The licensing agency shall make or cause to be made such inspections and investigations as it deems necessary. The licensing agency may prescribe by regulations that any licensee or applicant desiring to make specified types of alteration or addition to its facilities or to construct new facilities shall before commencing such alteration, addition or new construction, submit plans and specifications therefor to the licensing agency for preliminary inspection and approval or recommendations with respect to compliance with the regulations and standards herein authorized. Necessary conferences and consultations may be provided.