Conversion of existing structures is a process that is universal, affecting all types of buildings, whether they are a redundant place of worship or an unused transformer station. Examples include London’s Garden Museum by Dow Jones Architects, which is housed inside a former church, whilst the Tate Modern Gallery by Herzog and de Meuron is located inside the old Thames Bank power station.
However all buildings can be subject to transformation to become something entirely different to what they were before, no matter what their prestige, scale, type or previous use. Historically of course in pre-industrial times conversion was a common and accepted practice which took place both within an urban and rural context.
Therefore conversion is arguably not a new concept as it is clear that historically as social patterns, needs and activity have altered so to do the demands placed upon our buildings to perform new uses and provide a useful and facilitating framework have also changed.
In regards to the present, since the 1970s the percentage of investment in new structures has been falling whilst, at the same time investment in existing buildings has been steadily rising and continues to increase correctly.
However just why is conversion seemingly becoming acceptable as a solution once again? What is certainly apparent is that this is both a rural and urban phenomenon, as most industries are currently subject to an increased programme of rationalization and consolidation, downsizing assets and thus reducing the amount of storage, working and production space. This applies to farms, manufacturing works, offices and even certain types of housing such as the Park Hill estate in Sheffield.
As well as a programme of rationalization, ecological concern has also acted as a catalyst to instigate re-use and recycling of buildings. For example by retrofitting offices or housing, the energy that would be required to demolish and rebuild is conserved. Therefore it is arguable that modification now predominates and indeed could even be proposed as the dominant and most feasible future component of the architectural profession within the current context of rationalization and sustainability concerns
Both of the above describe why we may embrace conversion increasingly as a solution, however they do not elucidate the process by which it went out of favour as a solution in the first instance and why ‘adaptation’ is still perceived as a compromise by the architectural profession. Architects such as Zaha Hadid or Daniel Libeskind still prefer to articulate their buildings as detached sculptural entities, often beginning with a blank canvas and responding to an abstracted concept with a focus on innovation and the avante garde rather than to engage with the complexities that an existing architectural situation presents.
This change in architectural practice towards the detached, self generated entity can be traced from the shift from pre-industrial Europe during the early part of the C19th which proceeded to prompt enormous industrial expansion, which in turn influenced substantial urban, and, to a lesser extent, rural development all of which were constituted largely from new buildings, albeit often in a historical style, but still embracing new technology and, gradually, an increase in scale and capacity regarding programme.
This situation coupled with a lack of perception of historical buildings as valuable artifacts meant that demolition and replacement with new was the established and uncontested approach well into the C20th. The perception of old buildings was not one of potential or a perception informed by their embodiment of the past, but rather as them obstacles and barriers to innovation and the development of a pure architectural solution.
However this preconception has largely abated over the course of the last half of the century with the methodology of conversion itself presenting a unique process which develops from an existing building no longer fulfilling a relevant use or function. A dialectic situation therefore present itself between the existing and the proposed, expressed both through the past and intended activity as well as in differences in aesthetic and visual intentions between what is present and what is envisaged. Therefore engaging and responding to a rich context, whilst a challenging process, could actually therefore serve to facilitate a more complex, multi-layered and interesting architectural solution integrating progression, innovation, responsiveness, appreciation and a resolved dialectic conversation expressed through chronological layers of building change.
However whilst the history concept itself is all very well what about the methodologies that exist that allow architects to facilitate conversion? In regards to this question at first there is a seemingly wide range of current methods and processes, as well as theories, regarding how to engage a conversion of existing structures. However a common link is that is perhaps prevalent is that all examples of conversion elicit the method of considered adaptation and change to some extent. The difference in each instance therefore occurs though in the degree of change, which is in turn informed by the activity or function that needs to be contained with the existing.
