Recycled. Brick. Passive House

A small art museum in the equally small southern German town of Ravensburg, reorders the sustainable building agenda and Passive House orthodoxy

The distance, as the crow flies, between Germany’s two Southern capitals – Stuttgart in the South West and Munich to the South East, to the southern border region of the Allgau - is roughly equidistant, around a hundred miles. Both cities are home to large numbers of architectural practices, and both are centres for Germany’s hi tech ‘Vorsprung durch Technik’ industries and reputation. The Allgau, by contrast, is overwhelmingly rural and agricultural, dotted by small towns with medieval quarters, attracting tourists to its relative slower pace of life. It may come as a surprise therefore, that this quiet agricultural border country was home to one of the current five finalists of the European Union’s bi-annaul Mies Van Der Rohe Award for 2015. Not only this, but the project has already won a string of sustainability awards, burnishing it with an influence way beyond its Southern German pale. It’s a project, though, which stands some distance from the current centre-ground of sustainable orthodoxy.

The small, market town of Ravensburg (pop 50,000) may not be an obvious focus for sustainable architecture, but Ravensburg Art Museum by Stuttgart practice, Archbureau LedererRagnasdottirOie (or Arch LRO for short) has attracted a ripple of attention, first in Germany and latterly, across the continent. The reason? Well, one explanation is that Arch LRO’s Museum building is the first Passivhaus museum in the world. But this is only one aspect of its multi-award success. In 2014 among a string of further awards, the art museum won Germany’s National Architecture Prize. This was in addition to the German Passivhaus Award, the Wienenburger Brick Award, the Baden-Wurttenburg Recycling Award and the European Architecture and Energy Award.  And now in 2015, it was pipped at the post for the Mies award.

Garlanded with laurels such as these, the Ravensburg Museum’s success begs questions about what it is being awarded for.  Is its recognition as one of the Mies Award finalists, about architecture pure and simple, or does the buildings sustainability play a part? And if it is the latter, how does such a major award reflect on the Passive House movement? Is it, as it surely will be spun by those promoting Passive House, both a major step for the Passive House movement, and a sign of Passive House moving further into the architectural mainstream? Or, more obviously and generally, is the award more for its architectural value – (if also for its sustainability) – encompassed by the other awards but not defined as Passive House? Its inclusion on the Mies award list amplifies and broadens the interpretation of the building as a singular sustainability reference point, potentially re-imagining and re-defining the Passive House identity and narrative.

This is not to underplay the technical achievements. It is still a Passive House building, and the museum operates on Passive House principles achieving the usual very low air, heat and cooling levels. The design is, however, strikingly at odds with much of the building culture that has emerged out of the technical and energy pragmatist-led Passive House ideology. Indeed, the art museum, situated within Ravenburg’s old medieval quarter, is a vivid contrast to many Passive House preconceptions.

What is so striking, is the union of form, site and materiality, bearing next to no resemblance to the orthogonal cube that has become characteristic of many Passive House projects: heavily insulated boxes, designed out of and responsive to the workings of PHPP software.

Rather the museum sits calmly beside its immediate neighbour, a large medieval townhouse, its brickwork a fitting foil in the vernacular setting.  There is a clear sensitivity to the site, edging a right-angled corner, and exhibiting a careful restraint in the midst of the ‘Burgischer’ sensibility of the old town. Inside the modestly scaled building – three floors – Arch LRO’s sensibility is as fully evident as on the outside. This may be pioneering Passive House, but it speaks to a broader vocabulary, one that is distinctively identified with a studio led by half-German, half-Icelandic  studio partners. Completed in 2013, the museum’s external façade’s main material, recycled small red-grey brickwork echoes the subdued palette of its neighbours. Small in size, the recycled bricks announce these different intentions. The focus on materials and on materiality’s tacit dimensions, continue both inside, and in much of the detailing. While it employs Passive House kit, it is this rather different agenda that comes through.

Although Southern Germany is a part of the country where Passive House has embedded itself most strongly, Arch LRO aren’t a practice with a track record of Passive House projects, and during a phone interview with Arno Lederer, he speaks as if only semi-committed to the cause when characterising their sustainability ethos as focused on a “little more than only saving energy.” He continues” “We wanted to think more than this, to show where the materials actually come from. This is part of what we are very interested in, in materials durability. That materials are not expensive to repair, re-use is not so complicated, these sorts of things.” Within in its first year of opening, the museum had won the DGN Sustainable Building of the Year, a major national award, which highlighted the Passive House innovation, ironic given the original brief didn’t include any requirement for Passive House standards. And it was only when the main investor backing the museum asked, according to Lederer, if there was a way to integrate Passive House into the design, that it became part of the brief.

Bringing in specialist services engineers Herz & Lang to model the heat and ventilation, has resulted in a heating strategy, focused on a gas heat pump, and monitored through a Building Management System. This BMS also controls a heating and cooling distribution system running the air-conditioning equipment necessary for the highly sensitive temperatures art museums need to be maintained at. Together with its compact form, along with heavy insulation, the strategy ensures a thermal performance that maintains the concrete slabs at a steady 22°C.

Respected in Germany, LRO are positioned somewhat left field and at odds with the sort of high-tech practices that are architecturally, Lederer believes, as much in evidence, as motor engineering, in Stuttgart. He cites the likes of Werner Soebek, the Behnisch practices and Transolar: “they like to deal with these technical things.”  Arch LRO are, he thinks, a minority in the city – “there are less architects who think like us,” by which he means the concern for materials, for durability, for re-use. The Stuttgart tech practices are pursuing an old, and he believes, outdated architectural dream; sci-fi futurism, high tech and futuristic materials. “In the last half of the twentieth century, architecture had this idea of the future, which could solve all sorts of problems through technology.” He thinks this is now changing, and that there is a different idea of the future emerging. “I don’t want to say traditional… but it is about more than technique.” Lederer, who is in his mid-sixties, attributes his minority path to early post-student days working at the Swiss practice of Ernst Gisel. In Switzerland, it was Gisel, who amongst the emergence of a post war Modernist generation was one of the few to pursue the organic architectural lineage of Lloyd Wright and Aalto most intently, in contrast to the dominance of Mies and Le Corbusier on the Swiss-German scene.

