CONTEXT AS A SCOPE FOR ACTION.
APPROACHING RENOVATION WITH AN EXPANDED DEFINITION
In architectural practice, the word «context» is typically used in the sense of «urban planning» and applied to any form of surrounding more or less adjacent to the building area. The context is already there. Meanwhile,
architects have become rather skilled in adopting their own interpretations of the word. Unfortunately, the urban context often complicates planning for the architects, for example by lacking uniformity, sending out contradictory signals, or simply by being banal.
For this article, the term will be streamlined—or expanded, depending on the point of view. Whoever ventures a building renovation, risks reducing his focus to the singular project at hand and, at the same time, expands it to include the very cosmos which the building already represents. In planning for existing structures—from maintenance to repair, conversions and extensions, all the way through to interventions that involve a replacement building—it is not just the neighboring houses, streets, and other structures that are given factors, but most importantly the building that is undergoing alterations itself. It should be modified in keeping with modern times. Briefings may be peppered with talk of changing «requirements,» or «more stringent standards and regulations.» In short, this means practical constraints. And beginning with the static elements, the windows, the points of access, decoration, right through to the people that have lived in the house, will be living in it in future—might, in fact, continue to live there even during the construction works—all the user requirements must be kept in mind.
What a context may entail can be understood by examining the architects’ description referring to the redevelopment of the Glanzenberg housing complex in Dietikon:
«In both of the residential towers, the tasks encompassed a renovation of the building’s exterior walls improving its thermal insulation, a moderate renewal of the technical installations, bathrooms, and kitchens, including pipe restoration. Noise mitigation for the high-rises, since they are located between the railroad tracks and the much-traveled main road, also had to be addressed. In the apartments, efforts had to be made to effectively improve
the space even with modest adjustments. The inconvenience of the repairs
and conversions to the inhabitants still living within the buildings had to be
taken into account as well.»
Gushing out like a cascade, all of today’s usual renovation requirements come to light here: the only two points missing are the adaptation to the new earthquake codes and any mention of the costs. We can rightly assume
that these would have been kept within a tight framework for a building cooperative such as the Dietikon project. Despite this limitation, the building has an entirely new appearance today. Not only the interior layout but also the facades have been redone: the towers gleam in bright red and orange colors above the Limmat Valley, much as landmarks and symbols of change for a formerly abandoned stretch of the urban periphery. The following descriptions of interventions in six school and residential buildings will demonstrate how Dietikon–Glanzenberg literally «showing off» its renovation proves it the exception to the architects’ usual production, and yet the project is typical of the methodology of Galli Rudolf Architekten.
Every project has its unique character, and there are no set rules. Renovation projects in particular reveal the interests and strategies of architectural offices: what the works presented here have in common is the architects’ integrated approach to the object and the task. Seasoned expertise enables the architects to approach even the most complex problems prudently and to set new markers in some instances. The experienced practitioners tackle
their work with impartial curiosity and a clear strategic approach. A goal is formulated, and the path to reach it is continuously reassessed along the way to determine whether the players are still firmly on course. The main aim is to discover and subsequently define which of the little pieces are crucial for the big picture—without getting bogged down in details. Not the journey is the destination—the destination is.
INTEGRATING A SCHOOLHOUSE INTO THE CITY: ZURICH TECHNICAL COLLEGE
The renovation and conversion of Zurich Technical College 2006—2008 serves as a fine example of Galli Rudolf Architekten’s renewal strategies. This building, completed by architects Eduard del Fabro and Bruno Gerosa in 1962 stood as the paramount example of the work of the erstwhile architectural partnership— along with their Looren schoolhouse. (1) An important testimony to Swiss postwar modernism, it shows typical features, like a stark presence in the urban fabric, formal rigor, a sophisticated routine with module and grid, and a curtain wall as a representative hallmark. Yet it is entirely different from the Freudenberg school, which, while erected at almost the same time by the young Jacques Schader, has broad and flowing intermediary rooms and circulatory options. By comparison, the Technical College lacks one key element: the generous and inviting space of an open entrance. Along with the School of Design (today Zurich University of the Arts), other vocational schools, and the Limmat primary schoolhouse, it should have become part of Zurich’s new «Education Mile,» but it was missing a connection of the ground floor to the surrounding public space.