Carlo Scarpas architectural approach, particularly at Castelvecchio in Verona (1956-1964) has, until recently, been considered to present an exemplar in creative building re-use. Here contrasting, but fully integrated additions and adaptations predominate and are still considered to be suitable in their execution and narrative. However upon closer scrutiny Scarpa’s approach can be seen simply layering contrasting additions onto the old and relies primarily on an interpretation a building as an archeological site. This explains why his work is focused in richly layered situations such as Venice and Verona where the existing presents an interesting and multi-layered condition with which to work. Furthermore the focus is on cultural buildings such as museums, galleries and institutes where a degree of self-indulgence on the architect’s behalf is possible, for example it took Scapra from 191956-1964 to complete the Castelvecchio museum. It is doubtful therefore that his considered approach focused on meticulous, exaggerated tectonic layering would be applicable within a more pragmatic and constrained, commercial situation.
The problem lies in the use of the description ‘exemplar’, as its use suggests that whilst outstanding the approach has not yet widely applicable to the main stream. Alternatively perhaps it highlights that there can be no overall methodology and that the context was ‘right’ for Scarpa to engage in the way he did, whilst currently within a changed economic, political context a different architects approach would entirely different. This is beside the obvious differences in the existing buildings that present themselves in each context, each entirely different in the way they reflect their milieu.
USE
Perhaps the principle challenge for architects developing conversion schemes is the shift in the established relation between an existing building and the use for which it was developed originally. Buildings reflect and embody use and as such to place a new use within an existing building can often seem like trying to wear a piece of clothing that doesn’t quite fit. The existing building envelope still ‘fits’ a previous context.
The easy solution therefore would be a demolition and rebuild, however as we have seen pragmatically this is an unsustainable and indeed one-dimensional solution denying an opportunity for a synthesis between a dialectic situation of past and present layers of history and construction. Quite often it is how the existing building is perceived that informs the programme of adaptation. Everything from a country house to a warehouse can be converted. What determines the extremity however is often dictated by where it is located on both a historically valuable and indeed commercially viable scale.
At one end of the scale historic buildings often have to be coupled with a suitable For instance castles become museums, palaces art convert to art galleries, old town halls transform into concert halls and churches adapt into libraries. The programme is cultural rather than commercial and as such the devised uses are usually sympathetic to the existing and relatively straightforward to articulate in the spaces as they are presented. As a result the extent of adaptation is minimal and can be articulated to a high standard, due to the lack of a commercial, money-making bias.
On the opposite end of the spectrum however industrial buildings, housing, offices, old hospitals or power stations usually present a still viable commercial commodity. These projects are not often perceived to be as historically valuable as the examples indicated above and as such more extreme changes in use take place and as such more extensive, wide ranging alterations and additions. Therefore complete change is often possible, for example offices into housing, industrial buildings into offices or power stations into shopping malls.
A polarization is therefore evident which is fundamentally informed by and based upon perception, which ultimately results in classification of building type; broadly speaking either commercial or cultural. Consequently the potential to accommodate changes in function is dictated by this perception and so subsequently the physical intervention and conversion will eventually reflect the extent to which the change is exercised.
A CONVERSION SPECTRUM
Of course once the extent of conversion is established the methodology is also open to interpretation and suggestion. In reality there are no established design principles and arguably nor should there be, if the architectural solution is to be integrated and responsive to a particular existing situation. However guidance is published by organizations such as SPAB, English Heritage, ICOMOS and UNESCO which is concerned with the protection and conservation of historic places and landscapes.
Ultimately however the combination between old structures and their previously accommodated uses and proposed activity requires a specific solution, which depends upon both the building as object and the tasks contained. Idealistically the concept of the genius loci is therefore re-enlisted with each unique situation prompting an inimitable dialectic conversation and solution.
The spectrum of design within existing structures ranges from the recreation of destroyed or ruined structures (restoration) to complete demolition and redesign. In between these polarized approaches sits both the conservation and arrest of decay of what exists and the application of contrasting additions.
