INTRODUCTION We live in times where demolishing a building is easier than restoring and placing a value on it. There is a hidden history in the objects and buildings that is necessary to discover or rediscover. When we work with an existing structure we cannot avoid to make a continuous reading of the elements and the background of the original building work. For us this is the searching of a riddle and having the opportunity to figure it out. We like to think that this riddle can be solved, in the words of Pierre Bourdien, as a “sense of play” and it does not depend necessarily on the designers but on the passage of time and wear and on the social agents involved. We believe that this fact alone deserves to be unveiled, and in this case maybe it was our only premise upon design. We think restoring the Diego Portales building (or what is left of it) is a gift. We saw a challenge but also a golden opportunity of working with all this historical burden that in our opinion could not be wasted on short-term political desires specially on some atavistic declaration of “clean slate” of the architect on duty.
HISTORICAL CONTEXT This building, like no other, has been an important actor in our recent history characterized by an ideological and political polarization, and by the social division. It was erected as a symbol of “the new man” during the government of president Salvador Allende and after the coupe became the seat of government of General Pinochet’s regime, embodying the “Center of Power” So, in the last three decades, from the perspective of the city, this building has been surrounded by railings, closed and guarded by security requirements required by the government and after by the Ministry of Defence of four administrations. For this reason the building has not been regarded as a beloved object and has a biography a kind of “bipolar” The original structure was designed and built in record time. As a strategy, a large deck of colossal dimensions was conceived by the architects and subsequently installed underneath the premises defined by the regulations during the construction of the building. From the beginning the urban impact caused was deep since a large building, on one side, is perching on the sidewalk of the main avenue and on the other side is invading a residential zone with little french style buildings On March 5, 2006 a fire started in the east sector of the building destroying completely the Great Hall of plenary sessions with a capacity of 2,000 people. This leads the government to make a decision regarding its future and calls for an international architecture competition in which our project won the first place among 55 proposals. URBAN PROPOSAL The way of how to face the problem, from an urban viewpoint, is not from the building itself but from its environment, that is, the piece of city that surround it and which has not been connected with for many years. Therefore the first thing that appeal to us were the block’s buildings and public spaces. Our design strategy was to determine its role in the city. The building just adapted itself to an urban design that, in our view, re-establishes the connection of the place with its context becoming on the exact opposite of what is today. Here the words of Jean Nouvel make all the sense: "A contemporary building being part of a site or an existing project is successful when is able to enhance its surroundings and at the same time being enhanced by them” Our proposal, from a technical and expressive perspective, is simple since it adopts the architectural ideas and qualities of the original project and that is interpreted in a contemporary way for the construction of a new group of premises. Four main ideas stood out but we fused them into a single concept of “transparency”. These are: the openness towards the city and its urban relation by setting a large deck and loose volumes underneath; the built of new public spaces; the opening of the building to the community by including a community program; legitimate the project by incorporating as many social agents to give shape to a new benchmark for the city. This proposal seeks to segment this large urban outline in three small-scale buildings being able to articulate a set of new public spaces.
OPENNESS AND TRANSPARENCY We choose to reveal and display part of the varied life inside the building to the exterior and somehow show the activities and their protagonists and share them with the passer- by. The building plays an important role in the spreading of what is going on inside. Furthermore, from the urban perspective, is a gift to the city providing it with new public roof covered and equipped spaces. A building used for cultural and artistic activities should always have different degrees of transparency and being shared not only with their direct users but also with the community in general. In a context where showing everything is impossible (since inside the building many halls are used for entertainment) the challenge is to know what to show and how. This means the different degrees of transparency are displayed through a façade system that gradually goes from the wide open and transparent to the totally opaque and closed. The project displays these halls for performing arts as “boxes or containers” in which music, dance and theater are performed. From outside we will not able to see what is happening inside but we feel that it is something important. The most significant in a hall for performing arts is that it must be completely dissociated from the exterior to create its own reality. The lights dim bringing the darkness, there is silence. Only in that moment the fantasy is spread as a new reality. The play has begun.
