Through this investigation, we strove to understand how the resulting urban form is the consequence of an intent, a design, a plan. The evidence yielded by the analyses conducted at different levels – from the urban networks to the vocabulary of the building components and their façades – reveals the intrinsic qualities of 55 the urban fabric of Haussmann’s Paris, both in terms of its physical setting – urban morphology, the characteristics of the built elements and their capacity for evolution – and its human environment – usages, modes of appropriation and adaptation or repurposing. Our study of Haussmann’s Paris reveals a fascinating urban form that, as a fractal structure, distributes full and empty spaces effectively at all levels. The Haussmann urban form does not initially appear to be a reproducible fabric – like a New York City block or Cerdà’s matrix in Barcelona –, but in reality, it presents specific characteristics that recur in each of its parts. The Haussmann fabric is the result of a triangulating grid that connects the city’s major signifying elements. It is made up of relatively generic frameworks that, regardless of their size, present a specific hierarchy of empty spaces through the ratio of built footprint to the ground, an identical level of built density, and a constant rate of porousness. The underlying idea of this study has been the comparison of the intrinsic characteristics of the Haussmann urban model with the concepts and ambitions of contemporary urban development that embody the values of a sustainable city: density, resilience, connectivity, legibility or identity, as well as sobriety, sharing or commonality, intensity, attractiveness, and diversity.

A consideration of the Haussmann type leads us back to a fundamental problem of urban form, namely how to optimize the relationship between full and empty spaces. This question underlies a number of dialectical if not contradicting rationales: building densely without generating a stressful concentration, creating clear, readily identifiable public spaces at a human scale, providing a high density of services that are nevertheless spread out to avoid congestion, enabling a fluid circulation using a rather thin urban framework without however creating excess roadways, controlling the loss of heat from buildings through morphologies that are compact and yet provide access to air and light, etc.

When observed at the level of road networks, blocks, and individual buildings, the Haussmann urban fabric reveals its ability to provide a relatively balanced response to the opposing needs of full and empty spaces. It has a high aggregation of thin elements characterized by their significant capacity to absorb and distribute natural resources evenly and in depth. The urban form provides a happy medium between a spontaneous, unplanned city and one consisting of the addition of discontinuous volumes inherited from our modern culture. The efficient, optimal grid generated by the road networks, as well as the maximum ground occupancy, the significant percentage of shared walls, and the even building heights have created a particularly high level of density in Paris; however, the lived density that this form produces is experienced positively.

The notion of resilience asks us to rethink the urban system in all its permutations. The challenge is to create a sustainable city by giving the urban system the capacity to absorb changes while preserving its structure. The operability of this concept requires to adapt the workings of the urban system and its components to potential changes in use, connection, and generally, any unplanned disruptions. The reversibility of the investment property – given the rigor and repetitiveness of its building frames, its hyperstaticity, its generous ceiling heights, the serial nature of its openings, construction modes, and use of materials – along with the high degree of the block’s flexibility, the coherence between the urban matrix and the infrastructure networks, as well as their initial oversizing, make Haussmann’s city greatly capable of transforming itself and evolving in response to changes in the physical, social, and economic environment.

The urban fabric of Haussmann’s Paris is characterized by a hierarchical, ramified network, and a finely meshed, highly connective urban grid. Permeable and easy to move across, it provides excellent accessibility and a high degree of mobility. It overlays fast, straight-line, wide road networks with slower, sinuous, lower capacity ones. The resulting organization is a coexistence of long and short distances, each one favoring specific modes of transit, from motorized transport to walking. The Haussmann urban model’s connectivity is also due to the exceptional infrastructure network that was implemented alongside the urban renewal and which maintains a continuously close relationship to the city above ground. 

