What are the top architectural firms in the world? And what does ‘best’ even mean in this context? The largest, the best-known, the one that’s turning over the most money?
The following list gives a brief introduction to the top 20 architectural firms in the world, taking into account these and other factors. Some are huge, some are relatively small.
There are companies that would be known even to those outside of the profession – step forward, Foster and Partners – and those that have dramatically shaped our cities without ever becoming a household name. But they have all had a profound influence on 21st century building.
Since this list is a guide, rather than a ranking, the firms are given in alphabetical order. And the inclusions and omissions are, of course, very much for up for debate!
The Top 20 Firms Architectural in the world
01 Aecom (USA)
Aecom has been named one of Fortune magazine’s most admired companies for six years in a row. It is a huge enterprise, offering services not only in architecture and design but in engineering, archaeology and risk management, among many others. Its revenue for the 2019 financial year was a cool $20.2 billion.
Although Aecom itself was established in 1990, many of its predecessor firms have histories of a century or more. Its notable projects include international airports (JFK, LAX, Sydney, Abu Dhabi, Hong Kong and more), Singapore’s Marina Bay, and the 2016 Summer Olympics in Rio.
The company is headquartered in Los Angeles, but its 87,000 staff are spread around the globe at offices in London, Abu Dhabi, Singapore, Hong Kong, Brisbane and Gurugram (northern India).
02 Aedas (Hong Kong)
Aedas was established in 2002 when three firms from Hong Kong, Australia and the UK merged. It now employs 1,400 staff in 12 offices (eight in Asia, two in the Middle East, one in Europe, one in the United States).
The company’s directors come from a wide range of cultural backgrounds, reflecting its belief that ‘a diverse world is a more interesting world’. As well as providing architectural services, it works in interior and urban design.
Aedas was honoured nine times at the 2020 International Design Awards, including for the Mongolia National History Museum and Zhengzhou Cultural District in China. And in spite of being a young company, it has already completed more than 100 projects.
03 BDP (UK)
With 950 staff, BDP is the second largest architectural firm in the UK. Its headquarters are in Manchester but it has eight more national offices, as well as global studios in Ireland, the Netherlands, the UAE, China, India, Singapore and Canada.
BDP was founded in 1961 by Prof Sir George Grenfell Baines, in whose name an award is given each year for an ‘inspiring place for people’. Grenfell Baines believed in humanising architecture although some of the firm’s projects, such as Preston Bus Station, have divided public opinion.
The company joined forces with Japanese engineer Nippon Koei in 2016, giving it an international reach. Recent projects have included Melbourne City Waterfront and the Liverpool One development, which was nominated for the Stirling Prize. BDP has also been commissioned for the high-profile renovation of the Palace of Westminster. In 2019, it announced its highest-ever turnover of £106.8 million.
04 DLR Group (USA)
DLR Group prioritises sustainable design; to this end, it was an early adopter of the Architecture 2030 Challenge and has signed the AIA 2030 Commitment and China Accord. Its commitment to sustainability can also be seen in its projects, such as the solar canopy at Miami’s AmericanAirlines Arena. It offers services connected to architecture, landscape architecture, interior design, preservation, energy, and several others.
DLR Group has won numerous awards for its sustainable Canyon View High School in Arizona, and has also recently reconstructed the much-loved, postmodern Portland Building.
The firm is headquartered in Omaha, Nebraska, with 25 additional American offices and outposts in Shanghai and Dubai. It has been running since 1966, with a reported annual turnover of $262 million and 1,200 staff in 2018.
05 DP Architects (Singapore)
DP Architects has been running since 1967 and now has 16 offices across Asia. Its footprint can be seen all over its native Singapore, for example in the master planning of the Orchard Road retail area and now-iconic Golden Mile Complex, but it was also responsible for the Dubai Mall and other international projects.
The company employs more than 1,100 staff. It is a multi-disciplinary design consultancy and part of the larger DP Group. The firm’s sustainable design ethos has been recognised by the Building and Construction Authority of Singapore, with 25 awards for green projects.
06 Foster and Partners (UK)
Foster and Partners is a global brand thanks to its lead ‘starchitect’, Norman Foster, who founded the company in 1967. It now has 1,600 employees and has won the Stirling Prize three times, the Aga Khan Award once, and other RIBA awards numerous times.
The firm has shaped modern London, having been responsible for the Gherkin (30 St Mary Axe), the new Wembley Stadium, Millennium Bridge, City Hall, and the glass roof in the British Museum’s Great Court. However, it has also worked on international projects such as the HSBC Building in Hong Kong, and the reconstruction of the Reichstag in Germany.
