REUSE Author: Kimmo Lintula, K2S Architects Ltd., professor Aalto-University
Helsinki Olympic Stadium Revitalized
Introduction Helsinki Olympic Stadium is a national monument, a crown jewel of functionalistic reinforced concrete architecture in Finland. Since its inauguration the stadium presented first as the winning competition entry “1500” by architects Yrjö Lindegren and Toivo Jäntti has undergone several changes and extensions. These supplementary parts constructed in latter decades created valuable history of the relation between use and architecture in built form. It also has a significant symbolic value in the Finnish society; a tool to gain a nation international fame by combining forefront sports and architecture. Since it internationally well known and it has been researched and published widely I will point out features that either led to the current project presented as case study or ones that were to be evaluated during design process. Helsinki Olympic Stadium in its 30`s appearance met the criteria of utilitarian architecture in almost every levels; forms of the building, dimensioning of the spaces, choices of the materials and building techniques. The result of an open architectural competition, was built into a composition of vertical tower ( 70 meters tall) and horizontal stands. It had a canopy on its western main stand and a building beneath connected with a west wing museum. The interiors of the building were painted with earthly colors like chalk, green and gray. The concrete was cast in-situ and all surfaces of the construction were rendered and painted white excluding the stand A canopy which had a painted cast mold board surface. Benches were constructed out of linear timber bars and treated with linseed oil. The stands and the facades behind have been constantly evolving with capacity and appearance when stadium has been prepared for coming large scale events; first the 30s` (20 000) then the streamlined temporary wooden stands for the Summer Olympics 1940 (50 000), then the horizontally meandering mix of temporary timber and permanent concrete construction with vertical wooden claddings to finally host the Summer Olympic Games in 1952 (70 000). After the Olympics major changes were the new premises under the southern stand and northern stand a (1953-1961, Toivo Jäntti), a series of changes in interiors (1953-1961, Toivo Jäntti), the renovation and modernization of the stadium 1990-94 (Markku Aalto), where the cast-in-situ concrete structures were replaced by prefabricated concrete elements in the stands of the south, east and west, and the seats got carved backrest. 2003 as a result of an open international architectural competition stadium got a a permanent cover in the form of steel construction clad with wood on the eastern stand (Kimmo Lintula, Niko Sirola, Mikko Summanen). In 2010 new public facilities were built on the ground floor as well as the field went on a refurbishment in order to accomodate official IAAF track & field conditions as well as UEFA`s requirements of the dimensions of the field with capacity of 39 000 spectators (K2S Architects). The procedure to have building listed was proceeding at the same time and the new canopy became also part of the listed entirety in 2006. Heritage and lasting legacy Since Olympic Games it has been almost 70 years meaning that the building has had to adopt for several usage different from for what it had been originally designed for. Despite the remained symbolic value this has created a blurred combination of scattered functions and built add ons prevailing the original simplicity and pureness of the Helsinki Olympic Stadium.
The core functions themselves; sports and events; have changed along with their functional requirements. A series of workshops were organized to find out the needs of the core needs of the stadium activities in the future context. Major stakeholders being national and international sport organizations, event organizers, agencies taking care of tourism and travel, athletes, artists, security and authorities as well. This exercise of defining “ the evolving functionality” was executed in six stages evolving each round more than 80 key groups. Historical building surveys (Mona Schalin) were supplemented with a document “building protection illustrated” defining the “physical heritage”. We created this document to understand written definitions in relation to built reality and further more to identify potential areas to accommodate the future functional needs. A series of technical surveys were done on the whole building for the evaluation of the physical condition of the stadium. Theoretical framework Discussions led in to a mutual understanding between the project partners on theoretical framework; the best way to preserve a building is to keep it in use. Helsinki Olympic Stadium remaining the number one national sport and multipurpose arena to be used daily by citizens and visitors was set as the goal. We concluded this in an assessment plan. Interventions were found justified and with them future goals could be reached. Extending the plot, refitting the tracks and playing field, covering the open stands, replacing the seats, reorganizing the flows and logistics, repairing the structures and facades were to be further motivated and analyzed by architectural design in the scope of preserving the historical and architectural values. Revitalizing The key question for us as architects was to understand how could we turn this historical stadium in to future arena and to maintain the heritage? We approached this question by using analytical methodologies and suggesting functional needs as key components of the listing features. To understand the physical effects of needed interventions a series of experiments were executed. This was to figure out ways of construction and to decide the relation between restoration, reconstruction and conservation. Approach We formed a interdisciplinary project group: K2S and NRT Architects supported with Wessel de Jonge and White architects. A tool set of methodological analyses was applied (with great input by Wessel de Jonge) resulting in the four following architectural approaches: First being preservation of 1930`s facades, interiors and canopy with restorational repairs. Secondly areas with new interventions and new additions: new canopies, new vomitories for the stands, reinforced concrete structures, unobstructed people flow routes, replacement of the stand C, new seats for all stands, new vertical connections in the building A and alterations for the ground floor premises in the building A. Thirdly modificative reconstruction of late 50`s facades with cladded timber facades and outdoor areas and the fence. Fourth being the new underground premises for logistics and multipurpose use in the western and northern parts and a new northern “square”.
