SDL began in 1966 in Nashville, Tennessee.  Dr. Stan Lindsey (1938-2014) was working for a steel fabricator, Volunteer Structures, and working towards his Ph.D. at Vanderbilt University. Volunteer Structures wanted a separate company solely for structural engineering and Dr. Lindsey agreed to lead that initiative. The firm’s first project was the design of a Student Union building at Tennessee Agricultural and Industrial State University, now Tennessee State University.

At that time, all engineering calculations and drafting were done by hand. The use of computers in design was very new, but Dr. Lindsey saw the value of using computers in design as a great opportunity to create efficient design calculations. With the firm’s connection to Vanderbilt University, SDL was able to have access to their computers. A graduate student named Jack Horner, who is still with the company as a Vice President, joined the firm and brought his thesis work developing frame analysis.

Due to its work at the forefront of the computing era and strong client relations, the company grew through the 1970’s. In 1982 SDL acquired an in-house computer system. This came with the influence of the new development of computer aided drafting and a push by Hospital Corporation of America to get their architects and engineers started on this new technology.

In the late 1980’s Atlanta was a quickly growing market with several architect clients based there. Mike Regen, a field engineer at the time and now a Vice President, moved to Atlanta in 1989 to perform construction administration on various Atlanta projects establishing SDL’s Atlanta office. In 1990 Dr. Lindsey and eight additional employees from the Nashville office moved to Atlanta to officially open the office.

Over the next 20 years both offices experienced growth and designed signature projects throughout the southeast and nation with numerous repeat clients. The company was recognized with awards from AISC and ACI for innovative and creative designs.

In 2002, Dr. Lindsey sold his majority stake in the company to four long-time employees and a transition of the company began in terms of personnel but not in philosophy. Dr. Lindsey moved to Savannah and became a professor in the School of Civil and Environmental Engineering at the Georgia Institute of Technology teaching students in the practical art of design. Dr. Lindsey passed away suddenly in 2014 on his horse farm, leaving behind his wife, children, and a company indebted to his vision.  The company continues to thrive under the leadership of four majority shareholders and maintain the essence of Dr. Lindsey’s founding ideals of innovation and practicality.