The firm quickly became known for creating buildings of substance with compelling aesthetics supported by a strong theoretical foundation.

The international breakthrough came in the late 90s with the Danish Embassy in Berlin (1999) and the Muziekgebouw Concert Hall in Amsterdam (competition win in 1997).

In Denmark, 3XN is known for such projects as Ørestad Gymnasium (2007), the renovation of Tivoli’s Concert Hall (2005), Alsion, university, concert hall and research centre in Sønderborg (2007), Hotel Bella Sky (2011), UN City (2013), Denmark’s National Aquarium, The Blue Planet (2013), Royal Arena (2017) and Lighthouse in Aarhus (2022).

In 2007 3XN established the research and development department GXN working on implementing new (green) materials and technologies in the studio’s projects.

In 2010 3XN created the exhibition Mind Your Behaviour, which was shown at Danish Architecture Centre and at Aedes Gallery in Berlin.