Method Based on the Historic Building Surveys transformation guidelines were formulated. These were then used as a frame of reference and compared with proposed interventions based on the future functional needs. This was to find out the most determent features for the architecture-historical value of the building or it`s
parts. This analytical approach enabled us as a design team to discuss the interpretations with heritage authorities and other stakeholders to anticipate the needed transformations or re-designs. The elements considered ( case by case) were: 1. Urbanistic-historical value - Role of the building part in the whole ensemble and the way it is anchored in the urban and natural setting 2. Culture-historical value - Role of the building part in the representation of the whole ensemble in the cultural history or architecture and art and as a historical venue for sports and culture. 3. Typology - Role of the building part in the whole ensemble representing building typology of it`s era or as a functional structure related to logistics 4. Exterior - Role of the building part in the whole ensemble representing architecture-historical and material qualities 5. Interior - Role of the building part in the whole ensemble representing architecture-historical and material qualities 6. Service systems - The historical value of particular service system representing architecture-historical and material qualities
The “transformation potency” of the suggestions was defined according to three categories: A. Limited transformation potency B. High transformation potency C. Mixed transformation potency.
Case-study The following examples illustrate how the created methodology was used on the context based approaches. Basically the first thing to check by sketches was to study whether future functional needs could be fulfilled by just adjusting the way spaces are used or people flows are directed. This was identified as a design goal of “make most of what you got”. When needed the next step was to figure out interventions and analyze them through created method. At the same time these interventions were thoroughly studied in order to fulfill another design goal; “solve multiple problems with one architectural gesture”. This was then repeated till the set goal met the evaluated criteria from preservation point of view.
The concrete canopy of the original 1930`s building stand A - Preservation with concervation Building A with it`s canopy is a central part of the ensemble recognized as the national venue for sports. This grand stand is marked in the urban environment by tower and a western façade organized in programmatic composition representing almost “ classical” division of relatively uncommunicative base for
services on top of which a gallery opens up to landscape completed with a second floor premises with large steel windows. All this is organized in structural system of 3x3 meters under the back edge of the covered stand. Other than added glass windshields on the gallery façade in the 90`s this building entity`s western facade stands almost intact in the 30`s architectural and material expression. On the inside (stadium bowl) the Grand Stand is marked by white and board textured concrete canopy on top of the continuous curved ranks blending into utilitarian architectural character of the bowl. The canopy and it`s material expression had been only affected by suspended commentator booths in the 90`s and it was considered to have a limited transformation potential. The roofing out of bitumen had been redone several times and was valued to have high transformation potency. The technical surveys had shown that the concrete of the canopy was almost fully carbonized and it was structurally at the far end of it`s capacity. The functional needs concerning the use of the bowl and the field were merely about replacing all technical installations including lighting, loudspeaker and operator systems. From technical point of view four options for repair were considered: re-inforcing the existing concrete with 50 mm layer of sprayed concrete ( method used in 30 mm thickness to reinforce the tower and concrete structures in the 90`s), demolish and rebuild the canopy out of concrete, demolish and rebuild it out of steel structure and rendered cladding and last highly debated restorational repair with minimum amount of interfering the remaining material. Leading experts and academics were invited to participate and after a series of round table discussions based on the analyzes and research on this specific case it was decided that the restorative option was the most sensible approach. It was also the only of the options that full filled the guidelines of the transformation potency. After the decision to move on with this approach we did together with stakeholders excursions around European stadiums and visited the sanitarium in Zonnenstraale. There had been similar issues to be dealt with. The method used there for reinforcing concrete beams with carbon fibre clued on top of them turned out to be the saviour for the A-stand canopy in Helsinki Olympic Stadium. The roofing was taken off and reconstructed after the beams had been reinforced. Reconstruction was crucial with even on the details of ventilation and sheet metal work since the conditions in side the cavity of the canopy were found to be optimal and thus crucial in keeping the concrete chemical remission. The under side was very lightly vapour blasted, the rusted steel was cleaned and painted with rust-inhibiting coating. This way the texture of the original sheathing remained visible and the essential quality could be kept. A new railing system for the needed fixtures was then designed based on the research of the original drawings and old photographs of the canopy. This visually separated the fittings from the concrete geometry and kept the physical interventions in minimum. Utilitarian expression was set as an architectural approach for the new premises in order to relate to material and structural expression of the stadium complex. Rough exposed cast in situ concrete, thick rubber mat, steel and timber. The new multipurpose halls were cladded in tinted white timber as a “mirror image” of the white painted board marked concrete textures in the existing stadium premises. The longitudinal corridor connecting them has a repetitive character formed by continuous rhythm of concrete columns framing rectangular timber niches referring to classical western gallery façade. Three of these open up towards the Building A as light wells to give also a sense of orientation. The color palette was kept in monochrome tones with only wood as a distinctive color in underground premises.
