Innovations across generations

The entrepreneurial history of the Ahlmann family in Germany dates back to the 19th century. In 1883, Danish merchant Johannes Ahlmann took over as commercial director of the Carlshütte iron foundry – the first industrial enterprise in the duchies of Schleswig and Holstein. With this step, he laid the foundation for an extraordinary family history. In its fourth and fifth generations, the company ACO has shaped a new form of global family business.

ACO, ‘Ahlmann und Co.’, is known today as the world market leader in water management.

On 10 December 1946, Severin Ahlmann registered his own company with the Chamber of Industry and Commerce in Kiel. Severin Ahlmann-Betonindustrie (SAB) initially specialised in concrete products for the construction sector. In addition to cement roof tiles, it manufactured building materials and products for civil engineering. Ahlmann quickly added Carlshütte's artificial stone (marble grain) products to its range and began manufacturing sanitary products. Severin Ahlmann's mother, Käte Ahlmann, wrote in a letter to a friend on 17 December 1946: ‘You can see the new company on this sheet. May it be successful!’

ACO took its first steps towards internationalisation back in the 1970s. In 1973, the first production facility for ACO DRAIN was launched in Mitlödi, Switzerland. This was followed in September 1977 by the start of production at ACO France in Notre Dame de L'Isle. In June 1978, ACO ventured across the pond with production in Chardon, Ohio. In the 1980s, Hans-Julius Ahlmann worked to ensure that these foreign activities became wholly owned subsidiaries of ACO and drove internationalisation forward with particular intensity. The fall of the Iron Curtain finally opened the way for ACO to enter Eastern European countries. Over the following decades, the company grew far beyond Europe and opened sister companies in more than 50 countries. Always with the aim of being as close as possible to the challenges faced by its customers.
ACO's global strategic growth

Hans-Julius Ahlmann officially joins his uncle's company.
At this point, ACO is an up-and-coming manufacturer of drainage channels. Building on this foundation, the young entrepreneur succeeds in establishing one of Europe's leading brands and, over the years, developing ACO into a global market leader.

Strategic acquisitions are one of the key factors in ACO's success. In 1997, ACO took over the renowned Kaiserslautern casting and fittings factory, known as ‘AWK’ for short.
Today, this factory is one of the most sustainable foundries in Germany and goes by the name of ACO Guss.

The next step in the family history: Iver Ahlmann officially joins the company, continuing the tradition of entrepreneurial responsibility into the next generation.

Shortly afterwards, ACO is named one of the TOP 100 innovators.
Iver Ahlmann, an aerospace engineer, plays a key role in driving forward material development. ACO specialises in the production of five high-performance materials – with a clear mission: the right material for every application!

In 2022, Hans-Julius Ahlmann will be awarded the World Economy Prize for this entrepreneurial achievement.

During this time, ACO is already undergoing a transformation: from a pure manufacturer of individual products for collecting, cleaning and storing rainwater and wastewater to a provider of sustainable, integrated system solutions. For the reuse and recycling of our most valuable resource.
The goal: to completely replicate the natural water cycle.

In 2025, UNESCO will honour ACO's long-standing commitment to protecting the valuable resource of water as part of World Engineering Day. ACO becomes the official ambassador for UN Sustainable Development Goal #6: Clean Water: ACO as UNESCO partner for SDG 6 - Watch the video

This year, Hans-Julius, Johanna and Iver Ahlmann were inducted into the Hall of Fame as new members – in recognition of their joint entrepreneurial commitment and their formative role in the development of the ACO Group. The award honours outstanding entrepreneurial achievements, sustained commitment across generations and the exemplary role of family-run companies in Germany.

“As a family of entrepreneurs, we are naturally very proud of this award. Now, in 2026, ACO's 80th year, we look back on the many key events that have led to us receiving this award. In this sense, the entire ACO family can be very proud, because it was always a group of people who worked together to achieve something significant.”

Hans-Julius Ahlmann
Managing Director