The Top 30 AEC Firms

Updated Oct 4, 2023
Man in underground train tunnel - The top AEC firms

CAD skills open up doors to a vast range of careers across some of the most exciting industries to work for. This, then, leaves you with an important question: where to apply? If you’re looking for a company with a big vision and the chance for real career progression, a good place is to start at one of the top 30 AEC firms.

In this article, we’ll provide a rundown of the top firms in architectureengineering and construction. With major projects ongoing at any time, they offer an exciting working environment for ambitious engineers and designers. Let’s check out who made the list!


We’ll break the top thirty firms in this article down to the three components of AEC. To begin, we’ll look at the top ten architecture firms in the world, and explore some of their best-known projects.

1. Gensler

Headquarters San Francisco, CA, United States
Architectural revenue (2018) $1.197 billion
Total employees 6,000+

Where better to start than with the company that, according to Architectural Review, had the highest architectural revenue of any firm in 2018? Yes, it’s Gensler who top that list—and they’re becoming quite the fixture there, having spent seven years at the summit. This mega-firm has plenty of marquee projects to its name, including JetBlue T5 at JFK International Airport, as well as the Shanghai Tower. One of their biggest projects unveiled to the public this year was Terminal 2 of Incheon International Airport, whose opening coincided with the 2018 Winter Olympics held in nearby Pyeongchang.

2. Perkins+Will

Chase Tower Chicago

One of Perkins+Will’s best known projects is Chase Tower in Chicago. Image source: Wikimedia Commons

Headquarters Chicago, IL, United States
Architectural revenue (2018) $551.4 million
Total employees 2,200

Perkins+Will has a long history, having been founded in 1935 in Chicago. Since it first opened its doors, though, the firm (founded, appropriately, by Lawrence Perkins and Philip Will) has helped to transform the Midwestern city it still calls home. One of its key works is the Chase Tower, which has stood as one of Chicago’s tallest buildings since its opening in 1969. Perkins+Will wouldn’t be on this list if they’d stood still since then, though, and more recent projects have included the New York City Police Academy and Shanghai Natural History Museum.


Headquarters Los Angeles, CA, United States
Architectural revenue (2018) $533.80 million
Total employees 87,000

Next on our list is the first company that isn’t a strict architecture-only firm. In fact, AECOM’s architectural revenue accounts for a slender 7% of the total business. Even so, the company have found themselves outcompeting almost every architecture firm on the planet. Not bad going. Major ongoing projects include the Al Wakrah Stadium in Qatar. A collaborative project with Zaha Hadid Architects, it will serve as one of the host stadia for the 2022 FIFA World Cup.

4. Jacobs

Jacobs logo on yellow

Headquarters Dallas, TX, United States
Architectural revenue (2018) $431.32 million
Total employees 77,000

Next up is another combined architecture, engineering and construction group: Jacobs. Unlike AECOM, which, with its foundation date of 1990, is a relative spring chicken, Jacobs has been in the game since 1947. Astonishingly, the $431 million the company made in architectural revenue represents only around 4% of the overall business, which, as a whole, has revenue approaching $10 billion. Fittingly for such a colossal company, there’s no single ‘Jacobs style’, with the company instead striving for “architectural design excellence” that fits each client’s identity. Interiors are a key part of Jacobs’ architecture business, as well as regional projects such as the Northern Ballet Headquarters in Leeds, England, in the picture above.

5. HKS

Headquarters Dallas, TX, United States
Architectural revenue (2018) $408.60 million
Total employees 1,000+

We’re staying in Dallas for the fifth entry on our list, but this time, we’re back to a pure architecture firm. HKS are known for a number of major projects—everything is bigger in Texas, after all. Plenty of those projects are, indeed, in HKS’ home state, including the AT&T Stadium in Arlington and the American Airlines Center in Dallas. The firm haven’t shied away from setting their sights further afield, though, and they’ve worked on major overseas projects such as the Venetian Macao, a combined resort-hotel housing the world’s largest casino.

