175 HAUSSMANN, adapting architecture to contemporary standards

ARCHITECTURAL STRATEGY

Restoring legibility and coherence
PCA-STREAM brings together two separate buildings: a classical Haussmannian building from 1863 and an Art Déco one from the early 1920s. The primary objective was to restore a high level of visibility and legibility to the building from the street. By freeing up the ground floor of No.175, the accesses could be shifted to the front of the building, designing a well-aligned entrance. A large chandelier magnifies the hall by producing an ample and spectacular volume. The restructuring brought the interior space up to date, adapting it to contemporary standards while also restoring coherence to the whole.

Acting as a beacon
PCA-STREAM relied on the idea of raising the construction to give a new image to the complex, while also optimizing its surfaces. The first of the additional floors was built in stone, in order to respect the balance of the masses, followed by two floors under a glass roof, giving the whole a unique aesthetic. It reinvents the identity of 175 Haussmann by contributing a very contemporary feature that integrates seamlessly to the historical context of the district. This new iconic landmark illustrates the symbolic role of the head office, which must embody the image and values of its inhabitants. A place to see and to see from, the singular spaces under this glass roof, midways between interior and exterior, are dedicated to socialization and holding events.

WELL-BEING AT THE HEART OF THE PROJECT

Embodying occupational well-being
The175 Haussmann had to respond to the changes in the way we work. The project thus pays particular attention to the design of service spaces, in the spirit of hotel lobbies, but also to furniture, which refers to codes that are more domestic than purely tertiary. The design is simple and sober with a view to make the office floors as open and fluid as possible. Fully modular, they aim for maximum flexibility to adapt to changing uses and combine comfort and efficiency. They are also very bright, thanks to a white and glazed dioptre inner facade featuring an innovative kaleidoscope system which allows natural light to be reflected and transmitted seven storeys below to the very bottom of the widened patio.

Fostering horizontality and exchange
Designing a new circulation core has brought about fluid and open floors offering a non-hierarchical horizontal distribution of teams. The office floors are completed by a high ratio of common spaces that foster interaction and informal collaboration. Widening the central courtyard has created a bright, convivial shared area that becomes a village square for the Lazard community. Housed under a large, triple-height glass roof, it is the place where employees and clients meet, exchange ideas or conduct informal work sequences.

Creating a dialogue between the “inside” and the “outside”
This dialogue is made possible thanks to the glass scales carring the two last floors as well as by a reconquest of outside space: the landscaped rooftop and the terraces at the sides of the building. 175 Haussmann also reconnects to its neighbourhood through the presence of a restaurant that is accessible from outside the building. Within a large, double-height volume, it is reserved for Lazard teams at lunchtime, but is open to the public outside of these hours. This desire to hybridize the company restaurant makes 175 Haussmann an active member of the local community.

AN AMBITIOUS ENVIRONMENTAL APPROACH

A state-of-the-art low-energy design
The building’s windows are designed so that they can all be opened and allow for natural ventilation that limits air conditioning and improves air quality, which is especially valuable in the current health situation. The passive energy protection systems are also supplemented by the installation of a renewable energy production facility using photovoltaic glass that is incorporated on the southwestern side of the glass roof.
Additional to the work to make the building thermally inert, the central and hyper-connected geographical position of 175 Haussmann has a strong impact mobility, thus improving the carbon impact of the complex as much, if not more, than the architecture itself. The presence of a large bicycle parking facility further encouragers users to adopt soft mobilities.

Exemplary water management
Special care is also given to set up an exemplary water management technique, in particular through the integration of a grey water treatment system using the phyto-purification potential of plants. Additionally, the building’s grey water is recovered and undergoes successive treatments in a series of tanks containing algae and aquatic plants that are capable of absorbing inorganic substances. The water thus recycled is used for the irrigation and watering of the vegetation on the terrace. Furthermore, a rainwater recovery tank harvests water for toilet flushing.

An innovative landscape and productive system that sustains biodiversity
Design of green spaces is not merely a decorative aspect. The restructuring of 175 Haussmann was designed to foster a reconnexion of the building and its users to nature. The planted surfaces form a coherent and connected whole, from the sixth floor to the roofs. With an exceptional panoramic view on Paris, the landscaped terrace offers a wealth of uses in tune with the seasons, bringing a sensory dimension of biophilia to the complex. An innovative vertical urban permaculture technique has been developed in collaboration with the start-up company Sous les Fraises. It uses a hydrological membrane as a vertical greening tool supports a complete ecosystem, fed by organic matter. Micro-organisms and plants live symbiotically, stimulating biodiversity.