THE PREMISES AND BUILDING LAYOUT Horizontally viewed, the building layout is based on three main volumes or “buildings” containing the three major areas of the project. These are, from west to east in the same order as the buildings are set out: The Documentation Center for the Performing Arts and Music (Library); Training Room for Performing Arts and Music (Rehearsal Rooms, Museums and Exhibition Halls) and the Great Concert Hall (Theater for 2,000 people) On the level of the public space, these three buildings are separated and can be totally encircled by pedestrians and make the most of the project, but in the lower levels they are all connected making up one single building. The spaces between them have been transformed into covered squares that are the main public spaces and invite the passer-by to occupy a building that merge into the city. The first two structures facing eastwards are part of the redesigning of the existing building which survived the fire whereas the remaining structure (The great Concert Hall) is a new work. Viewed vertically, the premises are connected through triple height halls in which we have an overview of the project and find our bearing in each building. These halls are connected directly to each one of the squares being an extension of them. This is reinforced by using the same type of concrete indoors and outdoors avoiding the vertical structural elements in this enclosure and achieving a high degree of transparency . DESIGN AND MATERIALS All the main materials making up the building have been found in the original structure and it is worth to stand out five of them: Weathering steel (Corten steel), Exposed reinforced concrete, Glass, Steel and Timber. We don’t think in the use of these materials as they appear listed on catalogues but as construction materials that are taken to the limit of their expressiveness. Weathering steel is the perfect link between past, present and future. This fine material is far from being part of the “pre-painted” solutions and imitations. It is present in the original structure and now we try to take it to the extreme in the new building by using it as coating for facades, ceilings and concrete. This material has also been used in its varied forms such as perforated, smooth, folded and standard. Its quality over time still amazes us. This coating, which is mostly used in our facades alternating with glass curtain walls and large windows follows two basic plays and several secondary ones. In the first basic play we find perforated weathering steel that is the skin of the building and tries to cover it all over, but when there are premises inside the building and they deserve being watched from the exterior, the view of these elements is interrupted and a glass volume appears revealing a fascinating interior. This is the case of the dance rehearsal room, the reading room in the library and other halls in the building. The second play is the appearance of the glass boxes that deforms the weathering steel surface producing folds that change completely the way which the light is projected on the facades. Combining these two plays it creates a curious sort of spontaneity in the design preparing us to future readings. Only one type of concrete has been used in the project both interior and for the exterior squares and strips of weathering steel of 3,9 x 46,8 inches have been placed randomly on it.
RESTORATION AND RELOCATION OF UNCTAD III ART COLLECTION Many artists were convened by the original UNCTAD III project to create pieces of art specially made for the building. Many of these works were already integrated to the architecture of the building such as the vitraux ( stained-glass window) by Juan Bernal Ponce and the works of Nemesio Antunez and Felix Maruenda. Only few of these works survived to the passage of time and the different users of the building. In this way fourteen pieces of art available in the original building have been integrated harmoniously into the new project. Sculptures by Sergio Mallol, Sergio Castillo, Marta Colvin and Samuel Román were relocated in the new building. Juan Egenau´s door was restored and installed as an access to the exhibition room of the Museum of American Popular Art (MAPA). The vitraux by Juan Bernal Ponce was restored with modern technology and relocated on one of the main square`s deck. Door’s handles by Ricardo Meza and pictures by José Venturelli were also relocated to cite some examples. However, we believe this is only a little part of the task. From our point of view it would be ideal the retrieval of the majority of the pieces from the UNCTAD III art collection and outnumber the fourteen pieces retrieved (35% out of a total of 40 original pieces ). So we may retrieve 5 works (two works by Roberto Matta, two by Roser Bru and one by Gracia Barrios) currently being exhibited in other museums, through administrative resources adding up 18 works(45%). Other six works that might be rebuilt (four handcrafted works by Manzano_we have information about a group of craftsman that are able to make similar pieces from an existent model_1 relief by Iván Vilches from which there is a scale model, 1 mural painting by Nuñez who is willing to assist in the restore of his work. So we totalize 25 works of art retrieved, this is a 60% of the total collection. The thirteen works remaining could be replaced by works of the same artists. It is obvious that this course of action seems suitable given the UNCTAD III Collection have a high patrimonial and artistic value and required additional efforts by all parties involved, many of them anonymous, at the beginning of the project but it is well worth mentioning.
STAGECRAFT AND ACOUSTICS The building has a sophisticated acoustic and staging system necessary for the main activities. From the acoustic point of view each room was treated independently seeking an acoustic comfort according to each activity. Generally the acoustic solution consists in a double inner layer separated from the structure which depending on its position and function in each room so that they comply with spreading, reflecting and absorbing functions. Each case went through a design proposed by architecture in coordination with the acoustic engineer. In this way the Music Hall presents a design of sloping planes and hinge lines able to point the sound towards the audience in a good way and at the same time bring a contemporary and warm expressiveness to the hall. In the case of the Dance-Theater Hall we opted for a more sober expressiveness with a design of dark folded sheets made of tongue and groove joint boards. Both halls have lighting and audio control rooms placed at the back of each hall replacing the old translation booths. The building has also a staging system unique in the country including all the elements and equipment necessary for a proper performance. As to the Dance-Theater Hall this has a lighting grid system, illuminating rods and state-of-the art lighting bridge system. Illuminating rods operates automatically whereas the staging rods work manually by using ropes and pegboards. The Great concert hall has a complex stagecraft system including lighting and audio&video booths; three illuminating bridges for the stage lighting, fireproof curtain, staging and illuminating rods (manual and automatic) and the appropriate space needed for the proper functioning of these facilities such as lateral shoulders and the chapel. In addition the stage includes an automatic system in order to switch sceneries which they can be prepared in the lower levels and then mechanically move them upwards back to the stage.