§ 20. Work done by special order. The commissioner of general services shall determine when minor work of construction, reconstruction, alteration or repair of any state building may be done by special order. Special orders for such work shall be short-form contracts approved by the attorney general and by the comptroller. No work shall be done by special order in an amount in excess of one hundred thousand dollars and a bond shall not be required for special orders. No work shall be done by special order unless the commissioner has presented to the comptroller evidence that he has made a diligent effort to obtain competition sufficient to protect the interests of the state prior to selecting the contractor to perform the work. Notwithstanding the provisions of subdivision two of section eight of this chapter, work done by special order under this section may be advertised solely through the regular public notification service of the office of general services. At least five days shall elapse between the first publication of such public notice and the date so specified for the public opening of bids. All payments on special orders shall be made on the certificate of the commissioner of general services and audited and approved by the state comptroller. All special orders shall contain a clause that the special order shall only be deemed executory to the extent of the moneys available and no liability shall be incurred by the state beyond the moneys available for the purpose.