Unless a contract for the construction or alteration of an essential services building is entered into prior to July 1, 1986, before adopting any drawings or specifications for the essential services building, the governing board, authority, owner, corporation, or other agency proposing to construct any essential services building shall submit the design calculations, drawings, and specifications of the essential services buildings to the appropriate enforcement agency. The enforcement agency shall stamp the drawings and specifications if the construction or alteration is approved by the enforcement agency. Included with the stamp shall be the signature of the qualified person referred to in Section 16018 or Section 16019.