Case Study: LogiRep pilot Résidence Saussaie - SHELTER Project

Short Description

Energy renovation and urban renewal of 3 apartment blocks from 1966. First energy performance contract (CPE) for social housing in France for designing, modernising and extending a social housing development in Vitry-sur-Seine (southern suburbs of Paris) containing 231 flats, and for maintenance of the energy equipment system for four years. The project will guarantee 40% reduction in real energy consumption and will cut greenhouse gas emissions by a factor of 4.

Worth 9 million euros (4 million euros of energy renovation works and 5 million euros of internal renovation of the accommodation), the project qualifies for optimised funding through State financial mechanisms to aid social housing, specifically the decree concerning the share-out of energy savings. Works will be launched early in 2011, and are scheduled to last 24 months.

Key Elements

Certification

Objective of French BBC label (240 to 104 kWhEP/m².year).
Guarantee of reaching 40% of real energy consumption reduction.
Guarantee of reducing by 4 Green House Emissions.

Asset Management

Stock conditions survey: building energy audit.
Determination of the starting point for the historical consumption.
Determination of the reference situation (MWh/year).
Selection of cost-effective and energy efficient refurbishment options.

Project Management

Integrated project delivery.
4 years maintenance.
Energy savings guaranteed by contract.
Individual consumption monitoring and follow-up through a web-page to understand the resident’s behaviour.

Work with Residents

Social workers are involved in the project to inform residents on the behaviour to be adopted in order to reach energy consumption reduction objectives. Energy consumption monitoring.

Distribution of a “green behaviour manual”, workshops, internet site for residents focused on energy performance.

Funding

Financing by the National Energy Agency (ADEME) 4%, the Municipality 4%, the Region 5%, Energy Savings certificates 7%, eco-loans 30%, land tax exemption 8%, improvement loans 37%.

Partnership Working

Integration in the design and delivery project team of a renewable energy expert, and an energy performance guarantee expert.

Thermal Insulation

External insulation of the envelope: 12cm. Insulation of the roof with 12cm of polyurethane. Thermal bridges are eliminated.

Windows and Shading

Replacement of the existing single glazing windows by double glazing panels 4/16/4 low-e with PVC window frames. Shading devices: external PVC roller shutters.

Ventilation

Natural ventilation with hygrostat.

Heating and Hot Water

Use of the already existing district heating, where 49% of the energy is biomass.
Individual monitoring of energy and water consumption.

Solar Thermal

250 m2 of solar thermal panels for Domestic Hot Water, covering 30% of the needs.

Electricity Saving Products

Low-consumption bulbs for lighting of common areas.

Environmental Design

Green roof on one of the apartment blocks.

Water Saving

Water flow regulation. 3/6 l water flusher for toilets.

Main Results

Energy Savings:
40%: from 242 kWh/m2/year to 141kWh/m2/year (real consumption) and 62 kWh/m2/year in theoretical consumption. Including this parameter in the award criteria has led to ambitious proposals from the bidders.

Costs:
9M euros, 4M energy works.

Timing:
Design phase longer, but it includes decisions that are usually taken during the construction phase. The architect estimates the design was done in half the time compared to a standard procedure.
Worksite preparation was longer but done in hidden time. The decisions taken during the design phase guarantee less problems during the construction phase and decreases the risk of work delays.

Lessons learned

Future possible improvements and replication:

Critical mass
The integrated design experience, as well as the guarantee of performance cannot be implemented in all the building stock to be renovated at Logirep. Several conditions, particularly a critical number of dwellings, are necessary to attract contractors via energy savings potential. Logirep would like to implement integrated design with guarantee of performance in smaller projects. A possibility could be grouping of smaller projects, provided that the program of works are similar and the projects are geographically close. This reduces the number of projects where grouping could be a possibility.

Real energy consumption monitoring
The follow-up of energy consumption is mainly for the use of the consortium in order to monitor the performance that is guaranteed by the contract. Logirep finds monitoring all the dwellings as it is foreseen in Vitry is excessive and too expensive for the project. Monitoring 20% of the dwellings could be enough and it will be experienced in future projects. Logirep would also like to go further in our next project and to develop smart metering in order to be able to have a mode direct influence on the tenant energy behavior. This can be asked to the contracted consortium, but also a competence to be developed in-house in order to better communicate with the tenants on energy saving issues.

High energy performance ambitions
Finally, Logirep thinks integrated design is necessary in projects with high-energy performance objectives. Reaching a nearly-zero performance after works needs a close cooperation between design and construction that can only be achieved with a single tender. Logirep will experience in 2013 a 70 dwellings building renovation to a passive standard using an integrated design procedure.

Additional Information

Contact:

Xavier Martel
LogiRep (subsidiary company of Polylogis Group) 
E-mail: martel.x@logirep.f
Phone: +33 (0)1 40 99 45 31