De l'acoustique des églises en Suisse

The existence of the fundamental conflict in churches between the desirable acoustic conditions for music and for speech intelligibility prompted this dissertation. It tackles the subject not only under the acoustical perspective but also in the historical, theological, musicological and architectural aspects. This research studies, initially, how during the past, the liturgy, the acoustical and organizational characteristics of churches supported one or the other of these attributes. The second chapter presents the objective analyses of many Reformed worships and Catholic masses which make it possible to show the conditions and requirements for the current Christian celebrations in Switzerland. The analysis of the church geometrical parameters (volume, height, etc.) and of the results of objective acoustical measurements (reverberation time, background noise and speech intelligibility) of approximately two hundred churches in Switzerland allows to statistically describe their characteristics and to objectively verify the assumptions made in the preceding chapter. Chapter 3 also studies the local or global range of conclusions by the comparison of the results obtained in Switzerland with those published for other countries (synthesis of about 400 churches). The study of the origin and the interaction between Liturgy and Acoustics passes in particular by the analysis of the history of sacred music but especially by the examination of the main methods implemented to improve the acoustics of churches. Chapter 4 presents the historical evolution and the acoustical effectiveness of two types of devices used in churches: acoustic pots and pulpits with their canopies. The position of the various participants does not influence only the listening conditions but also reveals the importance attached to their participation. Chapter 5 examines then the historical evolution and statistical analysis of the current conditions regarding the position of the organ, the spatial arrangements for the seated congregation in churches, as well as the effect of the occupation on reverberation time and speech intelligibility. Chapter 6 concludes with the analysis of the desirable acoustical conditions in current churches, particularly with regard to the architectural, organizational (sound system, assembly arrangement and organ location) and the acoustical parameters (reverberation time, background noise and speech intelligibility). This last analysis is based on a significant bibliographical synthesis and on the comparison, for the sampled churches, of the results for objective measurements with the subjective evaluations obtained by a parishioner's sample survey.

Densité et logement collectif

Nicolas Bassand

As a measurement, built density (coefficient of land surface to be built and total floor space) has been the object of numerous researches on urban morphology and architectural forms during the twentieth century. However, for the last ten years, its sensory and qualitative dimension seems to be particularly valued: the perceived density. In multi-unit housing, dense, innovating and compact forms show a significant change of architectural and urban conception. In fact, project practices seem to have been marked by three major changes. Firstly, the importance of the precept of sustainable development, attempting at reducing urban sprawl. Secondly, the increased interest in urban values and the idea of "building a city within a city". Lastly, the current asserted need to redefine density: on one hand, new means are being researched to control it, on the other hand there is a widening of its definition due to the main impulse of architects and researchers. Within this framework, it is illuminating to reconsider the multiple disciplines using this term, as well as the distinct spatial scales tackled in this notion and changes in its use through time. However, focusing only on built density, the present research concentrates on the architectural and urban framework, also known as physical density. It is measured by a density figure but is also qualified by the perception of density. We propose as preliminary approach, an examination of this perceived density in fields where it is more frequently used, such as literature, painting and music. Another important notion of this research requires definition: architectural and urban innovation. Standing out from pure invention, this type of innovation consists essentially in a reinterpretation of previous architectural and urban productions worth naming "retro-innovation". Despite a housing program dependent on past models reluctant to rapid and important changes, radical innovations do occur, though more seldomly. Several ''moments'' of the collective housing architectural history allow for an updating of the different stakes manifested in the density – innovation relationship. Density perception plays a large role in a particular problem emerging from these two notions in contemporary Switzerland. The issue is how encouraging people coming back to the urban centers by proposing larger apartments with more square meters and urban architecture composed of numerous and various spaces, but protecting them at the same time from too close a proximity between neighboring housing and from environmental nuisances. The state of the art brings to light the enormous influence of the researcher and anthropologist Amos Rapoport on perceived density starting with his article, "Towards a Redefinition of Density", published in 1975. For more than thirty years now, architects, psychologists, city planners and geographers refer to this work when defining this notion in their respective fields. As a consequence, it nourishes several reflections in this research. Following these various observations, we propose the analysis of fourteen contemporary multi-unit buildings. They represent the current urban stakes at play and show the architectural and urban conception facing the double requirement of density: to insure a high enough floor area ratio (measured density) and to qualify the housing density (perceived density). In parallel, this research determines if this conception, unique to dense multi-unit housing, tends to modify architectural practice. In the first phase, we examine seven rectangular housing units, in which the width of the building is significant, and seven courtyard buildings in order to examine the exterior spaces contained by the building's volumes. In the second phase, we focus our attention on the wall expression of the fourteen buildings. In this way, these distinct analyses offer three new definitions of the perceived density expressing conception aspects particularly significant for understanding the architecture and urbanity of these dense multi-unit buildings. As a fundamental knowledge, it is shown that density, within the corpus, orientates the architects project's mode. The frequent reinterpretation of paradigmatic dense lodgings is one of the most striking proof of this conceptual change searching for innovations in the register of collective housing. So, in the density of depth, introversion and anonymity on the exterior seems to encourage distinct individualized space within the building as common domestic spheres only opened towards the inside of the apartment. In several cases, the usual urban and public spaces are integrated into the private interior of the apartments as if to domesticate a certain urbanity. In the density of the void, the proposed introversion of semi-public courtyards seems to help maintaining a larger sense of community in these multi-unit buildings. Altogether, it demonstrates a particular capacity to produce small cities within the city, at the same time independent and linked to the city. Finally, through the analysis of wall density, the exterior materiality and expression, dynamic or static, monumental at times, present a decidedly urban architecture enhancing a compact city in quest of new inhabitants.

