Transformation of the Montparnasse Commercial Center | RPBW - Renzo Piano Building Workshop

Renzo Piano Building Workshop Reimagines Montparnasse Commercial Centre and CIT Tower as a Pedestrian-Focused Urban District.

Commissioned by the co-owners of the Montparnasse Commercial Centre and the CIT Tower, Renzo Piano Building Workshop (RPBW) has unveiled a transformative vision for the Ensemble Immobilier Tour Maine-Montparnasse (EITMM), reinventing a 1970s low rise retail development into an open, vibrant, and inclusive piece of city. Developed in parallel with the redevelopment of the Montparnasse Tower led by Nouvelle AOM, the project reshapes one of Europe’s largest private tertiary complexes into a contemporary Parisian block rooted in public life, sustainability, and everyday use.

By reopening the site to the city, reconnecting streets, and creating generous public spaces, the project restores continuity between Montparnasse and its surrounding neighborhoods. Architecture is conceived not as an object, but as a framework for movement, encounter, and openness - where culture, commerce, housing, sport, and landscape come together to support daily life. Sustainability, greenery, and accessibility are embedded at the core of this renewed Montparnasse.

A Storied Site in Need of Reinvention
Constructed between 1969 and 1973 by AOM on the former Montparnasse train station site, the EITMM is composed of three distinct elements: the Montparnasse Tower, the commercial center, and the CIT Tower, which sits above the retail slab. While emblematic of its era, the complex reflects a period of slab-based urbanism that prioritized separation and inward-facing retail over permeability and public space.

In 2022, RPBW was commissioned to develop a new vision for the commercial center, responding to profound changes in retail models and the evolving needs of Parisians. The project was temporarily paused in 2023. With design work resuming in 2025, and leading to a refined direction bringing into alignment the ambitions of the clients, planning authorities, and environmental stakeholders, while integrating a comprehensive approach to both the commercial center and the CIT Tower.

This shared ambition was formally endorsed in late 2025, when the Council of Paris voted in favor of the project in a rare multipartisan show of support. On January 7, 2026, the City of Paris and the EITMM co-owners signed a protocol agreement, marking a key milestone and confirming their joint commitment to revitalizing this strategic site at the heart of the Left Bank.

Reconnecting the City Through Public Space
At the heart of the project is a fundamental urban gesture: opening the block and stitching it back into the city. New pedestrian routes cut through the site, reconnecting Rue de Rennes, Montparnasse station, and surrounding streets, while linking three Parisian arrondissements. Ground floors are reimagined as transparent and permeable, creating continuous visual and physical connections between the public realm and the interior of the block.

The central piazza forms the true beating heart of the project. Larger than the Place du Marché Sainte-Catherine in the Marais - measuring approximately 40 by 40 meters - this generously planted public square is directly connected to surrounding streets and major public spaces, becoming a destination not only for the neighborhood but for Paris as a whole. Sheltered from surrounding traffic and shaded by a dense tree canopy, the piazza is animated throughout the day by cafés, restaurants, and terraces, offering a convivial setting for meeting, lingering, and daily life.

Opening onto the piazza, a major cultural facility of nearly 1,500 m² anchors the identity of the new district. Conceived as both a gathering place and a strong architectural signal, it offers a unique program dedicated to contemporary arts and music. Panoramic elevators and a sequence of belvederes connect this cultural venue to the central square, extending the public experience vertically through the project.

The uppermost belvedere provides access to a series of rooftop sports facilities.
Set against open skies and offering spectacular views over Paris, with six accessible outdoor multi-sport courts creating an unprecedented offering in the heart of the city. These facilities complement the existing Armand Massard sports center, which includes three swimming pools and fencing halls, with redesigned access points that improve visibility and accessibility from the site.

Retail surfaces are reduced by 28% compared to the existing condition, enabling a more selective commercial program structured around strong pedestrian flows and destination-oriented uses. The project’s clear form, measured density, and building heights - carefully aligned with the surrounding urban fabric and compliant with the bioclimatic PLU - allow the site to fully reintegrate into the continuity of the neighborhood.

Open to the public, the transformed block becomes an intimate yet lively place, conducive to encounters and daily use. Human-scale buildings contribute to a renewed quality of life while embracing the area’s existing character, at the crossroads of tourism, offices, leisure, and popular culture.

Building With What Already Exists
Sustainability is a driving principle of the project, expressed through a strategy of conservation, transformation, and limited demolition. The existing structural grid is retained as the backbone of the design, significantly reducing material consumption and embodied carbon. New volumes are introduced using lightweight timber structures, enabling the integration of new programs while minimizing structural intervention.

Excluding the Montparnasse Tower, the real estate ensemble - currently totaling 53,500 m² of offices and retail - will see its surface area increase by approximately one third. More than 10,000 m² will be dedicated to sports, culture, and housing, including 5,600 m² of student residences, 30% of which will be social housing.

By building with what already exists, the project demonstrates a pragmatic and forward-looking approach to urban renewal - one that reconciles architecture, uses, and public space in the service of a district in full renaissance.

Renzo Piano:
“C'est un projet d'une grande sagesse, avec un grain de folie”
“It is a highly thoughtful project, with a spark of audacity”

Albert Giralt:
“This is a surgical project that seeks to demolish as little as possible while radically transforming a hostile, inward-looking commercial centre into a vibrant Parisian urban hub.”