In addition to the development of new road networks and the construction of buildings, modern water and sewer networks were also developed under Haussmann. The new streets have underground gallerias that form the particularly dense grid of sewers in Paris. Haussmann and Belgrand envision moving other fluids through these tunnels, such as potable water pipes and a network of non-potable water. The gas network is densified and the distribution generalized, among other reasons, to light public spaces. Gaslights make their first appearance, and buses begin to run along the network of new streets built for the collective transport of individuals. In the early 20th century, the subway rail network was built underneath the primary roadway network. It is an expression and enhancement of the coherence and interweaving of the road networks and urban usages above ground and the service infrastructure network below. This comprehensive conception of the city in terms of its urban and service components is the first expression of the ideas and practices of contemporary urban planning. It constitutes a reference for the environmental and energy efficiency challenges we face today, as well as for the questions raised by “smart cities,” which compel us to view the renewal of networks as inseparable from that of the city and its practices.

The radical nature of the Haussmann principle is based in particular on the clear separation of the “theater” of the street and the “backstage” of the courtyard. On the one hand, this deprives the public of the potential offered by the porousness of open or semi-open blocks (greenery, views, crossing passageways), but on the other, it provides a model in which the façade constitutes a true threshold between public and private space. The recognizable character of the built landscape, due to the type’s repetitiveness, the constant relationship of block façades to the public space, and the emphasis given to monuments that house collective memory all translate into a highly assertive urban identity. The Haussmann esthetic ideal functions at all levels. Each component, each piece of its urban fixtures – kiosks, public toilets, street lights– down to the railings, shutters, doorways, windows, the uniform roof materials, chimney conduits, façade materials, among many others, contributed to the creation of a very legible city that provides one of the best examples of architectural coherence in the world. Beyond the resilience of its urban framework and built heritage, Paris’ identity cannot be summed up in a single, fixed image. The urban frame-work represents the scene of a living collective memory that evolves with the society that inhabits it. This identity gives rise to a heightened sense of belonging and appropriation, as testified to by the endless number of literary texts that have lauded the city for its beauty. This acknowledgement directly challenges contemporary modes of urban development.

The sobriety of the urban fabric of Haussmann’s Paris resides in its high degree of accessibility, which can be measured in two ways: first, by a street network that is one of the smallest among the city sectors we studied, and secondly, by a ratio of the street network to the accessible portion of the built footprint that is also incredibly low (two times less than most of the cases studied and almost four times less than Moscow, for example, given the density of Paris’ built footprint). In other words, in the Haussmann fabric, access to the numerous built parcels requires less street. The high degree of the urban form’s compactness expresses a kind of frugality and effectiveness. The sobriety of the Haussmann fabric also applies to the formal and compositional grammar of its constituent elements, from the road networks to the language and style of the buildings’ organizational and ornamental components. This method of construction combines a small number of primary types with a rich, diversified amount of variations, as well as a few simple rules that apply to the various scales. This all serves to reinforce the fractal nature of Paris’ urban form.

The application of the principles of sustainable development to the construction of buildings highlighted the principle of compensation and independence as a search for the ideal. A building is environmentally sustainable only to the extent that it produces as much energy, food, water as it consumes. This quest, however laudable at a planetary level, is, on the scale of the built entity, in total contradiction with the very principle of the city. Sharing is the essence of cities. Human settlements originated with the idea of the common and the shared, whether in terms of resources, infrastructure, or services. Sharing in the Haussmann city is a result of the high quality of the urban fabric and the aggregating nature of the block, which consists of a varying number of buildings with strong connections and a significant amount of shared walls between them. As in a network, the diversity and quality of the connections are as, if not more, important than that of the entities forming the network. The block and the building say little on their own; they serve a greater urban interest in terms of esthetics and identity, as well as of resources and efficiency. Considered on its own, the Haussmann investment property seems energy-inefficient at first. It is not very compact and it has a large amount of façade area. Its qualities emerge when aggregated to the block, sharing walls with the neighboring buildings; at this scale, it balances performance with comfort of use. The high rate of shared walls accounts for a lot of this, horizontally in terms of the overlay of floors, and 50% of the vertical envelope’s surfaces. It provides effective insulation at a low environmental footprint due to a lesser use of materials. It also has a high rate of inertial storage that regulates and attenuates the thermal exchanges between the environments that it connects. As a note-worthy consequence of this synergy and sharing between buildings, the energy consumption of the Haussmann fabric is much lower than what one would expect to calculate.

