All architectural, engineering or site development plans for housing projects constructed under the provisions of this act shall be approved by the department or its duly accredited representatives before the work covered by the plans is undertaken.

Standards as to materials and construction techniques shall be as specified or approved by the department and must conform to requirements of local codes.

The department or its duly accredited representatives shall be allowed full access at reasonable times to every housing project initiated under the provisions of this act so as to permit a free inspection of materials, methods of construction, and standards of maintenance as required under the provisions of the contract.