OAS has provided professional consulting engineering and commissioning services to a vast array of clients for the past 14 years. OAS’s work ethic is a reflection of the quality of work and the dedication of the staff to each and every project from start to finish. It is this commitment that has led many of OAS’s original clients to continue to work with our firm over the years. OAS is conveniently located in Sugar Grove, Illinois to serve the Chicagoland area and surrounding states. We have licensed professional engineers to serve every client market desired. Our engineering design experience includes Recreational, Educational, Commercial/Retail, Housing, Health Care, Municipal, County and State facilities. OAS is dedicated to providing innovation in design, ability to meet schedules, completeness and thoroughness of design, industry involvement, community involvement and customer satisfaction. It is a combination of these collections of services and the privilege to work with our distinguished clientele that keeps us at the head of the engineering community.