6. HOK

Headquarters St. Louis, MO, United States
Architectural revenue (2018) $407.34 million
Total employees 1,700+

Around since 1955, HOK began life with just 26 employees, together with its three founders: Hellmuth, Obata and Kassabaum. They’ve come a long way from the small architecture firm whose early jobs were mostly St. Louis schools. Over the years, their major projects have included the Kellogg World Headquarters in Battle Creek, MI; King Khalid International Airport in Riyadh, Saudi Arabia; and the Mercedes-Benz Stadium, home to the Atlanta Falcons. Under construction at the moment is the company’s Spire London project, set to become the tallest residential tower in western Europe.

7. HDR

Headquarters Omaha, NE, United States
Architectural revenue (2018) $401.80 million
Total employees 10,000

Next on our list is another firm with a Midwestern base: HDR, headquartered in Omaha, Nebraska. Only around a fifth of the company’s revenue comes from its architectural activities, but there’s still plenty worth talking about. Perhaps the company’s most notable project is the Mike O’Callaghan–Pat Tillman Memorial Bridge—the bridge spanning the Hoover Dam, and connecting the states of Arizona and Nevada. Another project in the Southwest is the Walter Cronkite School of Journalism in Phoenix, AZ, while the firm also designed the Baxter Arena in its hometown of Omaha.

8. IBI Group

IBI Group logo


Headquarters Toronto, ON, Canada
Architectural revenue (2018) $307.10 million
Total employees 2,400

The first non-U.S. firm to make the list, IBI Group is a Canadian firm that opened for business in 1974. They’re notable for their large number of acquisitions over the years, acquiring offices across Canada, the U.S. and the U.K. Key projects include 41 Cooper Square, which houses the Albert Nerken School of Engineering in Manhattan, NY. Across the pond, the firm was also responsible for the Queen Elizabeth University Hospital in Glasgow, Scotland, and masterminded the travel demand management program for the London 2012 Olympics.

9. Stantec

Manchester Institute of Biotechnology

Image source: Wikimedia Commons

Headquarters Edmonton, AB, Canada
Architectural revenue (2018) $304.53 million
Total employees 22,000+

As the first Canadian to ever earn a PhD in environmental engineering, Dr. Don Stanley already had one claim to fame under his belt. He could easily have rested on his laurels from that point, satisfied that he’d already made history. Instead, he went on to found one of the world’s largest AEC firms: Stantec. Though its engineering work makes up the bulk of its revenue, Stantec nevertheless makes it onto our list of the biggest architectural firms thanks to projects such as the Molson Coors HQ in Denver, CO; China’s Renaissance Shanghai Putuo Hotel; and the Manchester Institute of Biotechnology in England.

10. Skidmore, Owings & Merrill

Headquarters Chicago, IL, United States
Architectural revenue (2018) $249.00 million
Total employees 1,700+

Sure, Skidmore, Owings & Merrill (or, for short, SOM) may ‘only’ have made it to tenth on this list. But we doubt they’re feeling too beat up about it. After all, we’re talking about an architectural firm that built nothing less than the world’s tallest building, the Burj Khalifa—and has so many other major works going on that they’ve tucked it a loooooooong way down on their projects page. (Sure, it was over a decade ago that the Burj opened—but if it were us, we’d definitely still be crowing about it.) Bravo, SOM.


Defining who to include in a list of the top engineering firms can be tricky. After all, there are civil, mechanical, electrical and chemical engineering firms to take into account, alongside a wide range of other branches and sub-branches of the field. Then there’s the issue of firms which stray onto the territory of architecture or construction. Nonetheless, we’ve whittled the near-interminable list down to come up with ten of the top engineering firms.

