Things an AEC Company Or Owner Should Know When Hiring An Estimating Consultant Firm To Do Work For Their Business By Edward Walsh, Executive Director – CERT The Consulting Estimators Round Table [www.CERT-USA.org] has developed some recommended guidelines for any AEC firm, building owner or developer thinking about hiring the services of a CE firm. The CERT is a national non-for profit association which promotes ethics, validation, education and fellowship of consulting estimator firms based exclusively in the United States.