The Latin phrase carpe diem is translated into English as "seize the day". The recently unveiled plans for the Tour Carpe Diem office building in Paris show a tower that will live up to that phrase by seizing sustainability. Designed by New York-based Robert A. M. Stern Architects for insurance company Aviva France, the 35-story tower, or “tour” in French, is expected to meet or exceed French regulations for ecologically responsible development.

The 484,392-square-foot (45000-m2) building, which is expected to break ground next year and be completed in 2011, is planned for La Défense, a high-rise business district in west Paris located along the axis of the famous Champs-Elysées. La Défense is named for a statue called “La Défense de Paris” built in 1883. The business district encompasses nearly 78 acres (32 hectares) and includes the tallest and most architecturally audacious buildings in Paris. Yet the district lacks the 24-hour vitality of downtown Paris; after the workday ends, La Défense essentially shuts down.

In 2006, however, l’Etablissement Public d'Aménagement de La Défense, or EPAD, the public authority that manages La Défense, launched a nearly decade-long effort to revitalize the business district by 2015 and turn it into a vibrant place to work and socialize while promoting state-of-the-art sustainable technology. Several new high-rise buildings, featuring the work of such U.S. firms as Pei Cobb Freed & Partners, New York; Kohn Pedersen Fox, New York; and Arquitectonica, Miami, have been planned as part of this effort.

  • Credit: Robert A. M. Stern Architects

“This is a fantastic opportunity to place greater emphasis on the human dimension at La Défense,” said Robert Stern, FAIA, Robert A. M. Stern Architects’ founder and senior partner, in a statement unveiling the design.

TOWER OF POWER
Despite its imposing height, Tour Carpe Diem is designed to promote pedestrian use and connectedness on a human scale. The building is sited so it will serve as a link between La Défense’s raised boulevard, the “dalle,” that connects to the Champs-Elysées and the city of Courbevoie to the north. The faceted façade seems to point in two directions at once—an effect the firm calls “Janus-like,” referring to the two-headed god of openings and doorways in Roman mythology, in its orientation to the dalle and Courbevoie.

“La Défense is a fascinating place,” says Meghan McDermott, RA, a partner with Robert A.M. Stern Architects who is serving as co-principal on the Tour Carpe Diem project with partner Kevin Smith, AIA. “One of our first goals was to open up La Défense and reconnect it to Courbevoie. The faceted design was a response to the geometries of the buildings adjacent to Tour Carpe Diem and creates a distinct identity on this small footprint.”

To foster this sense of connection, a landscaped pedestrian walkway, which includes a reflecting pool and outdoor cafés, will lead to the building’s 59-foot- (18-m-) high skylit winter garden and lobby. Two levels of parking below grade will include space for 106 bicycles; showers and changing rooms will be available for those who bike to work.

  • Credit: Robert A. M. Stern Architects

Triple-glazed windows will feature integrated vertical louvers that allow users to moderate low morning and evening sunlight. “With Carpe Diem, there will be three layers of glass on the exterior, which contributes enormously to the R-value of the façade,” McDermott says. “The actual glass façades are treated differently according to the solar orientation.” The south side, for example, will have a particularly strong low-E coating and exterior glass will feature frits, a baked-on ceramic material that increases reflectivity but is nearly invisible to occupants. Innovative sunshades will respond to the solar orientation of each elevation.

Horizontal vents will be incorporated into the façade coincident with the ceilings, providing natural cooling and reducing the building’s reliance on air conditioning. “It’s natural air ventilation that is pulled across the ceiling,” McDermott says. “It’s free cooling for the building.”

The building also will use a heat-recovery system to gather free energy. This system recaptures exhaust air off the roof and pumps it back into the building to provide extra energy for heating or other mechanical systems.

Other planned sustainable elements include solar-water heating, rainwater harvesting, a vegetated roof, low-emitting carpet, highperformance lighting and locally produced materials wherever possible.

TOPPING THE STANDARD
When completed, Tour Carpe Diem is expected to be certified under the French green-building standard known as Haute Qualité Environnementale. HQE is a voluntary program that includes 14 criteria that address a building’s energy efficiency, environmental quality, user comfort and public-health effects. The standard, which is administered by Paris-based Association pour la Haute Qualité Environnementale, currently is available for office buildings and soon will be expanded to include other building types, including retail, hospitality and sports facilities. Buildings certified under HQE are required to undergo three audits—one during design, one when the project is complete and one when the building has been operational for a set period of time to ensure it is operating as prescribed.

  • Credit: Robert A. M. Stern Architects

Tour Carpe Diem also is expected to meet or exceed RT 2005, France’s rigorous regulation to control energy emissions and reduce greenhouse-gas emissions. “We are excited to be working on this project and are committed to pursuing energy-efficient solutions for this building,” McDermott says. “We’re thrilled that our French clients and EPAD are absolutely committed to this project, as well. We’re learning other interesting approaches just by working with our French partners.”

Kim A. O'Connell writes about architecture and sustainability from Arlington, Va.


TOUR CARPE DIEM: Paris

  • OWNER / Aviva France, Paris, www.cgu.fr
  • BUILDING MANAGER / EPAD, Paris, www.ladefense.fr
  • ARCHITECT / Robert A.M. Stern Architects, New York, www.ramsa.com
  • ASSOCIATE ARCHITECT / SRA Architects, Châtillon, France
  • GREEN-BUILDING CERTIFICATION / Association pour la Haute Qualité Environnementale, Paris, www.assohqe.org