Galli Rudolf Architekten took the complete renovation as a chance both to examine the schoolhouse more closely as an entity, and to carefully consider its overall functional coherence. The triggering factors for the renovation were numerous and pressing issues such as groundwater that had been seeping into the basement since construction, the precarious condition of the rusted facade elements, a seismic resistance that did not meet modern codes, and overall outdated facility services. Several spaces were to be newly organized, and the smallish classrooms and some of the workshops on basement level were to be eliminated.
«Less is more,» the famous adage chosen as code phrase for the winning competition entry determined the strategy: the architects rejected the notion of a controlled ventilation system and instead presented an alternative solution for the building services. The original appearance of the glass blocks in the upper floors’ corridors could thus be retained with newly produced glass blocks. To realize additions to the floors in the authentic look of terrazzo stone plates, a former quarry was reactivated. In the course of the reconstruction of the flat roof, the caretaker’s apartment was gutted, and two chemistry labs were installed in the attic floor instead. Most importantly, however, the architects solved the problem of the lack of public space on the ground floor by radically changing the spatial sequence. The layout now not only differed from the original building but also from the competition brief. The masterstroke in this case was to situate the cafeteria next to the auditorium on the ground floor of the main building—rather than in an adjacent wing as was originally planned. Working under considerable cost pressure and with extraordinary care, both the building’s interior and exterior were renovated as closely to the original as possible, and the room layout of the ground floor was programmatically redefined without changing the exterior integrity of the building.
Galli Rudolf Architekten succeeded in accurately reading, understanding, and advancing the grammar of postwar architecture. The originally already glazed entrance area was gutted and newly designed to create an open vista through several room layers, through the all-but-forgotten inner courtyard and out towards the new cafeteria. One layer further on, the erstwhile mechanical workshop was transformed into the new auditorium, which—together with cafeteria and courtyard—now comprises the central tract open to the public.
The architectonic details were critical to the overall impression of the Technical College—and therefore to its urban relevance. The small-paned aluminum windows from the 1950s were carefully redesigned to meet today’s energy efficiency requirements. Some of the facade elements had to be stabilized by new anchoring, which was done so masterfully that the change can hardly be noticed. Such obstinate attention to detail is no mere fad; it is both beholden to the building’s structural heritage and—through the insistence on quality—ensures its sustainable future. While, thanks to its «facade lift,» the building today appears fresher, perhaps even more «authentic» than before, the most surprising effect the newly arranged ground floor imparts is the fact that it hasn’t actually been this way from the start.
(1) In 1953 the open competition for a new building for the Technical College in the city of Zurich was decided in favor of del Fabro and Gerosa. The main wing and the first wing housing the workshops were built between 1959 and 1962, the second workshop wing was added later on, between 1965 and 1967.
SECURING OF EVIDENCE, SETTING A MARK:
THE BÜHL SCHOOLHOUSE
Similarities to the renovations of Zurich Technical College can be seen in the architects’ approach to the refurbishment and different conversions of the gym facilities and school wings of Bühl schoolhouse in Zurich-Wiedikon between 2001 and 2004 . Here, too, the interventions were integrated into the context so subtly, they are hardly visible at first glance, but once noticed they are all the more impressive. The three-part neo-Gothic school complex sits enthroned on the rise above Wiedikon’s Bühl neighborhood, and the buildings feature elements typical of their time: heavy quarry cornerstones, polychrome painting, delicate roof edges, and slate roofs. Not surprisingly, the schoolhouse is listed in the inventory of Zurich’s heritage buildings of communal significance.
As a direct result of this listing, the renovation works left hardly any visible traces on the building; new elements are limited to the interior. With the new tiling of the slate roof and the restoration of the natural stone facades, also the proportions of the roof edges and the window profiles were carefully retained, and the contrasting colors of the frieze paintings were duly restored. An exception is the pavilion of exposed concrete that the students use during recess; the architects placed it near the main tract A. The carefully molded concrete object is adjacent to the schoolhouse, but it appears as an independent edifice and discreetly structures the whole ensemble.
