Design consultancies headquartered in the US and UK continue to account for a significant share of activity of major projects worldwide, according to GlobalData’s 2025 Global 500 Design Companies ranking, which is based on the number of live projects valued at $25m or more.

Just over half of the companies in the Global 500 list are headquartered in either the US or the UK. Together, these firms are involved in 48% of all live mega-projects that feature the Global 500 companies, underlining the continued concentration of corporate headquarters in a small number of mature markets.

Canada and Australia are the next most prominent headquarters locations, with 68 and 47 companies respectively included in the global list.

Diversification drive

Despite the concentration of headquarters, the largest design firms maintain widely spread portfolios across multiple regions.

GlobalData’s Regional Diversification Index – which measures the spread of projects across eight major regions, with a score of 0 indicating all projects in one region and 1 indicating an even spread across all regions – ranks US-based Aecom as the most geographically diversified company among the top 20 firms for 2024.

The highest-ranked company outside the four leading headquarters markets is Netherlands-based Arcadis, which is ranked third on the diversification measure. Lebanon-headquartered Sidara (Dar Group) remains in the top 10, ranking fourth. Sidara is the parent of US-based firms including architects Perkins&Will and engineering consultants TY Lin International Group, which ranks sixth.

Sidara agreed in September 2025 to acquire UK-based Wood Group a global consulting and engineering firm focused on energy and materials. The transition is not yet complete, but is expected to be finalised in the first half of 2026.

Stable rankings

The top 10 design companies largely retained their positions between 2024 and 2025, with only three changes in ranking and no new entrants.

Tetra Tech rose from 10th place in 2024 to seventh in 2025. Kimley-Horn & Associates slipped from seventh to eighth, while Gensler fell from eighth to 10th. Jacobs maintained ninth place.

The Global 500 list comprises 283 companies classified primarily as architects and 217 as engineering consultants or other consultants. The ranking excludes firms that primarily provide construction contracting services.

Consultants dominate the highest positions, with Gensler the leading architect in 10th place, ahead of Japan’s Integrated Design & Engineering Holdings (formerly Nippon Koei) in 11th.

Canada-based WSP Global retained the top ranking by number of live projects in 2025, with the company continuing to expand through acquisitions. In June 2025, WSP announced an agreement to acquire UK-based Lexica, which specialises in healthcare and life sciences engineering and consulting. In October 2025, it further broadened its engineering services platform with the acquisition of Ricardo plc.

Stantec remained second, supported by acquisitions aimed at expanding its buildings and water businesses. These included the purchase of US-based architecture firm Page and Ireland’s Ryan Hanley in April 2025, followed by New Zealand’s Cosgroves in June 2025.

GlobalData’s latest findings suggest that while the sector’s corporate base remains concentrated, leading design firms are increasingly operating with geographically diversified portfolios and using acquisitions to strengthen sector expertise and broaden service lines.