David Chipperfield restores Mies van der Rohe designed Neue Nationalgalerie, Berlin

As one of Ludwig Mies van der Rohe's last projects, the Neue Nationalgalerie (New National Gallery) in Berlin is often discussed as an assimilation of Mies' ideas. One can read the development of form and concept from the Tugendhat House to Farnsworth House to the Crown Hall all within the structural language and materiality of the museum. The fact that the museum can be read as a scaled version of the Barcelona Pavilion is a testament to the impact and influence his aesthetic had on 20th century modernism in architecture. Having immigrated to the United States in the late 1930s, the invitation by the Berlin National Gallery to construct this new structure for modern art allowed his practice to come full circle before his death. It has been more than 50 years since the building was completed, and in 2015 the museum was shut to carry out an extensive restoration and renovation process. This was undertaken by David Chipperfield Architects and reopened in April 2021. The refurbishment hopes to grant the Neue Nationalgalerie a new lease of life.

The museum may seem like a glass pavilion but this constitutes a small portion of the overall building. A more traditional white-cube gallery space is located underneath the glass pavilion. This basement style gallery also has large windows along the western façade, which opens up into a sculptural garden. The gallery can be seen as two distinct spaces across the two levels, a glass pavilion and the white-cube gallery. The glass pavilion was often used for temporary exhibitions, however, the granite finish in the space made it particularly hard for curators to work with the light quality of the space.

The structure has all the markings of Mies' work. The entire structure is based on skin and bone architecture, where the structural members of the building are independent of the façade. The glass facade envelops the entire building in a transparent skin, while the interiors are primarily finished with granite and marble. While Mies has been credited as one of the people to have popularised the aphorism ‘God is in the details’, the detailing of the Neue Nationalgalerie did not stand the test of time. The primary task of the refurbishing project can be summarised in this official statement by David Chipperfield: “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”.

Equipped with the wisdom of 50 years of use, the surgical refurbishment addressed some of the technical defects that the structure was experiencing. There were public safety concerns as the steel holding the glass was corroding and the thickness of the glass itself was underspecified. The structure was also constructed using material we now know to be hazardous, namely asbestos and artificial mineral fibres. While these were commonly used in the 1960s, they had to be completely removed and replaced. As part of this restructuring, the façade was refitted with a laminated safety glass, which is two times thicker than before. The method used to connect the roof to the façade was changed so that the façade could be adapted to move without constraint. For this purpose, short steel struts replaced the continuous flat steel around the mullions.

The newly incorporated mullions absorb the movements of the structure. These are designed to be airtight and vapour-tight to prevent corrosion inside the profile joints and cavities.Proportions were an integral part of Mies’ work, the ratio of the mullions grid to the structural grid were meticulously designed and planned. The non-invasive upgrades had to be mindful of this. Alexander Schwarz, Partner und Design director, David Chipperfield Architects, Berlin, summarised it best saying, “It was all about preserving the aura and not about the reinstatement of an image. The refurbishment of the Nationalgalerie fundamentally accepted ageing and traces of use in the existing building fabric, as long as they did not impair the visual appearance and usability of the building”.

Considered an architectural monument, the granite façade of the Neue Nationalgalerie at the podium was one of the first ventilated natural stone façades installed in Germany. It was therefore important to the restoration process to reuse the historic granite slabs and ashlars. All the façade slabs were dismantled and repositioned in their original location. The removal was required to renovate the concrete shell, sealing and replacement of the thermal insulation. Before repositioning the historical slabs, the reusability of the natural stone as curtain walls was verified and tested. Broken slabs were replaced to maintain the aesthetic and stability of the museum structure.

Despite the extreme nature of the structural deficiencies, contemporary technical solutions made it possible to remedy the situation while maintaining the unique façade and legacy of Mies van der Rohe's work in Germany. The details of the refurbishment project read like a parable of the Ship of Theseus that uncovered Mies' attention to detail leaned more towards the appearance and proportions of the space rather than the usability. The refurbishment has been detailed in an essay by Martin Reichert, Partner and Managing director, David Chipperfield Architects Berlin, titled "Monument preservation and renewal concept". A passage from the extract reads:

The outstanding importance of the Neue Nationalgalerie, representing the climax and conclusion of late Modernity, and its almost undisturbed material and visual preservation, placed high demands on monument-preservation compatibility of the building measures. The perfection of the “temple of Modernity” affords hardly any leeway and is unforgiving.

The building measures focused on the general overhaul of the structure, including the removal of toxins and achieving contemporary technical and energy-related standards–in so far as this was compatible with the demands of the monument. The client’s defined goal, “As much Mies as possible,” as well as the building’s given limits and potential, left little room to manoeuvre. Firmly in the spirit of the task, our team at David Chipperfield Architects regarded ourselves as “invisible architects,” who planned and implemented the required adaptations and measures in the service of and with a responsibility toward the original designer, Ludwig Mies van der Rohe, thereby refraining from incorporating our own personal preferences.

The essay will appear in the book Neue Nationalgalerie Berlin. Refurbishment of an Architectural Icon. Edited by Arne Maibohm for the BundesamtfürBauwesen und Raumordnung. To be published in July 2021 by JOVIS. ISBN 978-3-86859-687-8.

Tap on the cover video to hear Curator Esenija Bannan in conversation with British Architect David Chipperfield. The video is part of Bannan's ongoing film and exhibition project  Mies Goes Future, a long-term study, inviting artists, architects, art and architecture historians to explore the possibilities of how the future of the Mies van der Rohe House as an institution can be shaped.