Like the schoolhouse in the inner city, the Wiedikon project needed a clear-cut and integrated strategy for the renovation of both the gym and school tract C (2001—2003) and for the uppermost story in tract A (2004). Rather than housing classrooms, tract C shows a symmetrical layout with two lateral gymnasiums and a small, 3.5-story gable-roofed house at the center. In addition to the necessary measures to preserve the building’s structure, which also included the discreet integration of fabric awnings over the windows as sun protection, and the careful renovation and technical update of the two gymnasiums, important decisions were to be taken—as a last point of similarity to Zurich Technical College—regarding the entrance area. The much needed addition of an elevator made it possible to open up the whole layout. The architects removed a wall that had been added to the original space and replaced it with a cast-iron column; this generously opened up the entrance hall, both physically and visually. The black column now marks the center of the building, and while it seems heavy and voluminous in its base and unadorned capital, an exaggerated entasis of the body and the taper — both of the column’s base and the abacus—lend a certain dynamic to the whole space. An architectonic object in itself, the column simultaneously adapts to and becomes part of the structure. It assumes a clear formal language, yet carries no definite signature — very much in the way a renovation of an existing structure should be.
This idea of «working on and working with the building» is continued across all other stories and in both gymnasiums. Particularly the upper stories—radically altered over the decades to meet the ever-changing demands
of new uses—could be newly arranged in a surprisingly simple way. The relatively small area of each story provided an ideal starting point for a time-tested principle of organizing living space that, in fact, dates from the Gründerzeit period, the last third of the nineteenth century: all rooms are arranged around and can be accessed from one central room. This room has been refitted, like a suitcase with a new lining, and now features updated building services, while its hard, smooth walls visibly call attention to the alteration. Together, the old and the new structures create a natural and harmonic whole. Likewise, the lighting in the stairwell is clearly new, but it is effortlessly integrated into the older surrounding.
The addition of the library in tract A followed the requests to provide a proper library facility for the twenty-one classes. Since no classroom could be made available to suit this purpose, and the budget was limited, the library was installed on the top floor, under the roof. The actual alteration consists of the eggshell-white bookcases that stretch the full length of the corridor’s south wall. Glass panes inserted into the original, dark pine doorframes helps retain the ambience of the historic interior, while new visual trajectories were created, and the whole space now adheres to the required fire protection codes. The works on the building clearly stem from a conciliatory approach to the existing structure that is marked by respect and careful differentiation. This new understanding of built heritage preservation aims to unite the spheres of old and new—but that was not always the case.
RENOVATION: A WICKED PROBLEM
A century ago—even before modernism—the very first heritage preservationists postulated that any new architectural elements should be clearly distinguishable from the old, pre-existing ones. They argued that the old structures were unique artifacts of art historical value, and the purity of the authentically antique should not be violated on any account. While on the first «Day of Heritage Preservation,» celebrated in 1900, the notion of accentuating the difference between old and new was still a novel perspective, it was an approach the majority came to accept within fairly short order. (2) The modernists of the 1920s and 1930s were eager to take up this position: their buildings wanted nothing to do with the past. The slogan of the «new building» movement is clear enough, even if many of these object-buildings stood in pre-existing built environments. The Venice Charter of 1964, the international framework for modern-day built heritage preservation, set down the dogma of the contrast between old and new. In Article 12, it expressly demands that,
«Elements that are intended to replace missing parts, […] must harmonize with the whole, but must remain distinguishable from the original corpus, so that the restoration does not compromise the value of the monument as art and historical document.»
Should an alignment prove impossible, Article 9 dictates that there be a readily readable differentiation,
«In the case of a hypothetical reconstruction, every supplementary element, whether considered absolutely necessary for aesthetic or technical reasons, should count as an architectonic composition and reveal the character of our time.» (3)
With the increase in the number of buildings needing renovation, a routine developed, as, on the other hand, did a new perception of the relationship between old and new. Since the 1990s, a large number of architects discovered—and this is where Galli Rudolf Architekten play a pivotal role with their renovation strategies—more subtle and many-faceted references (and contexts), and since then, the revised relationship of old and new has been defined as a “continuity of interventions over time.” One of the most renowned projects in this vein is David Chipperfield’s renovation of the New Museum in Berlin, a concept which was opposed by a fair number of local experts, but which immediately won the hearts and enthusiasm of the broader public. With the diffusion of clear parameters, the complexity of the project grows. Not uncommonly, the planners face «wicked problems,» (4) and to solve these can, in some cases, mean that contradictory tactics may have to be employed.
