The first Energy Performance Contract (CPE) in the social housing sector, applied in 2010 by LogiRep, a subsidiary of the Polylogis group, and carried out by a consortium led by Bouygues
Bâtiment Ile-de-France subsidiary Brézillon, has reported positive results. The social housing development in question, La Saussaie, is located in Vitry-sur-Seine, in the southern suburbs of Paris. 

Following the renovation works and a year of heating, the apartment complex is now classed in the top energy-efficiency category (A) and is achieving more than 50% energy savings.   

Thanks to their active participation in this ambitious project, tenants now benefit from lower energy costs and a higher level of comfort. 

Innovation in the housing sector 

In 2010, seeking to meet challenges set by the French "Grenelle" round-table conference on the environment, LogiRep, a subsidiary of Polylogis, invited a consortium1 led by Brézillon to design and implement an Energy Performance Contract (CPE), a novel type of energy renovation programme, to be applied to the La Saussaie social housing development in Vitry-sur-Seine, in the Paris suburbs. 

This totally original contract stipulates: 

- guaranteed results, the consortium committing itself to maintaining the energy equipment for four years (until the end of 2016) and guaranteeing energy savings on heating and hot water of 40% after the works, 

- a financial contribution to the energy-saving works from the tenants though an additional charge levied with the rent, 

- the principle of dividing the anticipated cost savings between landlord and tenants. 

This programme was the first Energy Performance Contract applied to social housing. 

Consumption halved in the first year 

The apartment complex was built in 1965, before the first oil crisis, and had never been renovated. The refurbishment works carried out by Brézillon and Cogemex lasted 18 months, and included:
  
•    Works to regulate and optimise heating networks, 

•    Installation of solar panels, allowing a 30% saving on the cost of producing hot water, 

•    Interior thermal insulation, 

•    Replacement of external doors and windows, 

•    Insulation of under-surfaces and terraces, 

•    Creation of a green roof, 

•    Refurbishment of communal areas,

•    Improved comfort in 231 units (electricity and plumbing),

•    Installation of humidity-sensitive ventilation, 

•    Conversion of 6 units to create homes accessible to people with disabilities.

As a result of this programme of works, the apartment complex has raised its classification from energy efficiency category E to the highest level, A. 

Following the first year of heating (October 2012 / October 2013), the consortium has reported a 53% real saving on consumption for heating and hot water. This is reflected directly in the buildings' energy bills. At the end of the first year, the contract has resulted in more than €40 of monthly savings, of which €28 is passed on directly to tenants. 

The four-year maintenance contract stipulates a battery of measurements and controls each year in order to guarantee that the commitments made by the consortium and LogiRep with regard to the tenants are fully honoured. 

Tenants at the heart of success 

In order to achieve the energy efficiency optimisation targets defined by the CPE, an awareness-raising campaign for residents was carried out. The initiative was designed with assistance from the sociologist René Bresson and a local organisation, "Ambassadors of Sustainable Development". Among its achievements: 

•    educating tenants on eco-efficient practices through information meetings, workshops and one-on-one contact, 

•    distribution of a "renovation guide" at the start of the project and a handbook of eco-friendly actions cataloguing all the steps they can take to reduce their energy consumption while maintaining a high level of comfort,

•    launching a dedicated website for the complex that allows tenants simple real-time monitoring of their individual energy consumption. 

The contract for the programme of works was worth a total of €9 million (€4 million for the energy renovation and €5 million for the interior refurbishment of the apartments). 

Daniel Biard, Chairman of the Executive Committee of the Polylogis group, said: "For almost ten years, the Polylogis group has been developing new methods intended to improve the energy performance of its housing stock. We go beyond the strict regulatory requirements. This pioneer project is a perfect illustration of a success for one of our teams. We are proud of the results achieved in Vitry. And not only on a technical level: the CPE has helped sustain the financial solvency of our tenants by making them less vulnerable to energy price rises." 

Jean-Christophe Perraud, Executive Vice President of Bouygues Bâtiment Ile-de-France, said: "This first CPE in the social housing sector in France proves that it is possible to significantly improve the energy performance of buildings and the quality of life of their inhabitants through concrete, affordable measures. The success of this operation confirms the relevance of Bouygues Construction's global offer." 

¹ The consortium consists of Brézillon (lead company), the architects Lair and Roynette, CET (technical consulting engineers) and Cogemex (maintenance)