11 Pa.C.S. § 11911: Contracts for improvements and assignment of assessments.

Where the whole or any part of the cost of an improvement is to be paid by assessments upon the property abutting or benefited, the city may enter into an agreement with the contractor pursuant to which the contractor shall take an assignment of the assessments in payment of the amount due under the terms of the contract, and the city shall not be otherwise liable under the contract.