No lot in a subdivision may be sold, no permit to build, alter or repair any building on land in a subdivision or land development may be issued and no buildings may be erected in a subdivision or land development until a final subdivision or land development plan has been approved by the Borough Planning Commission and the Borough Council and, where required, improvements have been completed or their completion has been assured by the execution of a performance guaranty pursuant to §
184-18 herein or by the deposit in escrow of funds or securities sufficient to cover the cost of the required improvements as estimated by the Borough Engineer, and furthermore that the structural integrity of the improvements and the functioning of the improvements in accordance with the design and specifications has been assured by the execution of a maintenance guaranty pursuant to §
184-56 herein.