Rehabilitation of the Mistral Towers in Grenoble: urban and social renovation
Interview with Gilles Billion, head of the “rehabilitation service”, who discusses the urban renewal of this neighbourhood in difficulty.
“Actis has been a social lessor involved in the energy transition for nearly 10 years*. We have rehabilitated or are rehabilitating more than 1,000 homes at BBC level, resulting in a significant reduction in charges for our tenants. The results of thermal rehabilitation monitoring confirm a 50% reduction in consumption on average and equivalent to those of new housing.”

Copyright: Actis
3 towers, 200 housing units: a major project
“Energy performance work includes the complete insulation of buildings, the replacement of joineries and a number of interior works. Rehabilitation takes place on an occupied site.
Like other projects, the rehabilitation of the Mistral Towers is part of an urban renewal strategy, so we go beyond “traditional” interventions since we are also planning:
- habitat diversification
- the development of economic activity and vocational training
- the installation of new equipment and unifying businesses
- the complete requalification of the halls and building surroundings

Copyright: Actis
The objective is to open up the district located in a Sensitive Urban Zone, to accompany the positive occupation of public space and thus to dry up the parallel drug economy for more calm and security. We want to break with the social image of the neighbourhood by proposing a purer aesthetic.
For this project, we chose to call on a general contractor rather than to solicit different professionals for several reasons:
- a single interlocutor who coordinates the work and has a global vision of the project
- skills, know-how and reliability of this company to guarantee the quality of the works but also the speed of the interventions, the works being done in occupied site
- avoid any kind of waiting in case of failure of certain companies”
The place of tenants in energy renovation
“Communication and information to tenants is a key element in facilitating acceptance of these major projects. We have put in place a number of tools such as a model home, an exhibition and a film to popularize the work and communicate the energy performance objectives. A website has also been created to give tenants a voice, and a courtesy accommodation is available if they wish to be quiet during interventions in their accommodation.

Copyright: Actis
Rehabilitations entail changes in uses and behaviour, so it is important to involve tenants from the outset. We therefore work closely with leading tenants, and the residents, through meetings and working groups, contribute to the development of their neighbourhoods.”
More info :
- Video (in french-at 5’59)
- Actis’ website
- Grenoble Alpes-Métropole’s website
*A commitment that has brought Actis several awards: Solar Decathlon Award 2014, Eco-responsible Trophy 2016, Sustainable Housing Award 2017 and Regional Wood Construction Award 2017.