2014, 12:35 AM)
Just wondering...
(1) Is the Contractor liable for design produced by a nominated sub-contractor?
(2) If the Architect’s design is faulty, but the Contractor builds it badly, who is liable?
(3) Say a contractor, working under a PAM'98 contract, knows broadly what is required, but does not have drawings or specification which shows precisely what is required. So, the contractor thinks it knows what to do and carries on with the work to its own detail. Subsequently, the detail fails with serious consequences. For example, it might be a badly constructed roof detail, an inadequate stanchion base or perhaps wrongly positioned heating pipes. Is the Contractor liable for something done on its own initiative?
good question

(1)
there are 2 type of subcontractor namely domestic subcontractor and nominated subcontractor. main contractor have direct contractual relationship with them so if any of them in default, main contractor will have to be liable because after all they are main contractor's baby. the differences is that when nominated subcontractor in default, main contractor can claim those damages against employer if nominated subcontractor not capable of remedy the damages. the reason is because there is a collateral warranty between employer and nominated subcontractor and hence privity of contract established simply because of employer selecting the nominated subcontractor.
but for domestic subcontractor side, main contractor cannot indemnify against employer for all the fault due to the DSC as appointing of DSC is nothing to do v employer.
(2)
Architect. provided u can prove that his design is not workable. there is 1 term called Frustration in contractual term. refer wiki link abt what is frustration
http://en.wikipedia.org/wiki/Frustration_of_purposeQUOTE
In the law of contracts, frustration of purpose is a defense to enforcement of the contract. Frustration of purpose occurs when an unforeseen event undermines a party's principal purpose for entering into a contract, and both parties knew of this principal purpose at the time the contract was made. Despite frequently arising as a result of government action, any third party (or even nature) can frustrate a contracting party's primary purpose for entering into the contract. This concept is also called commercial frustration.
example of frustration is let's say suddenly government announce that material "x" is banned, then it's a frustration that not due to contractor fault.
however if it was proven it's self-induced frustration, then it contractor own fault. this mean the frustration happen due to contractor incompetence. it's duty of contractor to raise up the issue during tender stage. when u accepted the condition during tender stage, u deems to accepting that it's workable.
(3)
yes. u know a term called "silence in golden", apply here so nicely

contractor have to request information from consultant when it have no detail. contractor shouldn't take risk propose own thing without seeking approval. after all, if consultant delay in giving information, detail, it is contractor right to claim for extension of time and hence u got loss and expenses due to prolongation.