476. Person liable to pay.

An architect or engineer is ordinarily employed by the building owner, and has to look to him for payment1.

Where the building contract gives power to vary the works specified, and provides that additions or omissions due to such variations are to be measured by the architect so as to ascertain the amount to be added to or deducted from the contract price, the building owner may be liable to pay the architect for this service, if it falls outside the architect's original engagement and the building owner is aware that it is an additional service