The extent of these alterations depends however not upon the guidance prescribed by an imperatives but rather upon the interpretation of the individual situation by the architect. When engaging with existing buildings a dialogue is being established between the existing and proposed, not an independent and detached gesture. As such the range of approaches is endless in the variety of possible extents of application. It is virtually therefore impossible to prescribe a series of standard design approaches as, because the process is reactive, the result of each engagement will differ based upon a broad of factors.
Despite this however it is possible to identity a spectrum of adaptation ranging in intensity from complete restoration to complete integration of the old and new to create something that presents an entirely new entity.
PRESERVING THE OLD
Many conversion projects still hinge around the concept of preservation and protection of an existing buildings as heritage structures. Here the historic original is the central consideration and as such a programme of consolidation and protection ensues. This in itself can range from complete restoration (Frauenkirche Dresden restored 1994-2005) to preservation and consolidation (St Paul’s Cathedral – Purcell Miller Tritton) and finally light repairs; however this only addresses the existing structure as a physical envelope and not as the potential accommodator of a new function. Therefore it is often the case that in buildings perceived and thus classified as historic, such as churches, palaces, castles for example have to accommodate a new activity that is compatible with the buildings in their present configuration. This a prevailing aspiration held by certain action organisations such as the Georgian Group where the ideal is to use Georgian buildings for their original purpose, for example large country houses, even if this is entirely impractical within the current social, economical or political context.
Interiors and exteriors are preserved and the, lets say, palace, is opened to public in an altered state, but not usually visibly presenting change. The focus therefore in this instance is either upon authenticity and restraint or alternatively recreating an historical, hyper realistic ambience. Both approaches are indulgent in that they often result in the building becoming detached from current reality, but also relevant in that it is appreciated as a preserved relic in itself serving a current, commercial viability as a cultural attraction.
LAYERING ONTO THE EXISTING
Conversion in this middle ground explores the juxtaposition and integration of existing and applied layers. The pursuit of the homogenous whole that assimilation or restoration strives to attain is replaced with a multi-layered approach, which forms a new whole through the interaction and engagement of the singular parts. A difference is created between the new addition and the original, which are distinct but combined. The extent of these interventions depends, of course, upon the nature of the situation and the architect’s interpretation. A dialectic between the iconic, functional and aesthetic elements of the existing and proposed are thus explored and articulated.
The work of Carlo Scarpa perhaps serves as the model for this approach in converting architecture. The Castelvecchio museum for example illustrates this tectonic and iconographic, collage-like layering where Scarpa peels back and plays with layers of history both in the existing and the new additions emphasisng and celebrating difference. This strategy of difference has been much employed over the last half century within architecture as a solution regarding how to often place new functions within existing structures, which are then often restored and consolidated themselves. This approach, whilst in some instances proving interesting and multi-layered solutions can often present a situation of detachment, where the new layer dominates both aesthetically and functionally. Consequently this can create a sense of imbalance where the old is relegated behind the existing as a conserved relic or allowed to decay into irrelevance.
FUSION OF OLD AND NEW
Interestingly as a trend has emerged recently within architecture to convert and alter existing ‘mass-produced’ or ‘everyday’ buildings the methods that may apply to protected and valued heritage structures are not applicable and as such have been superseded by a new approach of integration. Haworth Tompkins architects perhaps illustrate this approach to the existing as fully adaptable and changeable material most efficiently. Their conversions at Aldeburgh Music Centre 2009 or at the Coventry Herbert Gallery 2005 focus upon creating a new entity from both the existing and new that is seamless and whole. Tectonic connections here are less emphasized and unlike the work of Scarpa, the new appropriates the old and the old willingly accommodates the new; thus a homogenous total is created. This concept of the new entity that is responsive to the specific needs of a particular context, fully integrating an existing building. The old is therefore not restored to imitate a historical authenticity or left to decay, but coherently forms part of a consolidated new whole through fully integrated additions.