(2) cf. Thomas Will, «Grenzübergänge», in: werk, bauen + wohnen, 6 (2003).
(3) The Venice Charter was passed during the Second International Congress of Architects and Specialists of Historic Buildings, end of May 1964.
(4) The term «wicked problem» was coined by Horst W. J. Rittel and Melvin M. Webber in their 1973 article «Dilemmas in General Theory of Planning,» in: Policy Sciences 4, 2 (1973), pp. 155—196.
THE CLINIC AS A TOWN: CLIENIA LITTENHEID
The trickier the problem, the more important the strategies, the wider perspective on the whole, and the processes that can lead to the solution become. In the case of the aforementioned refurbishments of schoolhouses, this «whole,» and thus the main objective of the renovations, lay—along with a general renewal of the structural physics− in the improvement of the use of space. While the renovations discussed so far focus on the immediate context of the single buildings, the renovations and expansion in Littenheid (Canton of Thurgau) expand the meaning of redevelopment to include a whole village. The Clivia Littenheid is a private psychiatric and psychotherapeutic facility that cooperates with several cantons to care for patients of all age groups, from ten-year-olds to people of advanced age. Littenheid is located in an idyllic landscape only a few kilometers southwest of the Wil SG train station, in a valley that curves gracefully through several low hills. From the mid-nineteenth century onwards, the facility, once a school, then a retirement home, and, more recently, a home for asylum seekers, has been continuously re-adapted and expanded. Today, it has assumed the layout of a «clinic town» comprised of several dozen buildings and a generous park. Expansion always followed a pragmatic approach: buildings were erected on demand and integrated into the complex with more or less well-designed architecture. In 2008 the architects created a master plan of all existing structures together with the private owner in order to define their strategic potential and consider possible approaches to an expansion. They addressed questions regarding the architecture of the buildings as well as (at a larger scale) such pertaining to the built-up area and the landscape. Within the heterogeneous group of buildings, there was no possibility for one clear solution; much rather action was required on both spacerelated and organizational levels to improve the village structure.
Fundamental to their master plan was the precise positioning of a so-called «farm building»that was erected in 2010 near one of the
access roads on the site’s southwest periphery. The term «farm building» was chosen in view of the valley’s agricultural tradition and suggests that the new building would be in service to the benefit of the entire clinic. It houses an industrial kitchen that provides some 360 meals three times a day, which are distributed to twenty-four different wards. In line with principles of maximized efficiency and smooth workflow, the kitchen ensures short distances and facilitates eye contact. Signs of a carefully conceived architectonic whole are visible even in the small details: instead of the common chrome appliances typical of industrial kitchens, white anodized aluminum imparts a friendly lightness to the room. A strict functionality doesn’t impede good design, provided the architects put their seasoned expertise to work on behalf of the building.
Like all the secondary, «servant» spaces—such as the stables and workshops—the kitchen has its place on the periphery of the clinic complex. This way, the new building serves as an intermediary between the large buildings in the center of the complex and the surrounding open farmland. Thus, the use of wood as main building material was an obvious choice—a finely structured, white-lacquered veneer around a compact, sharp-edged corpus marks out the building as a special, almost noble trade building. The white paint suggests the cleanliness and purity of the interior and shows the building as a place of integral importance for the entire operation. A concrete plinth accommodates the slightly descending terrain and the different loading heights of delivery vehicles and smaller passenger cars. Two strongly articulated canopy roofs convey an impression of these continuous movements and fluctuations far out beyond the building itself into the built-up, traffic, and landscape zones of the clinic village.
FREESTANDING ADDITION: THE ILGENHALDE SCHOOL FOR SPECIAL NEEDS
The question as to whether a building should be repaired, renovated, or replaced can rarely be answered on the basis of an isolated parameter, since all too often this amounts to a “wicked problem.” During the research conducted for the competition for the partial renovation of Sonderschulheims Ilgenhalde, the comparison of a renovation approach and a new building project showed that a replacement building would in many respects better meet the requirements, while at the same time opening up the ensemble’s—by today’s pedagogical standards—too introverted layout. A cost-benefit analysis also supported this alternative. The concept for the school and home for children with cognitive and physical disabilities was born in the 1960s as the “Association Children’s Home Ilgenhalde” by the Zurich branch of the Caritas. In 1974, and with limited funds, school and home were built as a complex, in line with modern concepts back then, by the Zurich-based architects Mennel & Rüdt. Perceived from the outside as a closed facility, the building was nestled into a kind of artificial landscape, and all of its functions were connected via sheltered passage. The individual buildings branched out from a central axis; the small, row-house-like group residences were located in the south, the main infrastructure was assembled in the center, and the chapel, the gym that featured a therapeutic pool, and the classrooms were all to the north and east.