Foster and Partners’ revenue totalled £258 million in 2019. Ninety percent of this was made outside of the UK, which is perhaps not surprising given that 13 of its 14 offices are overseas (on every continent except Africa).
07 Gensler (USA)
Gensler is a large and well-known enterprise, operating in 48 cities worldwide and employing over 6,000 people. Its 2018 turnover was $1.2 billion.
It has been operating from its San Francisco headquarters since 1965, although two of its most notable buildings – Shanghai Tower and Incheon National Airport, South Korea – are not in the United States.
Gensler focuses on the urban environment, believing that ‘cities are the sum of their parts’ and claiming expertise in ‘airports, hotels, schools, offices, health and wellness centres, sports venues, entertainment destinations, and everything in between’. It has a number of civic engagement programmes focused on tackling homelessness, improving wellbeing, and training the next generation of architects.
08 HDR (USA)
HDR has a long history – it has existed since 1917 – and a sizeable global workforce of over 10,000 people. With headquarters in Omaha, it has set up more than 225 offices in the US, Europe, Asia and Australia. HDR is an employee-owned firm which turns over $2.2 billion per year.
It was the first architectural/engineering firm to join the US Green Building Council, back in 1994. It has continued this commitment and won awards for sustainability, as well as the Grand Conceptor Award for engineering.
HDR’s projects are many and various, often focusing on environmental intervention. They include the Hoover Dam Bypass on the Arizona-Nevada border, and the Life, Earth and Environmental Sciences Building at the University of Sydney.
09 Heerim Architects and Planners (South Korea)
Heerim is the leading architectural firm in South Korea, founded in 1970 and employing 1,200 staff. The company offers a wide range of services from lighting to construction management.
It has its headquarters in Seoul and an additional 13 offices in some rather unexpected locations, including Irbil (Iraq), Nur-Sultan (Kazakhstan) and Baku (Azerbaijan). In the latter city, it has won awards for its Olympic Stadium and Kempinski Hotel Crescent. Heerim is also currently acting as design consultant for the main football stadium to be used in the 2022 World Cup in Qatar.
10 HKS (USA)
HKS emphasises the importance of research in its practice, with a dedicated ‘lab’ within its Dallas HQ. The firm has been around since 1939, and completed high-profile projects such as 311 South Wacker Drive in Chicago, the Atlantic Paradise Island resort in the Bahamas, and a number of stadiums across the US. Over its history, it has worked on projects valued at almost $70 billion in total.
The company employs 1,400 people in 24 offices, mainly in the United States but also in Mexico City, London, Dubai, Toyko, Shanghai, Singapore and New Delhi. As well as architectural services, HKS offers services in interior design, structural engineering, ‘branded experiences’ and many more.
11 HOK (USA)
HOK (previously called Hellmuth, Obata + Kassabaum) began in St Louis in 1955 but now has 24 offices, with its most senior staff spread among them. It has a total workforce of around 1,700.
HOK is known for sustainable design and for its early adoption of CAD and BIM (it introduced a piece of drafting software called HOK Draw as early as 1983). It also runs mentorship programs for aspiring architects.
The firm’s major projects include the National Air and Space Museum in Washington, the Apple Research and Development Campus in Cupertino, Doha’s Hamad International Airport, and Keangnam Hanoi Landmark Tower – the tallest building in Vietnam.
12 IBI Group (Canada)
This Toronto-based firm has been operating since 1974 and is consistently ranked one of the world’s best architectural firms. It has 2,600 employees in 60 international offices, primarily in North America but also Europe, Asia and the Middle East.
IBI Group is oriented towards the intelligent integration of urban systems, ‘bridging the gap between design and technology’. It has primarily worked on placemaking, transportation, education and healthcare buildings, as well as residential and commercial premises.
Examples of IBI’s work include Boston’s Chinatown Park, the Queen Elizabeth University and Royal Hospital for Children in Glasgow, and the Saudi Arabia Integrated Transportation Urban Plan.
13 Nihon Sekkei (Japan)
Nihon Sekkei (not to be confused with Nikken Sekkai, below!) began in Sapporo and Nagoya in 1967. It now has additional offices in Shanghai and Hanoi, employs almost 1,000 staff in total, and has an estimated annual turnover of $180 million.
The firm believes in the ‘co-creation [with clients and the public] of future values’ that can be incorporated into the built environment. It describes this philosophy as ‘Think ++’.
The influence of Nihon Sekkai can be seen all over urban Japan, particularly in its skyscrapers. Some of the company’s most famous buildings are Itoman City Hall in Okinawa and Mitsui Memorial Hospital in Toyko, as well as overseas projects such as Shanghai Pudong Library.
