Rehabilitation of the family pension "Le Lubidet"

Last modified by the author on 11/05/2020 - 14:37

Extension + refurbishment

  • Building Type : Terraced Individual housing
  • Construction Year : 1900
  • Delivery year : 2015
  • Address 1 - street : rue du lubidet 41100 VENDôME, France
  • Climate zone : [Cfb] Marine Mild Winter, warm summer, no dry season.

  • Net Floor Area : 783 m2
  • Construction/refurbishment cost : 1 256 500 €
  • Number of Dwelling : 14 Dwelling
  • Cost/m2 : 1604.73 €/m2

Proposed by :

  • Primary energy need
    40.1 kWhep/
    (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

The existing buildings meet an old industrial town with homes that were very outdated. The whole is transformed into a boarding house intended for the reception of people in social difficulty. The facades of housing redeveloped in their original volume keep the memory of places with their southern facade in rubble and brick, while the common premises are the object of a contemporary construction with low consumption. Particular care is taken in the study of the pathways, the organization, the treatment and the framing of the views.

Built around 1900, this site has been fully renovated to accommodate housing and allow the implementation of a collective space performance and innovative. This project, combining new construction and renovation, was carried out with the aim of emphasizing the energy and environmental performance of buildings. Thus, the straw material was highlighted as well as the lime-hemp plaster or collective heating wood pellets.

The will of the actors of the project was to rehabilitate the site of this former workers' city (housing of the old stationery built in the 1900s and closed in 1970), in a family pension:

  • by keeping the identity and the memory of the site, - by implementing environmental solutions, for a better comfort of the residents,
  • by seeking a good balance between energy performance, investment and operating costs, while taking into account the specific characteristics concerning the reception of residents.

Renovation action:

  • Of the 10 existing homes, two are destroyed to open the space overlooking the new building which is a collective space.
  • The remaining 8 dwellings are redistributed to accommodate 12 duplex units and 2 DRC dwellings fully accessible to people with reduced mobility.
  • Demolition and reconstruction of the extension overlooking the street to accommodate the toilets in the DRC
  • Two wood pellet boiler rooms are installed in the attic of the two DRC housing units.

Sustainable development approach of the project owner

The choice was made to carry out an exemplary operation on the environmental plan, which was a strong will of the owner, accompanied in this will by the architect and the master builder Fluid BET. Successive adjustments were necessary to achieve this objective and to respect the budget allocated to the operation. After the study of different options, the technical choices were focused on: - A straw insulation for the new building (with an investment in studies and training, followed by a specific straw training of 5 days, made by the architect , and the development in consultation with the wood frame / straw company). Straw is a biobased material, available in close proximity without significant transportation, without excessive cost, sustainable, renewable, and thermally efficient. This choice makes it possible to treat the airtightness and to realize a strong insulation with a capacity of important phase shift, which is very appreciable in summer as in winter (which was even found during construction). - Detailed studies and proposal of Fiabitat BET fluids, in order to arrive at a relatively low operating cost to the tenants (wood pellet boilers, double flow ventilation for common premises, etc ...). For existing dwellings, a thermal correction has been provided by a 8 cm hemp lime insulation of the walls facing the outside (allows to ensure hygrometry regulation and good comfort, while keeping the existing masonry apparent )

Architectural description

A circulation gallery serves housing open to the South; it establishes the link with the common premises located in central part, while the North facade is closed. The accessible toilets consist of small protruding volumes that punctuate the northern facade wood cladding of red blood ox, on the bottom of the rubble wall. The 14 dwellings are served by the gallery on the South facade and benefit from solar gain. For common premises created in a new building, they are located in the central part with an entrance open on street and in communication with the gallery serving dwellings. The slope of the ground being quite marked, the volumetry of the building marries this relief and treats the difference of levels (movement accompanied by both the volume and the recess of roof, and by the shape of the internal staircase). The building largely open to the South allows to take advantage of solar gains while protecting itself from overheating of summer by its overflowing roof; East and West side it is open on outdoor terraces protected by a wide roof overhang, to create spaces conducive to meetings and exchanges between residents who need to renew social ties. On the roof of the common building, the recess between the two parts of roofs allows to provide a high complementary lighting. The different volumes benefit from excellent, well-distributed natural lighting that contributes to the comfort of the premises. On the principal axis of circulation of the building: North-South axis, strongly affirmed, visual breakthroughs are provided and answer each other all along the axis of circulation, (glazed slit North on street, paved glass of the airlock, skydome on circulation and staircase, vertical frame on entrance of the common room). Accessibility has been thought through in detail (with in particular the complete removal of thresholds on 2T2 entrances and access to common East and West terraces).

See more details about this project


Energy consumption

  • 40,10 kWhep/
  • RT 2012

    The consumptions quoted above refer to the "built" part of the building knowing that no standard calculation has been made.

