Farmhouse in Lurais

6907
Last modified by the author on 11/05/2020 - 12:12

Renovation

  • Building Type : Isolated or semi-detached house
  • Construction Year : 1700
  • Delivery year : 2017
  • Address 1 - street : Le bourg 36220 LURAIS, France
  • Climate zone : [Cfb] Marine Mild Winter, warm summer, no dry season.

  • Net Floor Area : 75 m2
  • Construction/refurbishment cost : 137 000 €
  • Number of Dwelling : 1 Dwelling
  • Cost/m2 : 1826.67 €/m2
  • Primary energy need
    kWhep/m2.an
    (Calculation method : )

This small farmhouse (late eighteenth), although it is modest by its architecture, occupies an important place in the center of the village of Lurais. It closes the public space located between the inscribed church MH, the Town Hall, classified patrimony of the twentieth century and the castle of Lurais which dominates the Creuse. This has determined the municipality to undertake the heavy rehabilitation of this rental housing.

This could be done in the framework of the experiment "Low Consumption Heritage" of the Regional Natural Park of Brenne because this house presents the typology traditional of the rural houses of the territory and the solutions of rehabilitation biosourced experimented here will be able apply to a large number of private homes.

This house was built on the principle of the farmhouse, that is to say several modules of 4.5 m wide (corresponding to the length of wood available for the joist), contiguous to walls of 0.45 to 0.55 depending from the time of construction. Even though it was still living a year ago, it had been without long-term maintenance.
The choice was made of biosourced materials that are or can be produced locally (hemp and straw), in order to propose the development of short circuit solutions for the general public.
Hemp lime renders in thermal improvement respond particularly well to the question of the airtightness of the walls. Although less efficient in terms of insulation, they improve thermal comfort and maintain summer comfort-high quality of the old building.


Sustainable development approach of the project owner

Project based on biosourced materials that are or can be produced locally (hemp and straw), in order to propose the development of short circuit solutions to the general public.

Architectural description

This house was built on the principle of the farmhouse, that is to say several modules of 4.5 m wide (corresponding to the length of wood available for the joist), contiguous to walls of 0.45 to 0.55 depending from the time of construction. The roof had to be redone completely identical, including the frame, with removal and rests of the dormers of origin. A gable wall, strongly pushed by the frame, was cut down and rebuilt. The first wall of roof was cut down to create a large living room and a bedroom. The chimneys have been demolished and the bathroom space -WC has been enlarged to meet disabled accessibility standards. This allows to have a bathroom lit by a direct day. The outdoor area is also equipped for disabled accessibility. However, the dimensions of the doors of the house have not been modified to maintain the original facade

See more details about this project

 http://www.envirobatcentre.com/envirotheque/observatoire-des-realisations/fiches-envirobat/biosource/longere-lurais-277.html?article=2971
 https://www.parc-naturel-brenne.fr/telechargements/category/25-patrimoine-culturel-architecture-paysages

Contractor

Construction Manager

Stakeholders



    Company

    Entreprise Kavinski

    02 54 37 32 86




Energy consumption

    Need for heating: 50 to 60 kWhep / m2.an

  • 489,00 kWhep/m2.an

Real final energy consumption

    56,00 kWhef/m2.an

Envelope performance

    - Low floor: R = 2.5 m2.K / W
    Completely filed to make a concrete slab hemp lime 25 cm thick. The finish is done traditionally with re-used terracotta tiles laid on a natural lime mortar screed.

    - Roofing: The frame was deposited and rebuilt in oak in a traditional way. The roof was made of flat tiles for re-use. Supply and installation of a screen of under roof with contre-liteaunage.The dormers are rested with the identical with realization of a valley crossed in tiles. In the attic, a lime flashing is placed on the periphery to achieve a mechanical seal. On the whole surface of the high floor: Installation of a steam brake membrane SD = 12 glued on the flashing on the periphery of the building and taped between them to ensure the airtightness.Above this membrane poses d insulation in straw bales R = 7.1 m².K / W. Residual spaces are filled with straw or wood wool. Realization of a rodent protection on the thermal insulation.

    SAS: Bathroom and laundry: insulating wall in wood frame including (Ext to int):
    -Woodwood side woodwork + 12mm OSB bracing,
    -Wooden structure of 145 mm insulated between uprights by 140 mm of wood wool (λ = 0.038 W / m.K-structure on a basement wall, waterproof resi-binding),
    -Fresh steam
    -Woodenwood Grab + Fermacell Plates
    -Management of the airtightness of the connection between wood frame, ceiling and penetrations of joists.

    Peripheral walls: The walls are built of sandstone limestone mounted on sand (sandy clay soil which serves as a binder).
    West gable wall: Demolished and rebuilt on foundation in BA, external buried waterproofing and waterproof arase. Wall masonry made of bricks (Type Bio'Bric -R> 1,45m².K / W). Projected hemp lime rendering (λ ≤ 0,07 W / K.m) to the machine with a thickness of 15 cm + 2 cm of finishing.
    North wall (without opening): Plaster lime hemp sprayed with the machine of a thickness of 15cm + 2 cm of finish.
    South wall: Plaster hemp lime projected thickness of 5cm + 2cm of finish.
    East Sprocket (laundry side): Stone plaster facing the room side. Extension insulation wood frame + wood wool

    Joinery and shutters full

  • 0,55

Systems

    • Electric heater
    • Wood boiler
    • Other hot water system
    • No cooling system
    • Humidity sensitive Air Handling Unit (Hygro B
    • No renewable energy systems

    Heating and Emitters: Pellet stove (1 to 4.5 KW 90% efficiency) & electric radiator dry towel for the bathroom (Power 500 W).

    Hot Water Sanitary: Thermo-dynamic water heater, vertical, on base floor insulation of 30 cm, (200 liters -COP> 3) Air intake in the attic (temperate, or even preheated during hot periods).

    Ventilation: Simple humidity-controlled flow type B-low extractor con-summation. The unit and the ducts are placed in the attic. The rejection of the air is channeled at the outlet by the conduit paired with that of the chimney

Urban environment

    This small farmhouse (late eighteenth), although modest by its architecture, occupies an important place in the center of the town of Lurais. It closes the public space located between the inscribed church MH, the Town Hall, classified patrimony of the twentieth century and the castle of Lurais which dominates the Creuse.

Product

    Bio'Bric

    https://biobric.com

     https://biobric.com

    Structural work / Structure - Masonry - Facade

Construction and exploitation costs

  • 137 000

Indoor Air quality

    The measurement of the air quality was planned before occupying the dwelling.

Comfort

    The instrumentation set up after work allows:

    • Measure heat efficiency gains in consumption and comfort.
    • Check the drying and moisture management of hemp lime renders

Life Cycle Analysis

    Materials implemented

    • Structure: Walls of limestone rubble and bone-wood
    • Insulation: Wood wool / Straw boots
    • Thermal correction: Hemp lime
    • Exterior coating: Lime plaster

    Quantity Bio-based materials

    • Total project area: 75 m² (S.Plancher)
    • Total mass of MBS implemented: 165 Kg / m²
    • Mass non-wood work and layout: 91 Kg / m²

    Complementary elements

    • Straw from local agriculture.
    • Reuse of materials from deconstruction.

Reasons for participating in the competition(s)

  • Rénovation patrimoniale biosourcée
  • Respect du bâti ancien
  • Performances énergétiques de premier ordre

Building candidate in the category

Energy & Temperate Climates

Energy & Temperate Climates

Users' Choice

Users' Choice

Green Solutions Awards 2019 - Buildings
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Emmanuel d'Envirobat Centre


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