Del. Code tit. 31, § 4124

No officer or employee who has an official duty in connection with the administration and enforcement of this chapter shall be financially interested in the furnishing of labor, materials or appliances for the construction, alteration or maintenance of a building or in making the plans or specifications therefor, unless that person is the owner of such building. No such officer or employee shall engage in any activity which is inconsistent with the public interest and the officer’s official duties.