From No. 74 to No. 9: How GSI Environmental Built a Top-10 Firm Without Abandoning Its Model
By Liisa Andreassen Two years ago, GSI Environmental made its first appearance in the Hot Firm rankings at No. 74. In 2025 it moved to No. 25. This year, as the Houston-based firm marks its 40th anniversary, it landed at No. 9 on the SNZweig Hot Firm list. Rapid climbs like that tend to invite a hunt for a single cause, such as a hot market, an acquisition or a new service line. According to GSI President Travis McGuire, the real answer is less dramatic and more useful to other AEC firms. Investments That Paid Off McGuire points to timing. “Our growth is attributed to the cumulative effect of several strategic investments reaching maturity over the past several years,” he says. Those investments were both geographic and technical. GSI added offices in Denver, Montana and Atlanta, and built capabilities in aquatic science, mining, sustainability and climate, PFAS and emerging contaminants and services for fast-growing markets suc...