“It’s good for the architecture”, he adds, a soft German accent coming down the line, “when you don’t need all the hi tech material, but the common, traditional and the human.”

The Ravensburg museum re-uses materials liberally. After overcoming initial scepticism about their approach, Arch LRO’s obvious sustainability dimension won round the more cautious voices on the project committee. The lovely burnt ochre, reds and dusty, sandblast colourings in the brick façade walls, were imported from a demolished Belgian monastery. Recycling brick is the most obvious re-use, although a significant amount of the concrete was also recycled. Re-use and its use in the Ravensburg building is particularly significant in the German context, since regulation generally forbids – as this example, shows - its application to public buildings. Unbelievably - to this foreigner at least - Lederer states there is next to no recycling industry in Germany. The Ravensburg museum fuses the studio’s sensibility with an explicit sustainable agenda, continuing and building on the practice’s past. The circumstances around the museum were different, he acknowledges, but the approach continues what Arch LRO are known for. “There’s a similarity, which is to do with the industrial methods we’ve used. That’s what we like, we like the good and the handcrafted. We like to use it, and we want to use it, and not to lose it.”

He points to some of the subtler aspects of LRO signature “little details” and talks about arranging the guttering to run in an open gutter, so that anyone can see how the rainwater runs down the buildings side. There are other details which he is obviously pleased with. The door handles, for instance, was designed in-house, - “which we like to design ourselves” - are designed in tandem with the museum’s entrance doors.
The extent to which the refinement of the all brick exterior has prepared the visitor for what awaits inside, isn’t immediately clear. Those anticipating white cube orthodoxy will not be disappointed; both the ground floor entrance and the first floor are full on white, though oblong rather than cube. A film screen wall, at the far end of the ground floor – providing a break for children, and other activities to be carried out on its far side, out of view if not out of sound.

If the ground and first floors are all white cube orthodoxy, resulting in a total absence of natural light and windows, climb to the museum’s top third floor gallery space, and here you arrive in its most dramatic chamber. Above the white walls and on the roofs underside, are a series of brick barrel vaults, the horizontal lines alternating in a cats cradle rhythm. “That is what we like very much”, Lederer notes. “We say there are three possibilities for how a building will end, with a pitched roof, with a flat roof and with the vault. And the vault gives a good feeling.” Lederer references the revered Swedish architect, Sigurd Lewerentz’s Klippan church building and the Prussian Kappendecken tradition, before noting how all the bricklayers were from the Allgau. As with these examples of other Modernist buildings, Lederer’s work exhibits a concern for interior architecture and detailing, and as an architect, his desire for a closer relationship with building expresses itself in very close attention to detail, in effect, through craftsmanship

The use of the barrel vault follows on earlier precedents. In central Stuttgart Arch LRO’s were commissioned to design an extension to Kammerer Belz (one of Lederer’s student practices) sizeable black brick office for the EVS energy company. Through rethinking this Bauhaus throwback building’s top floor, Lederer and Co moved the original restaurant from underground, up onto the previously open courtyard, opening up the ceiling with a sweeping brick barrel vault, and supporting columns, between well sized light well windows. “It works” says Lederer of the EVS precedent, before concluding; “A very nice building and a very nice room.” In this building, the architect was stretched to find skilled enough German bricklayers to carry out the work, with the result that Polish bricklayers who retained these skills, were employed.

Inside the museum, there are other surprises, the stairwells to the two upper floors, provide the only play of light, almost a miniature light exhibition or artwork in itself, with the light rippling onto the far walls of the well through the square windows. When I mention this to Lederer, he laughs, happy to acknowledge that this was hardly unintentional. There are two rows of windows on each of the storeys, compensating for the complete dark of the interior windowless gallery rooms. Clad in copper, the entire roof, adds solidity and vertical order. Down the staircase to the museum’s other end, the lower ground floor, the passage-way space is painted a rich earthy brown.  The toileting facilities have also been placed on the lower ground floor, this time exuding an equally warm orange, and suggesting a practice sensitive to the subtleties of colour.

Ravensburg Art Museum is the most sustainable building to have made it onto the Mies Awards finalist lists over the last decade. The award, which was inaugurated in 1983, has been criss-crossing Europe ever since. While its shortlists include the smaller and out of the way, the main prize has gone to a role call of the mainstream and obvious; the last three bi-annual awards have all been to showstopper cultural projects; HenningLarsen’s Reykjavik Harpa Concert Hall in 2013, David Chipperfield’s Berlin Museum in 2011, and Snohetta’s Oslo Opera House in 2009. That Ravensburg was a 2015 finalist, reflects the inroads sustainability, including Passive House has made into the heart of European architectural culture. Conversely Arch LRO’s museum demonstrates what is architecturally possible, when designing within Passive House parameters. More generally, the remarkably high profile given the museum through its many awards ought also to broaden the debate around the future shape and character of sustainability. The tactile and hand-made aspect, the relation to light and colour, all part of the studio’s DNA, can be equal to the museum’s technical appeal. Coming at an interesting moment in the evolution of the sustainable building industry, and although a modest cultural building in a small far from the centre part of Europe, Ravensburg Art Museum exists outside the standard categories. By doing so it helps propel debate beyond the usual parameters of what is possible.