Nearly a decade after being appointed to refurbish one of Modernism's most iconic buildings, the team of architect David Chipperfield wrapped up construction on the Neue Nationalgalerie in Berlin.

In a recent virtual ceremony, the keys were handed over to the clients — Berlin State Museums and Prussian Cultural Heritage Foundation — and the building is being readied now to re-open to the public in August with an exhibition of Alexander Calder sculptures.

The gallery, which first opened in 1968, is the only building designed by German-born architect and former Bauhaus director Ludwig Mies van der Rohe in Europe after his emigration to the United States in 1937.

"The existing building fabric has been refurbished and upgraded to current technical standards with a minimum of visual compromise to the building’s original appearance," notes a statement from David Chipperfield Architects. "The functional and technical upgrades include air-conditioning, artificial lighting, security, and visitors’ facilities, such as cloakroom, café and museum shop, as well as improving disabled access and art handling."

"The necessity of an extensive repair of the reinforced concrete shell and the complete renewal of the technical building services required an in-depth intervention. Around 35,000 original building components, such as the stone cladding and all the interior fittings, were dismantled to expose the shell construction. After their restoration and modification where necessary, they were reinstalled in their precise original positions."

"The key to the complex planning process for this project was finding a suitable balance between heritage conservation and the building’s use as a modern museum. The unavoidable interventions to the original fabric within this process had to be reconciled with preserving as much of the original substance as possible. Though the essential additions remain subordinate to the building's existing design, they are nevertheless discreetly legible as contemporary elements."

Reflecting on the significance, and challenges, of such a commission, David Chipperfield commented: "Taking apart a building of such unquestionable authority has been a strange experience but a privilege. The Neue Nationalgalerie is a touchstone for myself and many other architects. Seeing behind its exterior has revealed both its genius and its flaws, but overall it has only deepened my admiration for Mies’ vision. Our work was therefore surgical in nature, addressing technical issues to protect this vision. Certainly carrying out such a task in a building that leaves no place to hide is daunting, but we hope to have returned this beloved patient seemingly untouched except for it running more smoothly."