Yes, on the classic wording: Leedsford Ltd v The City of Bradford held that a named supplier or other approved leaves the contractor no right to nominate a firm of its own choosing, so there is an absolute obligation to supply the named product unless the architect chooses to approve an alternative, and the architect need only act in good faith

Yes, on the classic wording. Leedsford Ltd v The City of Bradford held that a specification naming a supplier or other approved firm does not give the contractor an option to put forward any firm of its choice for approval. On those words the contractor agreed to supply the named stone unless both parties agreed some other; no substitute could be used except by mutual agreement; the contractor fulfilled the contract by providing the named stone whether the employer wanted it or not; and the architect could approve no other. There was an absolute obligation to supply the named product unless the architect chose to approve an alternative, so a contractor who found a cheaper equivalent could not recover the difference in cost when approval was refused. The architect was not bound to give reasons and needed only to act in good faith. A genuine right of substitution needs express wording, such as that approval of an equivalent will not be unreasonably withheld, and on public-sector contracts procurement rules restrict naming a single supplier, so the position may differ.