Preserved areas with new interventions and new additions: The bowl The main challenge for the bowl was to find an architectural solution for placing an IAAF standard track as a field. Also stands were set to be covered, new seats to be designed, and new vomitories to be placed. The stand was defined by having a mixed transformation potency since the materialization of the stands and the wooden benches had been changed in the 1990`s. Also there had been made changes on the northern and southern corners of the main stand. Needed modifications went further but were justified by reasonable needs to do with the original quality of the stadium; to enable its core functions is to secure its future vitality. At the same time the steel railings and original metal sheet works were more or less intact.
These were to be preserved and reconstructed when needed. The timber cladding of the presidential balcony was to be concerved. Stand C As the requirements for the international sport events have changed a lot during the time and the historic stadium in its state at the time did not full fill these criteria interventions enabling its usage as sport venue. To fit the IAAF standard track some of the original needed to affected. Since the field sits in between stand A and C it needed to be either one. A being the covered main stand and conceptually and architecturally regarded more important than stand C it was proposed that intervention would take place in the area of C- stand. This was seen as a chance to solve the disadvantages of the stand C; a new stand with proper sight lines could be built providing accommodation with high quality seating for disabled spectators and VIP`s. Underneath a series of service spaces could be built for the spectators. New vomitories Vomitories were placed at the back of the bowl in between the structures. Also two of the 1950`s staircase`s were extended to land on the back rows of the stands. The new concrete stairs were plastered to blend in but they have a distinctive folding expression on the under side. The intermediate landings are fitted as balconies following the rhythm and scale of the façade. At Grand Stand in Building A three new vomitories were proposed in order to accommodate seating for disabled and to be able to access the second floor premises used as a “back boxes” during the event. This was found to be in conflict with the transformation guidelines but was seen as a benefit for proper usage of the stadium in the future. Thus the conflicting intervention was acceptable while making sure that the with the detailing the effect on material qualities was kept minimal. New canopy Since 2005 the new eastern stand canopy had been part of the listed building entity. To cover the southern and northern stand had been one of the key targets. Aware that this would have a great effect on the image of the entire stadium architectural approaches were studied carefully in advance. Looking at the criteria used to determine the transformation potency it was clear that any kind of “third” element would be in great conflict. The idea then was to continue the existing canopy and change its upper form in order to enable higher steel structure resulting in longer spans and fewer columns. This was considered a major benefit for the spectator accommodation and sight lines. Structural analyses showed that the steel construction should be free floating (because of the large spans and lateral movement) and be connected to the existing concrete structure by using sliding bearings. This led into need of reinforcing the concrete structures meaning also that the fittings of the 1950`s façade needed to be redesigned and built. The canopy itself was designed as timber cladded double curved form with thin as possible edges integrating all the technical installations. This was to fit the architectural scale of the existing canopy at stand A and to mark a clear presence of the new element in the stadium bowl. Seats In preservation terms the most problematic question was the seats to be replaced. Visually the bowl is made up from continuous ring of stepped stands with horizontal timber tiers of seats. All though the wooden benches had been replaced in material and the back rests had been added the strong visual image followed the original idea of play of the horizontal utilitarian stands and vertical tower seen from the bowl. This resulted with mixed transformation potency with the idea of having to be preserved but possibility of discussing interventions if original features could be retained. From the usage side the temporary exception allowing football being played in a venue with no individual seats had come to its end. There was also demand from the stakeholder to reduce the maintenance costs and have better comfort value for spectators. Safety became an issue as well since the fixed benches meant that the circulation and the egress were not sufficient. Since the seats had such a major role in representation of monumentality and materiality of the culture
historical icon no products available in the market were considered suitable. We created an approach of reconstructing the image of horizontal tires with materialized texture. In order to allow maximum ways of usage in the future a fixing rail was introduced. This allowed to change the lay out of the stands with individual seats and removable tables depending on the events needs. We sketched a seat consisting of 2x2” strips placed horizontally with a gap between. Since the seat needed to fold when not used we formed its` back rest as a continuous line. To meet the criteria of maximum comfort the ergonomy was created by “carving out” the desired form. The setting combined in an architectural gesture historical values with future usage. Along the design materialization was researched thoroughly since it had remained intact regardless maintenance works. Durable way of using wood in individual seat exposed to weather with a lot of movement and stressing lateral forces was the question to be answered. It needed to be out of timber no question but could there be another way of looking into it? Door was opened also for wooden composite. A outdoor laboratory was established on top of the Building A canopy. Three years of testing and development work on details a seat of wooden composite was created. By this multiple challenges could be resolved: visual role of the seats as part of the monument, materialization, spectators safety and comfort, maintenance and future usage.
