Washington DC’s National Gallery of Art has reopened its East Building following a three-year, US$69m (€61.5m, £54.2m) renovation process.

The I.M. Pei-designed building gains an additional 12,250 sq ft (1,140sq m) of floor space, split between two new galleries to house the works of Alexander Calder and Mark Rothko, and a new rooftop terrace.

Katharina Frithsch’s Hahn/Cock – a giant blue sculpture of a cockrel – sits on the new terrace after moving from London’s Trafalgar Square where it resided between July 2013 and February 2015.

Movement through the East Building has also been improved, with a new stairway and elevator installed to better-connect the different levels of the museum. The flooring has also been replaced.

The US$69m (€61.5m, £54.2m) renovation was funded in-part by the federal government, which granted US$39m (€35m, £30.6m). The remaining US$30m (€26.7m, £23.6m) was sourced through private donations. Washington-based architects Hartman-Cox were in-charge of design for the renovation work.