EPFL2009

La leçon d'architecture d'Auguste Perret en Suisse romande

The thesis comprises 3 sections: first a methodological description, then an analytical and theoretical exposé, thirdly a study devoted to the five protagonists within the confines of the study. The methodological description is a presentation of the "Archives de la construction moderne", the laboratory within which our work took place, and its ethical, as well as its scientific and technical methods. This promotes continuity for a vaster project and fits into a continuum. The second section is an exposé that synthetizes numerous theoretical directions that allow us to focus on those subjects elected by our research : Auguste Perret's Architecture, the "Classicisme structurel" School, Swiss Architecture from the end of the thirties to the seventies, the notion of school and student in architecture, transmission of knowledge and models and crossbreeding within the scope of a constructive context. We also broach on certain guidelines of architectural analysis used in our third section in reference to different built or projected objects. These analyses are founded on volumetric studies, urban form and implantation, as well as the relation between structure and interior lighting concepts within buildings, construction analysis through materialization and implementation, and the use of façade composition and intended meaning and finally the coexistence of the old and the new within a work and its components. We also evoke the ramifications of our study in the larger architectural field comprising French Switzerland in the second half of the twentieth century. The third section has five parts devoted to archive contents constituting our basic research material, material we attempt to rationalize with a scientific catalogue of archive funds through both an architectural and chronological analysis of a series of finished or projected works as well as points of reference from author biographies and career paths. As an appendum we reproduce both a Joseph Abram text that served as the basis for our questioning and a complete study of Fribourg's Christ-Roi Church, emblematic of the architecture within this research.

