(a) The proceeds derived from the sale of any bonds (other than refunding bonds) may be used only to pay the cost of acquiring, constructing, improving, enlarging and equipping the project with respect to which they were issued as may be specified in the proceedings in which the bonds are authorized to be issued.
(b) Such cost, which shall be paid from the proceeds derived from the sale of bonds, shall be deemed to include the following:
(1) The cost of any land forming a part of the project;
(2) The costs of the labor, materials and supplies used in any such construction, improvement or enlargement, including architect's and engineer's fees and the cost of preparing contract documents and advertising for bids;
(3) The purchase price of and the cost of installing equipment for the project;
(4) The cost of landscaping the lands forming a part of the project and of constructing and installing roads, sidewalks, curbs, gutters, utilities and parking places in connection therewith;
(5) Legal, fiscal and recording fees and expenses incurred in connection with the authorization, sale and issuance of the bonds issued in connection with such project; and,
(6) Interest on said bonds for a reasonable period prior to and during the time required for such construction and equipment.
(c) If any of the proceeds derived from the sale of said bonds remains undisbursed after completion of such work and payment of all of the said costs and expenses, such balance shall be used for retirement of the principal of bonds of the same issue.