Header: Vladimir Partalo
Rotterdam studio STAR Strategies + Architecture has recently finished START-Ivry, a group of five housing towers in Ivry-sur-Seine, on the southern edge of Greater Paris, where the Seine meets the Marne. The practice, led by Spanish architect Beatriz Ramo, designed 288 homes that mix social, intermediate and market-rate flats in a single development.
The towers are located right by the river, which means that about nine in ten of the flats face two or three directions, many of them looking onto the water. The project won an award in the Social Housing category at the BLT Built Design Awards 2025, one of a long run of prizes it has collected over the past two years.
The idea
STAR built the project around a simple vision: that a home should change as the people inside it change. START stands for “Social, Transformable, Affordable and Resilient Typologies”, and the studio’s motto is “form follows life”.
The starting point was the floor plan and the resident, and everything on the outside grew from there. The city even turned the usual order of hiring on its head, choosing the architect first and then inviting developers to compete for the job, which gave the design team unusual control over the plans. START-Ivry is the culmination of more than a decade of the studio’s work on housing that can adapt.
Flats that can be divided and rearranged
The flats were drawn so they can be split or joined without any change to their overall size. A large multi-bedroom flat can become a self-contained studio, while a two-bedroom type can take in a lodger, a relative needing care, or a home office. Small extra rooms the studio calls “plus” and “bonus” alcoves work as studies, sleeping nooks or workspaces. Kitchens can be moved to free up another bedroom, neighbouring flats can be combined, and doors are positioned so that a divided-off part can gain its own entrance.
Making this work meant careful placement of the parts that are hard to move later. The architects lined up the wet spots (meaning, the walls carrying water and drainage) and grouped the service shafts so that any future plumbing change stays small and cheap. Corridors were left short or put to use as storage, and every kitchen and bathroom has a window, which cuts the need for electric light during the day. Storage is spread through each flat so the living rooms stay clear and can be re-partitioned when a household changes.
Slender towers and a working façade
The towers are only about 14 metres deep, very shallow for buildings that rise to 56 metres. That thinness lets daylight reach far into each flat and lets air pass straight through from one side to the other. The façades don’t have a standardised look, instead taking the shape of how the building is actually used: windows, balconies, loggias (recessed balconies set into the wall) and small projecting boxes are placed wherever the flat behind them needs them.
The ground floor and shared space
At street level, a plinth holds 14 retail units, space for shops, restaurants, a bakery, a gym and a pharmacy, connecting the building to daily neighbourhood life. Around them are 2,600 m² of new public space, including a square facing the Seine and two footpaths that cut through the block and offer views of a nearby cable bridge.
More than 2,000 m² of shared terraces and communal rooms are spread up through the towers at various heights. Surrounded by raw concrete and red walls, door frames and windows are painted in different colours as a code, telling residents which flat type is which and helping them find their way. Two of the towers put different kinds of housing along the same corridor, an arrangement that is rarely tried.
Sustainability
The environmental savings come first from the shape of the building and only then from its systems. The shallow plan, the large, well-placed windows and the recessed balconies cut heat gain in summer and heat loss in winter before any AC is needed. On top of that, the flats use about 20% less energy than current standards require, heating runs off a geothermal system that draws warmth from the ground, and a fifth of the concrete in the structure and façades is low-carbon. The adaptable flats should also be considered here, since a home that can be divided or extended avoids the materials a new building would need.
Project information
Architecture Company: STAR Strategies + Architecture
Lead Designer: Beatriz Ramo
Design Team: Danae Zachariaki, Efraín Pérez del Barrio, Ivan Guerrero, Geoffrey Clamour, Syeva Roest, Javier Cuartero, Bittor Arrillaga, Maria Castillo, Iris Ramas, Marc Coma
Landscape Design Company: Bernd Upmeyer / BOARD
Construction Company: Bouygues Bâtiment Île-de-France
Client: Phase 1, SADEV 94; Phase 2, SOGEPROM Réalisations
Location: Ivry-sur-Seine, Paris, France
Date: 2025