Envelope performance

    For the new part: Wooden frame boxes with I beams, outdoor rain panel made of wood fiber, panel
    internal bracing, isolated in straw bales, (prefabricated caissons in the workshop), arched roof with I-beams,
    isolated in straw bales laid on site and complementary glulam beams according to the staves.
    For the renovated part: hemp lime plaster on the walls and timber / straw frame on the roof.


  • 2,42
  • Building airtightness The final tests gave the following results: Rehabilitation: Q4 = 0.64 m3 / m² / h -n50 = 3.32 vol / h Nine: Q4 = 0.53 m3 / m² / h - n50 = 1.51 vol / h

More information

Part rehabilitated (Housing):  - Conventional consumption: 155 kWh / m².an  - Of which heating: 97 kWh / m².an New part (Reception building):  - Conventional consumption: 103 kWh / m².an  - Of which heating: 20.5 kWh / m².an


    • Water radiator
    • Wood boiler
    • Individual electric boiler
    • Wood boiler
    • No cooling system
    • Single flow
    • compensated Air Handling Unit
    • Double flow heat exchanger
    • Wood boiler

    The two wood pellet boilers of 12kW are relayed by low temperature radiators. The overall regulation is by housing with thermostatic valves per room. The ducts are made in isolated volumes.

    One of the wood boilers ensures the production of DHW as well as additional heating.

Urban environment

  • 783,00 m2
  • The building is located near agricultural plots but has some shops nearby as well as a shopping center. It is also close enough to the city center of Vendome. Located on the edge of a busy street, but with a narrow sidewalk and facing a hill, the whole was "turned over" so that the accesses are done South side formerly garden, thus opening large collective spaces and a view on A non-constructible meadow.The original style of the workers' buildings has been preserved and they continue to "respond" stylistically to the premises of the old paper mill which are a hundred meters on the banks of the Loir. These, now renovated welcome shops and are part of different industrial groups of the same period spread throughout the city of Vendome.The immediate area of the center of Lubidet consists of old houses or pavilions of the immediate after the war. The bias of keeping the style was logical.


    Box of straw


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    The caissons (37.2 cm) are to be filled directly on site because the shape of the roof does not allow prefabrication.
    In addition these boxes are delivered closed on the site.

    The initial project did not involve bio-based materials and was based on a classic construction method. The proposal to use bio-sourced materials was made by the thermal design office and adopted very quickly. The project manager as well as the companies did not know this constructive mode and this generated some difficulties (technical descriptions, need for the architect to follow a formation to be assured, ...)

Construction and exploitation costs

  • 1 256 500
  • Cost of the new operation: € 815,000 excluding tax
    Cost of the rehabilitation operation: 441 500 € HT


    In addition to the use of biobased materials mentioned above, particular care has been taken in the new common room, which enjoys high energy performance, enabling residents to meet in a comfortable place. The VMC double flux is equipped with a CO2 sensor. Moreover, the concept of comfort for this type of structure is a little different from a traditional habitat. Social contact is an integral part of comfort. Building a comfortable, well-oriented walkway leading to homes on the south side, encourages meetings between people. It brings, as the comfortable common room, a space of "comfort" or social reintegration to people in difficulty. The choice was also made to stay on traditional solutions in housing regarding ventilation, manual opening or the presence of small hot water balloons. Combined with the renovation of the old building, this offers a very good comfort, while limiting the cost of maintenance and repairs in case of damage. The choice to promote manual gestures for ventilation in the private areas is also an interesting bias, knowing that the public welcomed requires some tenants to get back to the reality of everyday life and its small gestures. To support the residents in the management, in complete autonomy of their home, acts of their daily life and support them in the expression within a group, a professional team is present and occupies part of this building.

Life Cycle Analysis

    Wood, straw, lime plaster, hemp plaster

Reasons for participating in the competition(s)

The approach to the Lubidet project is based on a compromise between energy performance, respect for heritage and the economic constraints of construction and maintenance .

Also aimed at vulnerable people, this housing complex has been renovated in order to promote "socialization" and meetings. The central houses have been razed to allow the establishment of an efficient and innovative collective space, while a circulation gallery serves housing on the southern side. Accessibility has been thought through in detail (with in particular the complete removal of thresholds on 2T2 entrances and access to common East and West terraces). The comfort sought is different from a traditional, but real, residential building.

The architectural aspect of the existing facades has been preserved, limiting the thermal performance of the one to the south. Nevertheless, solutions have been found (lime / hemp plaster) to reduce the cold wall sensation which directly impacts on the sensation of thermal comfort and therefore of energy consumption.

Finally, the choice has been made to give priority to wood and biobased materials for a better comfort of residents with the use of wood / straw boxes, wood wool (rain cover), laminated wood and coated lime / hemp .


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Emmanuel d'Envirobat Centre

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