Any insurance company of this state authorized to hold, purchase and convey real estate may present to the governing body of any city of the first class in this state an application for approval of a project for the acquisition of a tract of real estate in the city occupied in whole or in part by insanitary or unsafe structures used as dwellings, for the demolition of the existing structures and for the construction upon the tract of new housing facilities in accordance with proper standards of sanitation and safety, at the expense of the applicant. The application shall set forth a statement of the project presented for approval, to which shall be annexed the following exhibits:

a. A map showing the location of the tract and of the structures thereon, the acquisition of which is deemed by the applicant to be necessary to the project.

b. A plan and specifications prepared by an architect or engineer showing the new housing facilities to be constructed upon the tract pursuant to the project, which may provide stores and offices on the ground floor.

c. An estimate of the cost of the entire project prepared by an architect or engineer.

d. An estimate of the rentals of the new housing facilities necessary to assure a return of five per cent upon the cost of the entire project after payment of all taxes, insurance, costs of operation and maintenance and an annual amount sufficient to amortize the entire cost of construction of the new housing facilities at the end of a period of twenty years from their completion.

At any time prior to the final action of the governing body upon the application, the applicant may in its discretion amend or supplement the application in such manner as it desires to conform to the conditions the governing body may impose upon the granting of its approval.