Photo credit: Benoit Lavat

Located in Tours in the West of France, this projects consists of the radical transformation of a Postal Sorting Office that was built in the 1980’s, into a multi-purpose, energy positive building containing a medical centre, offices, apartments and individual houses constructed on the roof.

The original, concrete framed building was fully renovated and extended upwards using prefabricated timber structures.  The objective was to create a lighthouse project demonstrating the feasibility of going beyond 100% energy savings by creating an energy positive building.  This was achieved through the integration of bio-climatic design principles with a highly performing building envelope linked to advanced and regularly commissioned heating, cooling and energy-generating systems.


Principle Characteristics of the Renovation Works:

Ownership type: Private
Year of construction: 1981
Renovation completed: 2014
Floor area after works: 13,000 m² (of which 6,500 m² dwellings)
Structure: Reinforced concrete with highly insulated timber-framed walling elements and roof structures
Heating and energy: 100% renewable energy sources including photovoltaics, solar thermal and ground sourced heat pumps.  Heat recovery ventilation system and energy balancing using a water tank in the basement in the site of the adjective heating system.
Energy performance: Greater than 100% energy efficient as the buildings produces more energy in a year than it consumes
Cost of works: €17m (equates to €1,300 per m²)
Architect: Boille et Associes, Tours
Technical consultants: Egis Batiments Centre-Ouest

EGIS post on the La Nef renovation project in Tours, including access to a report on same:

EGIS blogpost written by Jerome Diot on the renovation turning the building into Tours’ first energy positive building:

Blogpost on the project from Au Coeur de Limmo: