The British architect Norman Foster has won the prestigious international competition to remodel the 17th-century Hall of Realms as a new wing of the Museo del Prado in Madrid. The winning design, conceived jointly with the Spanish architect Carlos Rubio, beat submissions from museums favourites David Chipperfield and Rem Koolhaas on a shortlist announced in June. 

First proposed by the Spanish government in 1995, the project to restore the only surviving part of Philip IV’s Buen Retiro pleasure palace, which housed Spain’s Army Museum until 2005, has been hampered by years of austerity. The building was officially assigned to the nearby Prado last October. The plan was to open the 5,000 sq. m space in time for the museum’s 200th anniversary in 2019. This timescale now looks unrealistic, as construction will probably start in 2018, the Spanish newspaper ABC reports. The budget is estimated at €32m.

Foster and Rubio’s proposal is called Hidden Design and features a large “semi-open and permeable” entrance atrium on the south façade that will “protect the original façade”, whose windows and balconies will be reinstated, according to a press statement. A new roof topped with solar panels will give natural light to a large exhibition space above the atrium, overlooking the main museum complex. 

The Hall of Realms will present works from the Prado’s collection and temporary exhibitions focusing on key themes from Spanish history. The long-debated idea that Picasso’s Guernica (1937) could be moved there from the Museo Nacional Centro de Arte Reina Sofia has been firmly quashed by the Prado’s board.