Hoche Residence - Bois d'Arcy

1839 Last modified by the author on 18/07/2022 - 09:33


  • Building Type : Collective housing > 50m
  • Construction Year : 1966
  • Delivery year : 2022
  • Address 1 - street : 15-21 rue Toulouse Lautrec 78390 BOIS D'ARCY, France
  • Climate zone : [Cfb] Marine Mild Winter, warm summer, no dry season.

  • Net Floor Area : 7 200 m2
  • Construction/refurbishment cost : 1 700 000 €
  • Number of Dwelling : 125 Dwelling
  • Cost/m2 : 236.11 €/m2
  • Primary energy need
    215 kWhep/m2.an
    (Calculation method : RT 2012 )
Energy consumption
Economical buildingBuilding
< 50A
51 à 90B
91 à 150C
151 à 230D
231 à 330E
331 à 450F
> 450G
Energy-intensive building

This 1966 condominium, comprising 6 buildings for a total of 120 R+4 apartments at most, first undertook a thermal audit. Noting an aging of its heritage, it then decides to engage in project management studies.

The condominium is the subject of a facelift with rock wool and polystyrene insulation. The undersides of the buildings on the piling parts are insulated.

A mechanical ventilation VMC has been installed on the roof with new extraction vents in the apartments.

The balcony railings have been changed. The stairwells are lit by windows which have been renewed. The entrance halls are also renovated and the doors changed.


The renovation of the condominium including the exterior insulation of the buildings, it was possible to finance this work with a loan at zero interest. Work excluding energy savings could be financed by a conventional collective loan

50 co-owners have chosen to subscribe to it. About 36% of the total budget was borrowed by the collective loans offered by the condominium.

During the study, the financial engineering will lead to modifying the work plan to trigger the Anah subsidies for the most modest while removing high and non-priority work items.

Project timeline

Stage title Start date End date
Thermal Audit Fall 2015 Spring 2016
Project management studies Fall 2016 Summer 2017
Project management studies
Heating ventilation
Summer 2017 Winter 2018
Financial engineering April 2017 March 2018
Voting of works   March 2018
Works March 2018 2022


Photo credit



    Foncia les 2 ruisseaux

Construction Manager

    Pierre Lefranc Architecte (Lefranc Anjuere)


    Environmental consultancy


    Financial engineering


    Giffard ETC

    Heating ventilation





    MPP Norba (Tryba)



    EMC Airtec


Energy consumption

  • 215,00 kWhep/m2.an
  • RT 2012

  • 288,00 kWhep/m2.an


    • Gas boiler
    • Gas boiler
    • No cooling system
    • Humidity sensitive Air Handling Unit (Hygro B
    • No renewable energy systems

Urban environment

    This residence built in the 1968s is part of Bois d'Arcy, a pleasantly wooded commune not far from Versailles and close to the main traffic axes created in the great period of post-war urban development. A commercial area nearby provides all the necessary services.

Construction and exploitation costs

  • 1 700 000
  • 340 000
  • Average cost per accommodation: 13,600 euros
    Medium budget :
    - T2: 12,000 euros
    - T3: €15,000
    - T4: 17,000 euros

    The project has benefited from EEC aid for an amount of approximately 650 euros per household.
    The project is eligible for the tax credit: estimate around 2,000 euros per household.
    The project is eligible for aid from Anah: around 30 beneficiaries (aid between 6,000 and 11,000 euros per household)

    Breakdown of costs by item:
    - Renovation with insulation of facades: 990,000 euros
    - VMC Hygro B: 116,000 euros
    - Railing: 19,000 euros
    - Hall entrance doors: 40,000 euros
    - Canopies of the stairwells: 23,000 euros
    - Boiler room improvement: 57,000 euros

Reasons for participating in the competition(s)

An energy renovation that has improved the thermal comfort of the inhabitants of this 1960s condominium. To make the project accessible to all inhabitants, financial engineering has been undertaken. The financial aid and loans available have thus been identified and made it possible to finance part of the work.

Trophées des Copros des Yvelines
 building housing renovation energy Yvelines Copro Trophies Copro renovation

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Author of the page
Laurent Demas

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