Alterations for the ground floor premises and new vertical connections in the building A The clarity of functionally organized Building A directing the flows during the events had been blurred since 1970`s. We wanted to retain the presence of the geometric structure of the building. The vertical rhythm of rigid structure in contrast to horizontal longitudinal movement in the building was also to be rediscovered. By organizing the service spaces as monoliths in between the multipurpose rooms with large openings to the central corridor we were able to have daylight which is filtered through the horizontal window strips from 1930`s present in the interior. This was considered possible by taking into account the original design principles since the ground floor lay outs, partition walls and materials had been largely changed. The proposed design also emphasized some the original features that had stood time intact. The multipurpose rooms on the ground floor level of building A are used for sports, meetings but also as a hospitality area during the events. Since there was no way of having additional space built connected to building A gallery on the first floor the only way to deal with the number of people to be served and avoid the congestion on the gallery is to divide them into different floors. This was seen possible with efficiently controlled flows but at the same time it was recognized that interventions in form of vertical shortcuts were unavoidable. The gallery as it was had a limited transformation potency. As the functional need for solving the shortcuts was to benefit in several ways the we as a design team researched further the different phases of the gallery. From the old photographs one could tell that the original concrete service counters had been demolished. Since there needed to be service (kiosks from the 1990`s were turned into toilets) organized in the gallery we came up with the idea of rebuilding the counters. Then there was an idea of modifying two of these into a staircase connecting gallery with ground floor premises. They could be fitted so that they retain the essential qualities of the ground floor corridor as well as in the gallery level they became part of the strategy to restore the original lay out of hospitality counters. While being a strong intervention it provided not only described solutions for functional requirements but it helped to avoid complicated in more visible parts of the building. A new northern entrance was created to have an equivalent entrance to the grand stand as the southern one. This followed the original urban idea by Lindegren Jäntti of the entrance to the stadium by south-north axis.
New premises The stadium sits in between the urban built landscape and the ever green pine forest on gently sloping western rigde of a hill. Since late 1950`s only a limited amount of urban interventions (extensions of the stadium building) have been built. The Stadium complex still had a intact and strong relationship with the surrounding landscape. It had also maintained iconic status in Finnish architectural history and as part of the collective memory of the Finnish nation. This resulted in limited transformation potency meaning that no new building volumes should appear in front of the existing stadium. The functions that needed to be connected and could not easily be fitted in the existing building were to be placed next to it but underground. This meant that the relationship of the building with it`s surroundings was kept intact and only the vertical connections needed to be realized inside of the existing building frame minimizing the interventions. This strategy also meant that there were no restrictions concerning the forms and lay-outs of the new needed spaces. We placed a series of multipurpose halls with dressing rooms in western part on top of which the outdoor areas were arranged following the visual ideas of the original 1930`s lay out. This promotes the monumentality of West and South facades for the visitors arriving to the stadium or to the museum. In the north were placed the all logistics with a vehicle entrance. The north side was considered to have mixed transformation potency since there had been many interventions executed during decades resulting in poor usage and architectural quality. A new northern square framed by a curvy service canopy was designed on top of the logistic area. It followed the lines and themes drawn on the original site plan. Although we were not able to be sure what those lines had meant they clearly indicated an architectural intention of clearly defined place. Original ticket booths were restored and next to them a new northern gate was opened to the stadium bowl in order to ensure unobstructed flow of logistics while preparing the events. This also retained the spatial and cultural value of the eastern marathon gate as the seremonial element. These two areas were connected by a tunnel following the curves of the running tracks above. This “mirror stadium” allowed the outdoor galleries to served during the events without obstructing free people flows.
Results and Conclusion Helsinki is a good example of lasting legacy in real. The unique and authentic Olympic architecture of the modern movement still used proves it to resilient. It is also part of our cultural heritage. I have shown you a case study on the values of the heritage in the context of future demands and needs. It is presentation of research by design where decisions were made by exposing utilitarian needs to cultural values. Each solution has undergone several stages of evaluations before being realized in built (or demolished) form. This case study also revealed the technical challenges that modern movement architecture brought to future horizons has to meet. As an example of functionalistic architecture the architectural appearance and material qualities of Helsinki Olympic Stadium are presentations of its functional qualities. Thus the heritage value is not only defined by physical elements but as well by its capability of being used as the arena for top sports. It needs to evolve to stay alive. Simple forms and simple expression have represented the ideas behind the architecture seen in Helsinki Olympic Stadium. We believed these principles were strong enough to phase the challenges of the evolving functionalism. The stadium sits there on a hill still – ready to conquer future horizons with the heritage of the past.