The exceptional density created by the Haussmann fabric, the highly varied potential usages of the ground floors of the investment properties that make up this fabric, and its excellent connectivity all explain the city’s exceptional liveliness. Independent, reproducible, and transposable, these typological and morphological criteria help make Paris a particularly successful example of urban intensity. From a quantitative standpoint, Paris’ fabric is characterized by a very high number of businesses and services of all kinds, as well as by their homogenous distribution. This reveals the diversity and coherence of the neighborhood unit. In a way, one could say that Paris is characterized by an intensity that is once homogenous and widespread, which translates into a form of polycentrism.

In the last decade, attractiveness has become a crucial factor for cities. A city’s attractiveness can be measured at once very objectively, using various economic, social, and cultural indicators, and subjectively, through opinion surveys or urban audits. Paris is fourth among the most attractive cities in the world, according to the latest ranking conducted by PwC[1]. In addition to urban, demographic, economic and cultural policies, the city’s construction has a significant impact on this ranking. In Paris’s case, the high level of density and the homogenous, widespread supply of services across its entire expanse, an identity based on established, generalized esthetic values, and the high degree of reversibility of the urban structures and built ensembles that enable the embracing of new lifestyles at any moment are inherent qualities of the city inherited from the Haussmann urban model.

Diversity is an essential factor in a city’s coherence, because it enables the peaceful coexistence of essential, heterogeneous functions of the city and the diverse populations that inhabit it. Along with the density and polycentrism, it also helps reduce the need for movement. Diversity is multifaceted; it can be functional or program-based, social in its many forms, or generational. Diversity is the result of political decisions, the definition of urban rules and the implementation of the tools that urban planning offers. Considered in its various aspects, it a priori depends little on a city’s infrastructure, both as regards its form and the structure or composition of its buildings. At the same time, as with the notion of walkability, which represents the elevated potential of pedestrian mobility in a city, an urban structure’s ability to welcome functions and diverse populations, which we can define as its “hospitality,” undeniably constitutes a factor of diversity. From this standpoint, the Haussmann urban form presents several major advantages: at the scale of the city, its hosting from the outset of service functions (rail infrastructure, logistics spaces, potable water reservoirs, etc.) whose onsite maintenance constitutes one of the main challenges of current urban development projects in Paris, and especially its extraordinary properties of malleability, flexibility, and reversibility of the typical figures of the block and the building. The ease of densification or de-densification, regrouping and de-grouping, the hosting of diverse functions at the block level, the possibility of re-placing one building with another within a block, as well as the capacity of the Haussmann investment properties to host any type of program at the same time and across the years (housing, offices, businesses, shops, etc.) without this changing their spirit or urban expression, all constitute determinant elements of the high level of program diversity in the city, down to the level of the building and even each individual floor. Although Paris is characterized by its high population density – the highest of any European city – it also hosts a considerable density of jobs. According to the APUR’s figures compiled in 2004[2], Paris’ population density is more than 200 inhabitants per hectare, 30 % higher than that of Barcelona for a similar surface area, two to two and a half times that of Berlin and London respectively, and six times that of Amsterdam. The trend is even more pronounced in terms of density of employment: at 160 jobs per hectare for downtown Paris, it is 70% higher than in Barcelona, two and a half times that of Berlin, more than four times that of Brussels and London, and eight times that of Amsterdam. One should note that these population and employment density trends remain the same at the scale of the greater metropolitan area, and with less pronounced deviations between them. Moreover, Paris’ employment density today is relatively constant across the entire city, to the exception of certain arrondissements (the 2nd, 8th, and 9th), where it is higher. Throughout the Haussmann fabric of Paris proper and its variations outside the city walls, the city’s great “hospitality” can be measured in terms of an urban density and functional diversity that are both unrivaled and relatively homogenous in terms of distribution. The result for mobility is that 68.4% of Parisians work within the city and only 31.6% work outside Paris.