1. WSP Global

WSP Global logo inverted

Headquarters Montreal, QC, Canada
Revenue (2016) $4.75 billion
Total employees 43,600

While architects tend to take much of the credit for our most iconic buildings, we forget all too often the engineering work that goes into creating them. After all, if we did give engineers their proper dues, WSP Global would surely be a household name. The company have had a hand in everything from The Shard in London to the Petronas Towers in Kuala Lumpur. Meanwhile, a huge chunk of New York’s skyline has WSP’s fingerprints all over it, including One World Trade Center, the New York Times Building, and Trump Tower

2. SNC-Lavalin

William R Bennett Bridge

The William R. Bennett Bridge in Kelowna, BC. Image source: Wikimedia Commons

Headquarters Montreal, QC, Canada
Revenue (2015) $7.11 billion
Total employees 50,000

We stay not only in the same country and province, but in the same city for our second pick: SNC-Lavalin. While it may share a hometown with WSP Global, SNC-Lavalin has a very different focus, with specializations in oil and gas, mining, power stations and energy distribution. They’re also involved in major infrastructure projects in Canada, including the William R. Bennett Bridge in British Columbia and the Confederation Line in Ottawa, Quebec.

3. Arcadis

Millau Viaduct

Image source: Richard Leeming

Headquarters Amsterdam, Netherlands
Revenue (2016) $3.76 billion
Total employees 27,000

The first European-based firm anywhere on our list is Arcadis, a Dutch company with a global reach. Across the world, they’ve been involved in some groundbreaking work, including providing drinking water to one and a half million people in São Paulo, Brazil, and constructing the Sainsbury Wellcome Centre, home to some of the world’s leading research in neuroscience. Even if you haven’t heard of these cutting-edge projects, you’ll surely be familiar with the stunning Millau Viaduct above. Spanning the Tarn Valley in southern France, this is the world’s tallest bridge, 23 meters higher than the Eiffel Tower.

4. Fluor Corporation

Planet Hollywood Las Vegas

Planet Hollywood Las Vegas was built by Fluor in 2001. Image source: Kris Ziel

Headquarters Irving, TX, United States
Revenue (2017) $19.52 billion
Total employees 56,706

With a history spanning back over a century, Fluor Corporation is one of the oldest firms featured on our list. In its earliest days, Fluor focused on a range of infrastructure and energy projects in California. From the thirties, however, the company began turning its attention out of state, before amassing international projects such as Chile’s Escondida copper mine and the King Abdulaziz Air Base in Saudi Arabia. In more recent years, the company has been involved in recovery operations following Hurricane Katrina, as well as rebuilding after the Iraq War.

5. Tetra Tech

Headquarters Pasadena, CA, United States
Revenue (2018) $2.96 billion
Total employees 17,000+

It should come as no surprise in this point in the list to learn that Tetra Tech is a company with fingers in many different pies. Nonetheless, the diversity of the firm’s projects is still staggering. Housing in the U.S. Embassy in Baghdad, Iraq? Check. Improvements at Iqaluit Airport in Nunavut, Canada? That, too. A geothermal project in Kenya? You bet. Tetra Tech is best known, however, for its services in the water sector. In fact, Engineering News-Record has listed Tetra Tech as the number one company in water for fifteen years.

6. KBR

South Arne Phase III

Image source: KBR

Headquarters Houston, TX, United States
Revenue (2017) $4.17 billion
Total employees 20,000

When it comes to industry sectors, KBR is, perhaps, a little less expansive than some of the fellow engineering firms that made this list. Take a look at the company’s major projects, and certain key themes will crop up time and again: refineries, LNG and ammonia plants, and oil platforms. Where the company stands out, however, is in its geographical breadth, with operations across six continents, spanning from the Northwest Territories to Tierra del Fuego. Among the company’s non-energy related projects are the U.S. Embassy in Macedonia and the Devonport Royal Dockyard in England.

7. WorleyParsons

Gas pipeline on rural land

Headquarters North Sydney, NSW, Australia
Revenue (2018) $3.12 billion
Total employees 26,200

Formed in 1971 in Sydney, WorleyParsons is the only Australian company in our list of the top 30 AEC firms. Nonetheless, they certainly do a good job of representing the Southern Hemisphere as one of the world’s largest engineering and consultancy firms in the energy sector. In 2018, they celebrated the opening of the Trans-Anatolian Natural Gas Pipeline, the largest diameter pipeline ever built. They also have an advisory role on the world’s largest solar power project in Dubai, as well as an engineering contract for Kenya’s Kipeto Wind Power Project.