14 Nikken Sekkei (Japan)
Nikken Sekkei (not to be confused with Nihon Sekkei, above) is the leading architectural firm in Japan and the second largest in the world, having completed 25,000 projects since its inception in 1900. It has expanded from Tokyo into 16 cities worldwide including Moscow, Riyadh and, most recently, Bangkok.
It has a workforce of 2,685 and offers a full range of services including architectural design, interior design, urban planning, consulting and sustainability, amongst others.
It has worked on some of the most prestigious architecture in Japan, including Tokyo Skytree, Grand Front Osaka, and Queen’s Square Yokohama. Overseas, Nikken Sekkei has been responsible for Cairo Opera House, Guangzhou Library and more.
15 Perkins & Will (USA)
Chicago-based Perkins & Will has been creating ‘places than honor humanity’ since 1935. It employs 2,600 people, and has been a subsidiary of the Lebanese firm Dar Al-Handasah since the 80s. It has 25 offices in seven countries.
The company has the highest number of LEED (Leaders in Energy and Environmental Design)-accredited staff in the US and a well-known Diversity, Inclusion and Engagement programme. Perkins & Will architects designed Washington’s National Museum of African American History and Culture and Atlanta’s National Center for Civil and Human Rights, as well as redesigning the Historic Emancipation Park in Houston.
16 Perkins Eastman (USA)
Perkins Eastman has 1,000 employees in 17 offices, with headquarters in New York. It has a ‘philosophy of convergence, whereby a diversity of practices, disciplines, and perspectives come together to yield practical and holistic solutions’. The firm was founded in 1981 and is still led by founders Bradford Perkins and Mary-Jean Eastman.
It was nominated for, or won, 17 major architectural awards in 2018 and again in 2019. Projects which were recognised include the mixed-use District Wharf in Washington, the School of Nursing and Science at Rutgers University in New Jersey, and renovation work on New York’s Tenement Museum.
The firm has eight American offices and outposts in Canada, Ecuador, the UAE, China and India.
17 P&T Group (Hong Kong)
The oldest firm on the list, P&T Group (formerly Palmer and Turner Hong Kong) has been operating since 1868 and completed over 5,000 projects. Today, P&T employs 1,600 staff in 14 offices.
It has left its mark on the East and Southeast Asian regions with projects such as the Pedder Building, Exchange Square and the Science Museum in Hong Kong; MacDonald House in Singapore; and the HSBC Building and Customs House in Shanghai. In 2019, the company received 17 awards for buildings in Hong Kong and Thailand.
It is also known for its P&T Travel Scholarship, which is awarded each year to several architecture students from Hong Kong, allowing them to pursue further studies overseas.
18 Stantec (Canada)
With 22,000 employees, Stantec is one of the largest architectural firms in the world, turning over $4 billion each year. It has its headquarters in Edmonton, Alberta, supported by 410 offices across North America and internationally.
Stantec’s guiding philosophy is to ‘design with community in mind’. The company has internal Inclusion and Diversity Councils, and is working towards Progressive Aboriginal Relations certification.
Stantec offers a diverse range of services that extend to geomatics, water engineering, and oil and gas EPCM. Some of its recent projects include Distrito Sante Fe in Mexico City, Gull Bay First Nations Diesel Offset Microgrid in Ontario, and the Yale Science Building in New Jersey.
19 Sweco (Sweden)
Sweco is the leading architectural and engineering firm in Europe, with headquarters in Stockholm. It has offices in 13 countries and works on an average of 70 projects each year. Its workforce numbers 22,000, while its annual revenue is €1.9 billion euros.
The company is geared towards sustainable design and resilience-building that take into account three contemporary trends: urbanisation, digitalisation and climate change. Its major projects, since its founding in 1997, have included the Kuwait Towers, Bloomberg European Headquarters in London, and the Øresund Bridge linking Sweden and Denmark.
20 Woods Bagot (Australia)
Having operated from Adelaide since 1869, Woods Bagot is the second oldest firm on the list. It has worked in a variety of styles during its long history, although its more recent work is inspired by the natural world and by the cultural context of the buildings. It describes itself as a ‘People Architecture’ company.
Woods Bagot currently employs 850 staff in 16 international studios. It offers services under three umbrellas: Urban Systems, Super Space and Brand Studio. Notably, the firm has designed the National War Memorial in Adelaide, the Melbourne Convention and Exhibition Centre, and the Qatar Science and Technology Park.
To sum up…
The companies on this list are a diverse bunch, spanning three continents and ranging from 850 to 87,000 employees. The oldest is more than 150 years old, while the newest has existed for less than two decades.
There is no one formula that makes a successful architectural firm, but what they seem to have in common is responding to changing times and needs. Getting a position inside any one of them would be challenging, rewarding – and very impressive!