Prior to the acquisition of title to any real property an Authority shall submit to the Department data as to the location and cost of the property, and prior to the undertaking of any construction or other initiation of a project an Authority shall submit to the Department the proposed plans, specifications and estimates of the costs and a statement of the proposed methods of financing and operating the project. An Authority shall not finally acquire title to any real estate nor undertake the construction or operation of a project without the approval of the Department; provided that, if the Department shall fail within thirty days after receipt thereof to state its disapproval of the proposals or such modifications thereof as it may deem desirable, the proposals shall be deemed to have been approved as submitted. No change involving an expenditure of more than twenty-five hundred dollars ($2500) shall be made in any proposal approved by the Department without submission to the Department in the manner prescribed in this Section. The provisions of this Section shall not apply with reference to any project which is or is to be financed in whole or in part by the federal government or any agency or instrumentality thereof or undertaken pursuant to the additional powers conferred in Section 8.2 upon housing authorities in any municipality or county having a population in excess of 1,000,000.