Fosters back as UK’s biggest architect and breaks into top 20 of world’s largest practices

Foster & Partners has leapfrogged past large global practices including HOK, Atkins Réalis and HKS to become the 13^th biggest architectural practice in the world according to the WA100, BD’s international survey of the world’s 100 largest firms.

The London headquartered firm, which in 2025 was usurped by BDP as the UK’s biggest practice, increased its headcount from 515 in 2025 to 725, a 41% jump. 

It also increased turnover by 55% to the £800m-£899m range. According to accounts filed last April, profit jumped from £2m in 2024 to £74m.

Stuart Latham, managing partner at Fosters, said the increase in headcount was due to the practice winning a series of large design competitions in the Middle East with demand in Saudi Arabia particularly strong.

The practice had the highest global turnover of £444m for the Middle East, a doubling over 2025’s figure. Fosters also pushed Gensler, which took the top spot as the world’s largest architect for the tenth year running, into second place for turnover from architectural services.

> Also read: WA100 2026: The big list

Architects were the most positive about the Middle East with 85% predicting growth or strong growth in the region this year.

They were also positive about Central Asia including India with 81% predicting growth. Architects were the most pessimistic about prospects for growth in Western Europe with just 35% expecting growth and 48% predicting stagnation. Globally, 65% of architects said they expected growth compared to last year’s 59%, the most optimistic the profession has been since 2021’s covid rebound.

The UK’s second largest firm, BDP dropped two places to 23^rd place, the spot Fosters occupied last time, with a drop of 61 architects to 493 for 2026. Grimshaw appeared in the rankings for the first time this year in 64^th place with 209 architects.

Overall, the top 10 firms, which are dominated by US firms including Gensler, HDR, DLR and Perkins & Will increased their headcount by 35% compared to 8.2% for all 100 firms in the rankings. This continues a trend of the largest firms expanding faster than smaller practices.

Architects are positive about recruitment prospects for the year ahead with just 2% saying they didn’t expect to recruit any staff this year. In all, 40% of firms said they expected to recruit 11-30 architects with 20% saying they expected to recruit over 50 architects.

Many practices report that they are investing in artificial intelligence with some employing dedicated teams to drive the technology into their businesses. Firms are using generative design tools to test multiple design options in minutes and to produce more realistic visualisations to help clients experience spaces, giving them more confidence in the finished product. None of the firms in the survey said AI would replace architects but instead would automate dull, repetitive tasks giving them more time to focus on using their experience to produce better designs.