Epstein provided architect and engineer record services in conjunction with design architect Jahn (formerly known as Murphy/Jahn) for the recently completed Cosmopolitan Tower, a high-profile mixed-use development located on Twarda Street in the center of Warsaw, Poland. This 44-story high-rise tower includes 252 high-end apartments, office & retail space, as well as an underground parking garage.

The tower includes 252 apartments ranging from 52 to 350 square meters. Cosmopolitan Towers ground floor along Twarda Street provides commercial space for shops and services and its underground part has been designed to accommodate a 300-vehicle car park.

The Cosmopolitan Tower was completed in the summer of 2013 and is currently the second tallest residential building in Warsaw and third tallest in all of Poland.