20. Architects, mechanical engineers, electrical engineers, civil and structural engineers, architectural, mechanical and electrical project coordinators are authorized to sign(1) contracts for professional services where the amount is less than $10,000;
(2) contracts for services other than professional services where the amount is less than $50,000; and
(3) orders for changes and riders to contracts for services other than professional services where the amount is less than $5,000, and to contracts for professional services where the amount is less than $1,000.