Opening up the complex and separating residence, therapy, and school facilities reflect the modern understanding of normal day-to-day living. The insertion of a freestanding two-story pavilion to replace the classrooms in the easternmost wing allows the closed form to reach out and the newly designed courtyard to interlock dovetail-like with the landscape. Furthermore, only a new building could meet the demands of today’s academic and diversified therapeutic requirements. The idea of communal living was met with generous spaces for movement and social encounter both indoors and outdoors. These also proved necessary for the sometime large mobility aids some of the children depend on.
All renovations followed the principle of adjusting existing shortcomings at the lowest possible cost and to meet the extensive requirements, which had much changed since the 1970s. The facade, which showed signs of ageing with fissures and even a few leaks, received a new layer of insulation on the outside and, in keeping with the original surface treatment, was roughcast with plaster. The windows were updated with wood-metal frames. The kitchen and laundry were renovated, the gymnasium expanded. The largest intervention was installing a new auditorium in the former chapel with a new stage that was to be accessible from two sides. This most clearly demonstrates that the school’s new requirements were not driven by function alone but as much by the societal changes in ideas of communal living.
CONCRETE UNDERGOING COSMETIC SURGERY: THE WASSERSCHÖPFI HOUSES
The main objective for the extensive measures taken for the renovation of the Wasserschöpfi houses was to preserve the architectural
character of the buildings. The sculpturally modeled exposed-concrete structures, erected by architect Fritz Schwarz in 1968, stand as exponents of Zurich’s local building tradition. The two connected rental properties with their sharply cut corners and their distinct rough surface structure of exposed concrete stand out among the district’s usual four-story plastered row houses with gently sloping pitched roofs. An improvement of the facade’s thermal insulation was required, and simultaneously the variation in apartment sizes was also encreased. Smaller units were combined to create 5.5-room apartments, and in all units the space was opened up to create combined kitchen and living-cum-dining space configurations.
From the beginning of the planning phase in 2000 it was clear to Andreas Galli and Yvonne Rudolf that such an impressive exposed concrete facade should not be allowed to hide behind a new layer of thermal insulation, even if such a «winter coat» has indeed been the most widespread solution for heat loss in buildings since the 1950s. The architects had to bring forward many arguments before all of the players were convinced to take this more arduous, less travelled path of an alternative. Thanks to this solution, however, the strong architectural presence of the exposed concrete facade could be preserved. This willingness to think outside the box is all the more impressive seen that béton brut buildings from the era of the economic boom are generally less in favor with the broader public. Closer investigations of the buildings showed that a replacement of the interior insulation and additional insulation of the basement’s ceiling and the roof would yield the required improvements. In combination with the new windows, whose design, in line with the architects’ credo, were kept as close to the originals as possible, and a reliable ventilation system the task of optimizing the buildings’ energy efficiency was accomplished. The architects once again combined curiosity, experience, and a passion for detail for this project, adapting the interior of the apartments to modern standards, while also underscoring the striking sculptural nature of the exterior’s concrete structures. There were several places where the outermost layer had been damaged by corrosion in the steel reinforcements. Some of these damages were already visible on the surface, others had to be located with a special probe. Contrary to common practice in concrete restoration, the surface was not replicated with a new layer of slurry. Instead, the original concrete structure remains visible. After cleaning the iron rods, the holes were filled with a modeling compound, and the repaired spots on the surface were then treated to look like the pre-existing surface, which showed the typical detailed, rough-sawn structure of the form boards widely used in the 1960s. Adding to the already complex renovation of the concrete facade, another building task involved thinking of building intervention as continuous over time: the garden-facing balconies were expanded by half a meter, which entailed the removal of the exposed concrete balustrades on the longitudinal side. The floor tiling was then expanded, and a new balustrade was added using the same horizontal timber formwork. The enlarged balconies now effortlessly integrate into the context of the buildings.
