§ 5-323. Agreements exempting building service or maintenance contractors from liability for negligence void and unenforceable. Every covenant, agreement or understanding in or in connection with or collateral to any contract or agreement affecting real property made or entered into, whereby or whereunder a contractor exempts himself from liability for injuries to person or property caused by or resulting from the negligence of such contractor, his agent, servants or employees, as a result of work performed or services rendered in connection with the construction, maintenance and repair of real property or its appurtenances, shall be deemed to be void as against public policy and wholly unenforceable.