10. The contractor must see to it that the construction work on a building is carried out in conformity with the regulations under this Act.
He must, in addition, at or before the time of delivery of the building, transmit to the owner a written statement certifying that the work has been executed in conformity(1) with the regulations, where the plans and specifications were not prepared by an architect or an engineer, or
(2) with the plans and specifications, where they were prepared by an architect or an engineer, if the architect or engineer was not responsible for supervising the work.