The “urban window”, as it is referred to, is part of the striking new building designed by Paul Bretz Architectes which from October 2018 will be home to Deloitte.

The terrace is comprised of two concrete sails, weighing 48 tonnes, and a 50-metre-tall metal structure to cover the window, all of which were lifted into place by a mobile crane. The terrace, located between the seventh and thirteenth floors, spans some 400m2.

A longer version of this article can be found on Archiduc.lu