International audienceThe Biovallée, a large scale area of political cooperation (102 municipalities, southern France), ambitionned in 2009 to become a ‘rural Freibourg’, and get a financial support (10 M€ from the Region, 5M€ from the department of Drôme) to develop such an experimental place for high standard solutions about renewables and efficiency buildings. Local competencies with national involvment in alternative energy netwoks and national policy processes were located in the Biovallée :Enertech, an engineering office specialised in thermal simulations and involved in several pionneering experiments in efficiency buildings ; the négaWatt Institute, dedicated to training, research and engineering studies about energy efficiency solutions. The director of Enertech, involved in the Grenelle de l’Environnement in 2007, failed to promote in this arena the idea that the refurbishment of residential buildings could be a legal requirement. The Biovallée project raised for him the opportunity to test an alternative ‘market’ solution through the making of global low energy retroffitting offer for private owners. This model consists in assembling the local officers as energy advisors, with craftsmen collectives as coherent entities (38 companies) to propose energy and cost efficiency solutions, and the experts (Enertech, négaWatt) as trainers and conductors. This creates a new agency through which the private owners are empowered so as to strategically choose how to make the appropriate investment for the better energy efficiency solution. Thus, two key emerging dimensions unsually gathered are adjusted through this new sociotechnical assemblage, one of decentralisation of the housing policy, one of marketisation of the energy-efficient refurbishment issues of private housings still today neglected by the building sector