EPFL2000

Construire à distance

Habib Sayah

Through a case study, this research aims at contributing to the historic understanding of the international architecture after the Second World War. It is based on the monographic analysis of the projects realised by the Geneva agency Addor & Julliard in Lebanon during the years 1950 to 1960. The general theme of "constructing at distance" embraces and problematizes two types of considerations: on the one hand, the challenges that international architecture of the years 1950-1960 had to face when the operations of conception and execution where realised in different contexts (i.e. functional and technical challenges due to climatic imperatives; logistical challenges linked to the characteristics of the local culture of construction ; strategic challenges in relation to the specific political and economic situation in the developing countries) ; on the other hand, the specific creative opportunities that the internationally active agencies were able to seize abroad and of which also their local production took advantage (treatment of prestige programs and ambitious operations with partners open to avant-garde experimentations). The operations realised at distance by the Geneva agency Addor & Julliard in Lebanon constitute an architectural corpus of approximately ten buildings in the urban and suburban zone. These realisations, which are not well known in the circles of researchers and architects, both locally and internationally, deserve to be analysed in detail, as they are very representative for the atmosphere of experimentation during the years 1950-1960 in Lebanon and generally in the other contexts of north-south collaboration. The work of the agency Addor & Julliard is still not well known in Geneva, with the exception of some publications on important projects like the Cayla campaign, or the Budé and Lignon blocks. Especially, the importance of the profitable interactions that the agency was able to establish between its two fields of activities in Geneva and Lebanon, and its significance for the development of this big agency, have not been stressed enough. The introductory part of our work situates the actuality of the problematic, in relation to the specific stakes of the protection of architectural and urban heritage in Lebanon. Still today, the heritage of the 1950-1960's is insufficiently understood in its cultural significance. It is also very much threatened. When it is not destroyed, it suffers from a camouflage that makes it totally unrecognisable. We then present the abundant documentation that we have gathered. This work on source material is necessary to counteract the superficial prejudice with which this architectural corpus is confronted. This part is then followed by a historical chapter on the agency Addor & Julliard before the opening of its Lebanese branch, as well as an overview of the Lebanese context between the beginning of the XXth century and 1960. These elements allow us to assert that the decisive factor allowing the agency to develop its foreign activity is to be found in the profile of particular competencies that it displayed by closely associating the architectural project and the real estate management. The apartment- and office-building realised in 1954 in Geneva the Zschokke enterprise, with its easily adaptable spatial organisation, played the trigger role : it encouraged the first Lebanese clients, the Beydoun family who had financial relations in Geneva, to mandate the agency for a project involving a multifunctional building in Lebanon. The Lebanese context of this period is characterised by a strong economic boom and a political stability conducive to investments. The real estate sector was in full growth and asked for innovative typologies and modern architectural images. This allowed the agency Addor & Julliard to emancipate itself from the still quite regionalist references that it was entertaining in Geneva and to direct itself resolutely towards the international tendencies. These elements of historic information are then followed by the detailed survey of the agency's Lebanese production. Several buildings were realised in Lebanon, Syria and Iraq, but it is in Lebanon that the principal operations are concentrated, which explains that the survey limits itself to this country. The inventory concerns the ten buildings that have been spared from the destruction of the Lebanese War (1975-1991) and of which the archive documents have been preserved. The description of each object includes the history of the commission, the urban situation, the legal and regulatory situation, as well as the project variants when they exist. Then, the realised variant is analysed in detail by paying attention to the distributive, constructive and stylistic aspects. This survey then leads to a more interpretative reading that aims at evaluating the impact of these constructions on the urban development of Beirut. Addor & Julliard never had real town-planning mandates in Lebanon. But even though their realisations limited themselves to the architectural scale, they nevertheless contributed to the concretisation of a resolutely modern representation of the city, especially because they succeeded in treating orders of a considerable symbolic importance. The theme of "constructing at distance" is addressed via a comparative method that integrates the Lebanese, Geneva and international projects of the same period. This chapter also deals with the contribution of the buildings of Addor & Julliard to the local Lebanese construction culture on both the technical and expressive level. The demonstration is based on the curtain-wall that Addor & Julliard used twice in two very different buildings: the STARCO centre (1954-1962) and the Lebanese Bank (1962-1963). The in-depth analysis of the conception and the realisation of the curtain-wall, emblem of the "international style", allows to discover that in Beirut its use resulted much less from the importation of generic and abstract solutions than from a skilled synthesis between technical resources, which were locally available, and the aimed-at iconic effect. We thus perceive that "constructing at distance" is more complex than a simple knowledge transfer from one environment to another. The local differentiation of constructive elements of the international repertoire between 1950 and 1960, such as the curtain-wall, prompts us to question and complement the analysis of Hitchcock et Johnson on these phenomena in their famous publication "The International Style" of 1932, which seems too superficial. Our study finishes with an advocacy for the protection of the projects of Addor & Julliard in Lebanon. Without being exhaustive, this advocacy is based on the examination of the transformations touching these projects until today and establishes a series of recommendations for their protection. It is said that in Lebanon modern architecture of the years 1950 to 1960 constitutes the witness of the efforts undertaken in this period by the local actors in order to emancipate their country from a certain marginality in international relations. For this reason, the modern heritage fully belongs to the Lebanese history. The annexes especially contain the data bases, which we have constituted during the inventory of the projects and the archives, as well as some particularly important documents: The contract established between the architects and their first client represents the start of their work in Lebanon, whereas the minutes of the press conference of 21 March 1963, during which the Society of engineers and architects of Beirut criticizes the work of Addor & Julliard in Lebanon, symbolises the end of their Lebanese collaboration. Finally, an album exposes the photographs of the buildings of Addor & Julliard at the time and in their present state. ------------------------------ 3 Imm. Zschokke à Genève. In Werk, Bauen & Wohnen, 1957: pp. 367-368. 4 Lambert, S., STARCO Center, Beirut, Lebanon. UK, in Architectural Design, Mars 1963: pp. 138-140.

EPFL2007