At each level and in terms of each component, the urban fabric of Haussmann’s Paris expresses a set of characteristics that guarantee several fundamental forms of equilibrium: between density and viability, permanence and resilience, sobriety and diversity, connectivity of long and short distances, identity and universality, intensity and a welcoming urban spirit, and between attractiveness and inclusiveness. At a time when the metropolis is reexamining its geographic identity and spatial effectiveness, Haussmann’s Paris provides an example of a feasible model. This model is the result of a design and a plan. It lies at the origin of a multifaceted project that embraces several large divisions that come together to form a whole that is complete and harmonious.

 
  At each level and in terms of each component, the urban fabric of Haussmann’s Paris expresses a set of characteristics that guarantee several fundamental forms of equilibrium: between density and viability, permanence and resilience, sobriety and diversity, connectivity of long and short distances, identity and universality, intensity and a welcoming urban spirit, and between attractiveness and inclusiveness..  


In his own way, Haussmann himself rendered homage to the people to whom we owe this heritage : "I shall forever be obliged to repeat the truth about the majestic boulevards I built across this city, which has become unrivalled in our entire universe, as well as the other large prodigious works that have made it so beautiful and for which I receive credit, because I was able to complete most of them, despite all opposition, jealousy – did I just say that? – and so many profound betrayals. I must nevertheless recall that the idea for this unparalleled initiative first came from Emperor Napoleon III, who brought me from Bordeaux to Paris, who used me as his tried and tested agent, as a trusted instrument, unreservedly devoted to the fulfillment of his grand ambitions. Later on, I in turn also brought Mssrs. Alphand, Belgrand, and many other less well known people from their respective provinces to stand in for me, each in his sphere[3]."


In the book « Paris Haussmann. Modèle de ville » published by the Pavillon de l'Arsenal in 2017.

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1. “Cities of Opportunity 7,” September 7th, 2016, a yearly ranking by the firm PwC on the basis of a range of thirty cities worldwide analyzed according to ten indicators and sixty-seven variables that measure everything from the social to the economic health of the leading cities in terms of commerce, finance, and culture.
2. APUR, “Movements in European Cities,” January 2004.
3. Memoirs of Baron Haussmann [1890-1893], 2 volumes, Paris, Guy Durier éditeur, 1979.

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LAN, Benoit Jallon and Umberto Napolitano
LAN (Local Architecture Network) was created by Benoit Jallon and Umberto Napolitano in 2002, with the idea of exploring architecture as an area of activity at the intersection of several disciplines. This attitude, which has now become a methodology, allows the agency to explore new territories in search of a vision involving social, urban, ecological and functional issues. The firm’s projects reflect this spirit of openness and cover a wide range of scales and programs : the Maillon Theatre (Équerre d'argent 2020), the Euravenir Tower (nominated for the Mies van der Rohe Award 2015 and Prix Soufaché of the Academy of Architecture), the experimental housing in Bègles (Venice Biennale 2016), the student residence on Rue Pajol in Paris (first national BigMat prize), the EDF Archive Centre (Leaf Awards 2011), the Neue Hamburger Terrassen (International Architecture Awards in 2014) are some of the iconic operations that the office has produced over the last two decades. LAN is currently working on projects in Europe (France, Belgium, Germany and Slovenia) and is expanding internationally through experiences in the Middle East and Asia.

Franck Boutté
Franck Boutté, architect-engineer, founded FBC 15 years ago, a creative engineering and environmental co-design workshop made up of 35 complementary profiles, engineers, technical experts, sustainable development consultants and designer-architects, who work on a daily basis with real estate and regional players.