The examples of the Technical College and the Wasserschöpfi residential buildings clearly illustrate that the renovation of building stock dating from the «second modernism» era (1950—1975) is an extensive task that follows no general guidelines. Instead, assessments must be made case-by-case to determine whether it is sufficient—or appropriate—to simply maintain the existing structure, or whether a more extensive intervention including refurbishment, maybe even conversion is called for to bring it up to modern-day standards and requirements. The sheer number of buildings alone is a critical aspect in itself: the amount of developed and built-up area doubled within a single generation in postwar Switzerland. Today, sustainable methods for managing, maintaining, and developing this mass of building stock have to be found.
LIVING QUALITY ON THE HORIZON: THE DIETIKON–GLANZENBERG HIGH-RISES
Renovating the Glanzenberg high-rises in Dietikon brought an entirely different set of questions to the table from those that arose from maintaining the little architectural gems of Wasserschöpfi. While the efforts on behalf of the latter buildings concerned the preservation of their architectonic character and its adaptation to the modern age, the monumentality of the high-rises in Dietikon—whose presence radiates far out over the Limmat valley—was emphasized further and even symbolically exaggerated. Thus, while the Wasserschöpfi can be seen as a didactic project, Glanzenberg is an urban intervention with the aim to make the high-rises readable as such.
Location was a defining factor in the reinterpretation process: the Glanzenberg high-rises are situated in the Limmat valley, close to important junctions and transportation axes of national significance. Generally speaking, such a location would be considered rather unattractive; and indeed, the image of the residential development in the urban periphery suffered a major blow after the brief economic boom of the 1960s. Slowly, however, opinions on this matter are changing, especially with regard to sustainability issues: high-rise buildings still provide one of the most efficient and space-saving options for urban living. While the structural quality of both Glanzenberg high-rises—the property of a housing cooperative—was outdated and not deemed valuable, the buildings were to be retained for the high floor-area ratio they provided for the plot. Thus, the architects made systematic and careful technical improvements in the renovation of the two thirteen-story structures. The heart of the project, however, is the alteration of the spatial arrangements, accentuated by an entirely new visual presence.
What matters is the architectonic answer to an architectonic question. Principally, this concerns both living quality and urban presence. The former mostly has to do with the interior—in the case of a high-rise, the entrance area on the ground floor and, naturally, the apartment itself. Here, Galli Rudolf Architekten expanded the old balconies into loggias, each measuring some twenty square meters, which run the full width of the apartments. The rest of the floor plan remained untouched, for the most part. Yet the extension of the balconies had an impact on the outer appearance of the structures, which led to an entirely new interpretation of the building’s character. Galli Rudolf Architekten fit the new balconies into the overall sculptural integrity of the buildings, thereby reducing the segmentation, smoothing out the facade. A continuous glass balustrade lends the design a strongly horizontal impulse and, rigidly layered, one over the other, markedly impacts the building’s appearance. The formerly strongly articulated vertical lines are modulated by a cladding of corrugated metal that was specially designed for the purpose. Thus, the buildings’ horizontal and vertical lines are now in harmonious balance. But the two buildings really steal the show with their striking colors, which, as mentioned above, is the reason for their singular radiance. The corrugated metal cladding lights up in a saturated red, while the balcony balustrades appear as bright orange stripes. Black frames around the balustrades and windows separate the two strong colors. They are not color-coordinated to radiate harmony; much more, there is a tension among them that the viewer understands intuitively. And, as is so often the case, the color also carries a message. It’s hard to miss in this case: Look over here; we’re high-rises, and we’re proud of it!
A strong commitment to a cause sometimes runs the risk of being misunderstood as hardheadedness, but this is hardly the case with Galli Rudolf Architekten. Building is a negotiation process, and with renovations and transformations in particular, great tact and sensitivity are required for the interaction among the many players to be productive. Knowing and being aware of the main objective and each individual’s role in achieving it is thus all the more important. The architects’ responsibility is architecture; they must identify and interpret the architectonic potential of an existing structure and find an answer to it. These architects combine curiosity with experience in their work. And governing it all is a keen and critical intelligence that always stands to question, and sometimes reformulate, the context of the task at hand.