During his tenure with Oltmans, the company rose to perennially rank among the top 20 commercial and industrial general contractors based in Los Angeles County, and regularly earned national ranking among the nation's top 200 contractors, designations it retains to this day. J.O. Oltmans II, chairman and CEO of Oltmans Construction Co., commented on the role that Holmes played in the company's growth.

"Along with my grandfather, J.O. Oltmans, founder of Oltmans Construction Co., my father, 'Bud' Oltmans, a former chairman, and Dennis Roy Sr., Bob Holmes was instrumental in earning widespread respect for our company and increasing the competency of our services for over four decades," J.O. Oltmans said.

In addition to his executive leadership, Holmes played a leading role in professional and civic affairs. He was a past president of the California Building Industry Association and was elected a lifetime delegate in 1971. He was also a former president of the Los Angeles-based Building Constructors Association of California (now Building Industry Association).