The UN City (FN Byen) is located at Marmormolen and currently accommodates 1,200 employees from 104 different countries. The building was designed by Danish architecture firm 3XN, with a total of 45,000 m2 office space and 7,000 m2 basement and was inaugurated on the 4th of July 2013 by Secretary-General Ban Ki-moon and Her Majesty Margrethe II of Denmark. The building is built with a large focus on sustainability and environmental friendliness, and the calculated energy consumption for the building is less than 50 kWh/m2/year.