8. Dar Group

Headquarters Dubai, United Arab Emirates
Revenue (2017) $2.47 billion
Total employees 18,600

Ranked as the #1 firm in sectors as diverse as Healthcare, Airports and Education, it’s certainly an exciting period for the Dar Group. The UAE-based company’s projects focus on infrastructure, architecture, project management and energy, which it sees as key to sustainable growth. The group has a global footprint, with projects ranging from the Princess Nora Bint Abdulrahman University in Saudi Arabia to the Bank of Canada.

9. Mott MacDonald

Mott Macdonald logo

Headquarters Croydon, United Kingdom
Revenue (2016) $1.76 billion
Total employees 16,000

The history of Mott MacDonald stretches back to 1902, with founder Basil Mott having worked on the original London Underground. For the first century of its existence, it remained largely a U.K.-focused firm. In 2008, the company’s international takings outweighed its British earnings for the first time. Today, its overseas projects include the Marina Coastal Expressway in Singapore, Highway 1, and a nationwide water program in Tajikistan. Mott MacDonald hasn’t forgotten its roots completely, though, having been involved with Heathrow Terminal 5, as well as London’s new Crossrail line.

10. Arup

Headquarters London, United Kingdom
Revenue (2018) $1.57 billion
Total employees 12,806

We finish up our engineering section with another British firm: Arup. Specializing in the built environment, Arup have acted as structural engineers on many of the most recognizable buildings of our time. Their impact is notable in their home country, the U.K., where their projects have included the HSBC Tower30 St Mary Axe (the Gherkin), the London Eye, the Angel of the North and the Lloyd’s Building. Their international projects, meanwhile, have been no less prominent, including the CMG Headquarters and Bird’s Nest in Beijing; the HSBC Main Building in Hong Kong; and the Sydney Opera House.


At one point, it may have been forgivable to think of the work of architects and engineers as being more conceptual, while the construction sector got on with putting the theory into action. The dawn of BIM, however, has brought the disciplines closer together than ever before.

With this in mind, we move onto our final group of companies: construction firms. As you may guess, these firms combine construction with engineering and, in some cases, architecture. Let’s take a look at these firms and the projects they’re behind.

1. ACS

Torre Glories

Image source: Wikimedia Commons

Headquarters Madrid, Spain
Revenue (2016) $38.72 billion
Total employees 210,345

Spain’s ACS Group (Actividades de Construcción y Servicios) has established itself as one of the world’s major players in both construction and civil engineering. Under the vast ACS umbrella is Dragados, which has carried out construction work on the iconic Torre Glòries skyscraper in Barcelona, as well as on Madrid’s Torre de Cristal and Torre Cepsa

2. Hochtief

hochtief logo

Headquarters Essen, Germany
Revenue (2017) $25.75 billion
Total employees 53,890

Break down the word ‘Hochtief’ into two parts, and you’ll get the German words for ‘high’ and ‘deep’. Fittingly, its major projects have reached both to the stars and deep into the belly of the earth. Take the Zollverein complex, for example: an industrial site so important it’s listed as a UNESCO World Heritage Site. More recently, the company have been behind the construction of several skyscrapers in Germany’s financial capital, Frankfurt, as well as Ukraine’s Dnipro Arena.

3. China Communications Construction

Headquarters Beijing, China
Revenue (2017) $70 billion
Total employees 118,000

We now come to the first (but by no means the last) of the Chinese firms to make our list. China Communications Construction is a slightly misleading name: infrastructure is the name of the game when it comes to this firm. 2018 saw the completion of the long-awaited Hong Kong–Zhuhai–Macau Bridge, connecting China’s two Special Administrative Regions to the mainland. Away from China, the company is also involved in notable projects in countries such as Jamaica, Malaysia, Senegal and Mozambique.

