Foster + Partners Completes Bilbao Fine Arts Museum Expansion

BILBAO, SPAIN: Foster + Partners and architect Luis María Uriarte have completed Agravitas, a major transformation of Bilbao Fine Arts Museum that places a new gallery structure above the institution’s historic buildings while creating additional exhibition and public space below.

The project was officially marked by a reopening ceremony on October 5, 2026, introducing a new architectural layer to a museum complex that has developed through several periods of construction since the mid-20th century.

A new gallery above the historic museum

The new addition sits above the museum’s 1945 building and its 1970 extension, introducing a large flexible exhibition floor while preserving the historic structures below.

According to Bilbao Fine Arts Museum, Agravitas provides 6,743 square metres of new construction and includes the refurbishment of a further 8,000 square metres of existing space. The overall intervention increases the museum’s built area by more than 60%.

The elevated structure is characterised by a fluted exterior and a limited number of large supports positioned away from the footprints of the older buildings. These supports allow the new volume to appear suspended above the museum, giving the expansion its distinctive profile.

Plaza Arriaga becomes the heart of the museum

One of the main changes takes place at ground level, where Plaza Arriaga has been transformed into a covered public space connecting the different parts of the museum.

The approximately 1,000-square-metre area now functions as a central arrival and circulation point, linking the museum’s entrances and galleries while also providing space for art and public activity.

The redesign also reopens the museum’s original 1940s entrance facing the city square, restoring its role as one of the principal access points to the building.

A large circular oculus links the elevated extension with the atrium below, bringing daylight into the central space and creating visual connections between the different levels.

More flexible space for exhibitions

Agravitas significantly expands the museum’s exhibition capacity.

The upper levels provide around 2,300 square metres of flexible exhibition area across two floors, including a large column-free gallery designed to accommodate temporary exhibitions and artworks of different scales.

Bilbao Fine Arts Museum states that the expansion provides an additional 1,635 square metres for the permanent collection, representing an increase of around 45%. The new BBK Museoa space and adjoining terrace together cover approximately 2,200 square metres.

Educational facilities, workshops, offices and research spaces are also incorporated into the expanded complex.

Connecting different generations of architecture

The Bilbao Fine Arts Museum has evolved through several architectural periods.

Its principal historic building dates from 1945, while a modern extension was added in 1970 and further alterations were completed in the early 2000s. Agravitas is designed to connect these different elements rather than replace them.

The project also improves movement across the site, making the ground floor easier to navigate and strengthening connections between the museum, nearby streets and Doña Casilda Iturrizar Park.

The completed expansion was designed by Foster + Partners in collaboration with Bilbao architect Luis María Uriarte.

Project: Agravitas – Bilbao Fine Arts Museum Expansion

Architects: Foster + Partners and Luis María Uriarte

Completed: 2026

New construction: 6,743 sq m

Photography: Nigel Young