In 1923, a family business was established to carry out work relating to the building of fire-fighting installations and water pipes.

In 1935, the family business was transformed into a joint-stock company for the purpose of carrying out substantial water pipeline works and civil engineering works.

During the 1950s, the company specialised in pipeline work, executing important projects for NATO in northern France and Belgium.

In 1962 the company was integrated into Compagnie Générale des Conduites d'Eau in Liège, bringing the parallel interests of the two companies in line with each other.

When natural gas was opened up in the Netherlands in the mid-60s, Denys was ready to construct the most important gas transport pipeline in Belgium for Distrigas. The tunnelling department was launched at the end of the 1960s to meet the demand for No-dig techniques.

In 1976 the company was restructured and all activities concentrated in Wondelgem with subsidiaries in Liège and Oelegem, near Antwerp.

During the 80s the division 'Special techniques' was founded. Nowadays this division is one of the most important restoration companies in Belgium.

In 1983 COBEPA sells her minority participation to SOGEA-Paris, who in 1988 passes from the group Saint-Gobain to the group SGE (Société Générale d’Entreprises) who is for 15% controlled by VIVENDI.

In the mid-90s, Denys launched a railworks department within the context of substantial investments relating to infrastructure and mobility.

In December 2000, the DENYS Group was taken over by Johan Van Wassenhove together with representatives of the management and independent investors.

After more than 24 years the companies are in Belgian hands again.

Since 2001 the activity abroad is in full expansion, especially within the markets of “Water Works” (complex projects in drinking water supply and water treatment) and of high pressure pipelines (gas and oil).

From its roots as pipeline builder, the company has gradually also begun specialising in civil engineering. Within this branch and grown from the restoration division, Denys starts in 2005 with the construction of buildings. Since then, a fully-fledged Building Works division was born.

Currently the group DENYS employs more than 2500 people. 60 % of the activities is realized abroad.