Neuilly/Levalloise and Boulogne/Issy-les-Moulineaux: new areas of attraction for the conversion of offices into housing

ORIE has updated its recycling index, first published in February 2025, to assess the potential for converting office buildings into housing by market segment. This second edition allows us to observe the evolution of feasibility conditions, one year after its initial publication. As the situation worsens, with 1,3 million people living in inadequate housing in the Île-de-France region according to figures from the Housing Foundation (December 2025), office conversion appears as one of the solutions to the crisis.

This new edition offers a municipal-level perspective, allowing for a more precise analysis of local dynamics. Among the study's main findings:

• The first ring confirms its relevance for the conversion of offices into housing.
• The Neuilly/Levallois and Boulogne/Issy areas are becoming more attractive due to the decline in the sale prices of commercial buildings.
• La Défense is losing its attractiveness in the office-to-residential transformation, due to the return of a market for tertiary tenants.
• Paris proper remains a very attractive area for the service sector and therefore not very favorable to the conversion of offices except for the 18th and 20th arrondissements where residential attractiveness is increasing.

This tool is intended to help newly elected officials respond more appropriately to housing needs, by supporting the conversion of offices in areas where the index is highest.

The territories of the inner suburbs represent the greatest potential for transformation.

The city of Clichy maintains the highest recyclability score (+0,93) in the Ile-de-France region. This performance is explained by the combination of a dynamic residential market, a relatively large volume of tertiary supply with more moderate demand, as well as a significant price difference between new housing and vacant second-hand offices, making it possible to consider economically viable conversion projects.

Several municipalities in the inner suburbs also show strong potential for transformation, particularly in the northern part of the Île-de-France region: Colombes (+0,80), Asnières-sur-Seine (+0,78), and Gennevilliers (+0,73). To the west, Saint-Cloud, Sèvres, and Suresnes also show high scores (around +0,70), as does Rueil-Malmaison (+0,63). This geographical pattern aligns with the findings of the first edition.

Paris: overall limited potential, with the exception of eastern Paris

As in the previous edition, Paris confirms a relatively limited potential for transformation. The strong performance of the commercial rental market and high office valuations make conversion projects more difficult to financially balance.

However, some districts in eastern Paris stand out, notably the 18th and 20th districts (+0,63), whose score is improving and which now rank 7th among the tertiary markets of the Île-de-France region in terms of recyclability.

Significant changes in certain major service markets

Conversely, contrary to the trends of the first edition, several major service sector markets have recorded significant progress in the rankings. This is particularly the case for Neuilly-Levallois (+0,45), which gained 24 places, and Boulogne-Issy (+0,37), which climbed 15 places.

This trend is explained by a greater supply of office space, strengthening the service sector, as well as by downward adjustments in sale prices, improving the economic viability of projects. These areas also continue to benefit from favorable residential trends.

Contrary to this trend, the La Défense business district (+0,21) recorded the sharpest decline in the ranking (-13 places) and now sits in 18th position. This shift is largely due to more favorable signs recently observed in the commercial real estate rental market, with improved take-up and a stabilizing supply.

Potential has also been identified in the south of the metropolis.

South of the metropolis, some municipalities in the first ring also present interesting recycling prospects, notably Ivry-sur-Seine (+0,65), Charenton-le-Pont (+0,61) or Gentilly (+0,57).

Conversely, the outer suburbs of Paris generally show more moderate scores. The level of office space supply there is generally more controlled and, above all, the price differences between offices and housing make it more difficult to achieve economic viability in redevelopment projects.

According to Richard Malle, university professor at CNAM and lead author of the study: “Certain areas, such as Neuilly-Levallois, Boulogne-Issy, or, conversely, La Défense, are experiencing contrasting trends in property values ​​and take-up, causing their recycling index to fluctuate compared to 2025, either upwards or downwards. Paris proper remains relatively unattractive for redevelopment projects, while generating strong interest from commercial tenants, particularly in the west-central districts. The potential for redevelopment remains particularly concentrated in the inner suburbs, in the immediate vicinity of the capital. In the context of the installation of municipal governments, these areas present an opportunity to accelerate and scale up redevelopment projects, contributing to the construction of a more sustainable, resilient, and energy-efficient city.”

Recycling index - methodology

ORIE has created an index to assess the potential for converting offices into housing in the Île-de-France region, with a scale ranging from -1 for areas where conversion is challenging to +1 for those with the best conditions. For this edition, the index covers 113 municipalities across 34 commercial markets, representing over 80% of the office stock in Île-de-France. It is based on three main weighted factors:

• Economic feasibility (40%), which assesses the economic balance of transformation operations, by analyzing the value gap between existing offices and new housing;
• The tertiary sector dynamic (30%), which measures the level of office supply in relation to the demand placed, as well as the vacancy rate;
• Residential dynamics (30%), which takes into account housing production, net migration, changes in new housing prices and accessibility by transport.

Find the study on www.orie.asso.fr

Illustrative image of the article via Depositphotos.com.