ISUP papers

I love to construct buildings, to design themin relation to their physical surroundings, the streets and squares they form, to think of them as part of the history of a place and to contemplate their expected and unexpected uses. I love to transform abstract thoughts and immediate observations into a physical shape, to think of buildings in terms of materials and techniques, and the knowledge and craftmanship it takes to construct an object of everyday use that will stand the test of time. I work on buildings in different contexts: in the centre of historic cities, in shopping streets, on a university campus, in an average urban street or a small village. And by the act of constructing, we change those places, we change their physical surroundings and introduce new inhabitants and users to them. Density in terms of floor-to-area ratio, apartments-to-hectare or inhabitants per square kilometre has little meaning for me. But when its increase or decrease is discussed in terms of economic, social, environmental or political determinants, density becomes meaningful. I might even argue that the increasing densification of floor surface and programmes is the driving force of most of the building projects that we are commissioned to design. Contemplating densification starts with a place as we find it, in terms of its landscape, urban spaces and buildings, but also the everyday interactions between inhabitants and users that have developed over time. Often there are delicate balances. Changing the density and altering these balances inevitably requires reflecting on the notion of continuity and transformation in relation to the place and the people that inhabit it.

Adaptive reuse of the former Vroom & Dreesmann department store, Amsterdam

Densification is often associated with demolition and replacement. This association is the result of a somewhat remarkable split that occurred in twentieth-century architecture, a side effect of modernity that left monumental buildings to conservationists to be preserved and put on display as testimony of our collective history, while what was deemed not worth preserving was to be demolished and replaced by contemporary, better performing buildings at a higher density to accommodate urban growth. This was ‘real architecture’, as taught to us in school. This attitude, as I later learned, is in sharp contrast with the work of many great architects who engaged in extending and transforming existing buildings, and by doing so delivered some of their finest works: the Gothenburg City Hall by Asplund, the many houses by Lutyens in England and postwar works by Döllgast and Wiedermann in Munich have become important points of reference for me. As much of our present urban fabric was constructed in the twentieth century, we simply cannot continue with this ‘demolition-replacement’ mode of densification; the existing building stock is simply too large and valuable and it is fundamentally unsustainable, as well as culturally, socially, economically and politically undesirable to do away with it. Repurposing existing buildings in the process of densifying the urban fabric is a crucial challenge for architects of our generation. The development of my own practice testifies to this evolution: we started out with the construction of new housing in the demolish-and-replace tradition, but today more than half of our work involves the adaptive reuse of existing buildings. These are not only housing projects, but also hotels, retail and offices, museums, civic buildings, schools and town halls.

What has surprised me most in working on these existing buildings is not just their capacity for transformation, but their ability to transform, in turn, their envisaged programme and use. Existing buildings exert a certain resistance. Densification does not only mean stripping back a building and extending it, it also means intensifying existing uses and introducing new ones. These projects are about finding the delicate balance between the ability of an existing structure to adapt and its inherent resistance to new uses. Buildings are often capable of absorbing changes, thanks to their generous dimensions and neutral structures, but it is equally true that new programmes and planned uses must adapt to their unique features and history. These peculiarities lend a certain unpredictable flavour to a project. Working on these buildings calls for the art of improvisation in architecture. Admired in music and theatre, it is a peculiar part of our profession that, in times of BIM, risk management and lean planning, we are losing sight of. But it is an essential virtue when it comes to working on existing buildings, up to the moment construction starts, since you never know exactly what you will find once you start stripping it.

Royal Netherlands Academy of Arts and Sciences, Trippenhuis

In the reuse and extension of existing buildings and the resulting densification of the urban fabric, the thickness of the older facades has proven to be particularly valuable. The dimensions of these facades, their relief, and the small thresholds embedded within them allow a degree of mediation between the new and intensified use of a building and the public realm it partially constitutes. These facades give a necessary ‘depth’ to the dimensions of the public realm, and often act as welcome buffers in the ongoing process of transformation, ensuring continuity in the densification process of a place. Densification means introducing new programmes and new inhabitants to a place and, as part of this, upgrading existing buildings to contemporary standards of sustainability and comfort. Such interventions include the reinforcement of loadbearing elements, the upgrading of the thermal performance of facades and the improvement of fire safety and acoustic performance, as well as the installation of new equipment to guarantee ventilation, climate control, electricity and digital accessibility. While each of the interventions designed to meet contemporary standards of comfort have a raison d’être, the result of the accumulation of all these demands in a new or existing building leaves us with a stunning increase in the densification of construction itself. Solving the spatial puzzle required to integrate thicker insulation, extensive installations and a variety of performance-enhancing interventions often proves to be decisive in the design. In contemporary buildings installations have grown into a world of their own, frequently accounting for half of the construction budget. I sometimes sense the weird moment in the design process when installations are no longer there to support the buildings, and the buildings themselves become mere shells for the service installations required to facilitate the envisaged use. In sharp contrast to the immense densification of buildings stands the almost diminishing physical presence of facades in contemporary construction. This is well illustrated by the development of the brick facade in the past century – a widespread historical feature of north European cities. From a 20- to 30 cm-thick cladding at the beginning of the twentieth century, with all the inherent possibilities of relief and expressions in bonding that characterise the architecture of the time, it has developed in recent years into a 3cm ceramic strip glued on insulation. Stripped of any sense of gravity and density, these diminishing facades constitute a paradox in the ongoing densification of our cities.

Office, Mathon, Graubunden

The most tangible outcome of the densification of our cities is their increased proximity. This is a direct physical consequence: we simply build closer together and therefore live closer together. Buildings are extended, intensified and new and old buildings are built closer together. The inhabitants of a place are confronted with new occupants and users, with new programmes and at each step of this ongoing process, we have to re-establish the balance between the existing and the new, between what was and the shifting borders of the private, collective and public realms that make up our daily lives. The facades of existing and new buildings mediate between continuity and transformation. As architects we can bring a certain comfort to this increase in proximity. And yet, the facade that plays such an important role in the mediation of this process is dissolving, reduced to a mere veneer. How can we possibly mediate the proximity of so many with such minimal thickness? In many new buildings I miss the thickness of the facades that grace our older buildings – not the thick fortress walls that keep those on the outside from entering, but the soft borders that ease everyday transitions between the old and the new in a rapidly densifying and diversifying society.

SUD apartment building, Amsterdam

The depth and density of the facades is important in our work. They bring out the material qualities and the haptic and sensory experience I enjoy so much in architecture in our digital times, but they also provide a canvas on which we write the story of continuity and transformation. Notions of palimpsest, the rewriting of a text over another on the same surface, and genius loci, the spirit of a place, prove valuable in exploring the complex layered history of a place and framing its essence. A meaningful distance between inside and outside, the overall proportions, the choice of materials and small gestures allow a building to respond and resonate with its environment. It simply helps a building, with new programmes and inhabitants and an identity of its own, to fit in. The challenges are not unlike the personal challenges confronted by newcomers: how do I adapt without losing my personal identity? How do I interact? How do I position myself within a pre-existing situation? Architecture has the capacity to deliver a meaningful balance between presence and absence, between foreground and background, between the depth of texture and the gleam of reflection, between the visual and the haptic, the flow of everyday life and the timeless structures that shape our cities and societies. Amidst the ongoing densification and diversification of our cities, the question to be addressed in architecture is perhaps not about the degree of density, but more precisely about how we construct meaningful proximity.