We support the development of engineering excellence

After working abroad for six years, 29-year-old engineer Christen Ostenfeld returned to Copenhagen in 1930. Full of creative energy, he established his business in a small apartment in Copenhagen's working-class neighbourhood, Vesterbro. Ostenfeld established his company with the philosophy of bringing academic knowledge into practical engineering that is measured on international standards.

In 1931, Ostenfeld was hired to reconstruct the worn-down Scala Theatre in Copenhagen. With a short deadline, he had to work fast. He introduced prefabricated steel elements that made scaffolding redundant during construction. The new National Scala opened its doors in less than a year. During the 1930s, COWI's speciality was construction with prefabricated elements and long-span roofs, designing K.B. Hallen in Copenhagen and a brewery hall for Tuborg.

After only five years in business, Ostenfeld landed his first international assignment: the design of the Danish pavilion for the 1935 World’s Fair in Brussels. All the pavilion elements were made of prefabricated Danish pinewood and then shipped to Antwerp and transported onward to Brussels by truck where it was assembled and painted on site.

Ostenfeld had, from the beginning, designed a few minor bridges across Denmark. When the new Aggersund Bridge across Limfjorden in northern Jutland was planned, Ostenfeld persuaded the Danish state to put the works out to a private tender for the very first time and also won the project. The bridge design was inspired by new techniques acquired in Czechoslovakia. The bridge opened in 1942, proving that Ostenfeld was able to successfully complete large bridge projects.

Shortly after the war, Ostenfeld sends an engineer to France to learn about prestressed concrete. This technique is further improved and adopted to the Danish climate. This development of prestressed concrete secures the company a leading international position in the years to come. Wriborg Jønson became an equal partner with Ostenfeld, and the company’s name was changed to Ostenfeld & Jønson - Rådgivende Ingeniører (Engineering Consultants) or O&J for short.

The company presents the world's first prestressed concrete silo called “the Ostenfeld silo”. It sets itself apart from other silos in that its walls, despite the silo's huge dimensions, are just 25 cm thick. Being prestressed, the walls can bear the pressure from within and remain totally sealed. With the huge market opportunities for silos in France, Ostenfeld & Jønson (O&J) opened its first international office in Paris. In 1957, O&J designed the Frederikstad Bridge in Norway, which was the company's first large bridge outside Denmark.

Ostenfeld & Jønson also designed both indoor and outdoor swimming baths all over Denmark, one of them being Bellahøjbadet in Copenhagen, which opened in 1960. During that decade, COWI assisted in constructing infrastructure, factories, hotels and wastewater plants in both Africa and the Middle East. In Scandinavia, O&J was the leading specialist within the building industry. In Denmark, O&J designed Glostrup Hospital, which was the most modern hospital in Europe at the time. 

In 1965, O&J was granted the design of the New Little Belt Bridge, which introduced new technologies such as analysis of the risk of ship collisions; an aerodynamic bridge deck; and specially designed anchor blocks that suited the difficult soil conditions. This project was a result of years of bridge studies in Europe and the US, and the technology was adopted to Danish conditions and combined with O&J’s own research.

In 1973, the owners W. Jønson, E. Kalhauge, P. M. Nielsen, E. H. Schülein, J. J. Jessen, K. Bergholt, A. G. Frandsen, S. Å. Rasmussen and H. Talbot-Pedersen converted Ostenfeld & Jønson into a public limited company under the name COWIconsult, Rådgivende Ingeniører AS, and transferred the share capital of that company to a foundation under the name "COWIfonden". At the time of the formation, the assets of the Foundation consisted of the entire share capital in COWIconsult, Rådgivende Ingeniører A/S. The name COWI is an abbreviation of the two senior partners’ names.

The oil crises of the 1970s affected COWI's operations because the Danish government put a stop to all major state construction projects. Nevertheless, possibilities emerged in the fields of energy and environment. Together with the Technical University of Denmark (DTU), COWI developed a so-called zero-energy house in 1974, which became an important study project in the future of green buildings. In Denmark, COWI became an expert in designing energy-efficient district heating systems, and COWI became the first engineering company in environmental consulting.

Our profile gradually changed, expanding to environmental consultancy, energy and planning. We built expertise in water treatment and became a trusted consultant for public authorities when planning public transportation and new environmental legislation. Indoor environments also become a COWI speciality. In Ebeltoft, COWI designed the world’s first offshore windfarm. Abroad, COWI designed large motorway projects in the Middle East and rural development projects in the Philippines.

The Great Belt Bridge closed the gap between the eastern and western parts of Denmark. COWI was awarded all three parts of the project: the railway tunnel, and the East and West Bridge. When inaugurated in 1998, the East Bridge was the second longest suspension bridge in the world. The railway tunnel was Denmark's first bored tunnel and faced several challenges. For example, the seabed under the Great Belt consists of huge rocks, sand, clay and chalk, which made the underground construction very difficult.

In the following years COWI carried out large bridge projects, such as Stonecutters Bridge in Hong Kong in 2009; Osman Gazi in Turkey in 2016; Mersey Gateway in the UK in 2017; and Hålogaland in Norway in 2018. 

Just two years after the Great Belt, COWI opened another grand project: the Oresund Bridge. COWI grew through new acquisitions in Scandinavia and the UK, doubling in size and consolidating our position within infrastructure. COWI became a truly multidisciplinary company with a long suite of projects within transportation, energy, waste management and construction of both hospitals and airports. Sustainability became the key to our consultancy with climate- and energy-friendly solutions enhancing our projects.

In 2010, a new group structure was set up with COWI Holding A/S as the parent company. COWIfonden is the majority shareholder in the parent company, which in turn is the majority shareholder – either directly or indirectly – of all the companies in the COWI Group. COWI designed the London Array wind farm in 2010, which kickstarted wind projects all over the world. The effects of climate change became imminent, and COWI handled projects within climate adaption and sustainable urban development.

Since 1994, COWI has been part of developing the Copenhagen Metro system. The first stage of the Copenhagen metro opened in 2002, and COWI was selected as a consultant for the design of the tunnels and stations as well as overall project management. In 2019, the City Circle Line project was inaugurated, bringing the total number of stations to 37. This made Copenhagen even more connected and explorer-friendly. 

During this year, traffic opened on this record-breaking bridge. With a free span of 2,022 metres, Çanakkale Bridge connects the European and Anatolian sides of the Çanakkale strait.

COWI acquired Mannvit hf., an Icelandic-based group of engineering companies with 280 employees and a stronghold in green energy. Mannvit provides consultancy services in energy, infrastructure and industry and has specialist competencies in geothermal and hydro power.

At any given time, COWI is involved in approximately 9,000 projects around the globe.