4. Vinci

Vasco da Gama Bridge

Vasco da Gama Bridge in Lisbon, Portugal. Image source: F Mira

Headquarters Reuil-Malmaison, France
Revenue (2017) $45.79 billion
Total employees 194,428

One of two French companies to make the list, Vinci is one of Europe’s largest construction firms. Vinci’s work is diverse, including the reconstruction of Whiston Hospital near to Liverpool, England; the Atlantic Bridge spanning the Panama Canal; and the Basilica of Our Lady of Peace in Yamoussoukro, Côte d’Ivoire. They also constructed the Vasco de Gama Bridge in Lisbon, Portugal, as well as operating airports in France, Portugal, the U.S. and beyond.

5. Strabag

Headquarters Vienna, Austria
Revenue (2017) $15.38 billion
Total employees 71,839

Strabag is Austria’s largest construction firm, employing over 70,000 people in projects across Europe and around the world. Indeed, few of its major projects are in its home country; instead, they include works such as the Alte Weser lighthouse off the German coast in the North Sea; Terminal 2 of Sofia Airport in Bulgaria; and Basra International Airport in Iraq. Infrastructure works have included Limerick Tunnel in Ireland and Vrmac Tunnel in Montenegro.

6. TechnipFMC

Headquarters London, United Kingdom
Revenue (2017) $13 billion
Total employees 37,000

A far cry from many of the broad-reaching construction firms featured here, TechnipFMC focuses on oil and gas. The company itself is one of the newest on the list, having arisen from a merger between France’s Technip and US firm FMC in 2017. The merged firm, therefore, carries considerable clout, and has been involved in projects in Russia, the UAE, Australia, India and Norway, amongst many more locations worldwide.

7. Bouygues

Image source: Wikipedia

Headquarters Paris, France
Revenue (2017) $37.44 billion
Total employees 115,530

Its name may be a mouthful for non-Francophones (‘bweeg’ is a decent enough approximation for English-speakers), but Bouygues is still a name on everyone’s lips. In France, it’s been a driving force behind some of the country’s major construction projects, including the Musée d’Orsay and Stade de France. They also formed part of the consortium behind the Channel Tunnel. More recent flagships have included the Paris Law Courts and Bordeaux Métropole Aréna.

8. China State Construction Engineering Corporation

Headquarters Beijing, China
Revenue (2017) $156.07 billion
Total employees 270,467

With a name emphasizing its nationality, you might expect CSCEC to have a Sino-centric focus. It’s certainly true that some of the company’s most well-known buildings are in China, such as the Shanghai World Financial Center and Beijing National Aquatics Center. However, CSCEC has spread its wings, with a particularly large number of projects in the MENA region, including the Doha Tower and Great Mosque of Algiers.

9. Skanska

Øresund Bridge

The Øresund Bridge linking Denmark and Sweden. Image source: Nick-D

Headquarters Stockholm, Sweden
Revenue (2016) $15.98 billion
Total employees 42,903

Sweden’s Skanska has been around for well over a century, having its origins in a cement company founded in 1887 in Malmö. Since then, it’s made the move from southern Sweden to the capital, and has undergone dramatic international expansion. Skanska’s major projects have included the MetLife Stadium, as well as renovation work on the United Nations headquarters. Close to the company’s traditional home, they were part of the group that constructed the Øresund Bridge, which links Malmö to Copenhagen, Denmark.

10. Power Construction Corporation of China

Headquarters Beijing, China
Revenue (2017) $40.05 billion
Total employees 131,000

We finish up with one of the newest companies to make our list: Power Construction Corporation of China (or POWERCHINA for short), whose history spans back only to 2011. With the company’s name, it shouldn’t come as a shock to learn that many of the company’s major projects are in the energy sector, particularly hydropower, while water conservancy is also high on the agenda. Recently, the company has undertaken hydroelectric projects in Laos, Cambodia, Ecuador and Sudan.

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