4 passive social housing in straw wood

  • Building Type : Collective housing < 50m
  • Construction Year : 2018
  • Delivery year : 2018
  • Address 1 - street : 4 rue de la Meurthe 88230 PLAINFAING, France
  • Climate zone : [Cbc] Mild, dry winter, warm and wet summer.

  • Net Floor Area : 317 m2
  • Construction/refurbishment cost : 487 000 €
  • Cost/m2 : 1536.28 €/m2

Certifications :

  • Primary energy need :
    45 kWhep/m2.an
    (Calculation method : RT 2012 )
Energy consumption
Economical buildingBuilding
< 50A
A
51 à 90B
B
91 à 150C
C
151 à 230D
D
231 à 330E
E
331 à 450F
F
> 450G
G
Energy-intensive building

This building was awarded the Low Carbon Prize of the Green Solutions Awards 2020-21, at both the national and international levels.

This project of 4 collective social housing is located on the edge of the center of the Vosges commune of Plainfaing on a small plot of approximately 1000m².

Composed of a compact main building (in R + 1 without basement) oriented to the South and a small annex building regrouping carport and individual 2-wheeler rooms. The position of the latter makes it possible to limit the impact of vehicles.

A simple and pragmatic design methodology
1. Sobriety: Reduction to a minimum of all needs (bioclimatism, compactness, optimization of the plan and technical rooms)
2. Efficiency: Perfectly continuous and hyper-insulated structure and envelope, absolute airtightness , certified high efficiency double flow ventilation, heat recovery from gray water
3. Renewable: use of renewable energies and for the construction of structural materials at 90% by volume plant fiber

Low carbon as a leitmotif

These social housing units are entirely built in wood structure. They are and insulated in straw (walls) and cellulose (ceiling). 90% of the materials by volume are derived from plant fibers. This choice also makes it possible to provide an excellent phase shift for summer comfort.

The simplicity of the plan allows centralization and pooling of energy systems.

Collective heating and DHW production are provided by an extract air heat pump. In addition, each accommodation is equipped with an individual log stove (the outdoor 2-wheel room is largely sized and ventilated to be able to also store its wood)

The accommodation is ventilated by a collective double-flow CMV which serves as a heating vector ( no other heat emitter)

A heat recovery system from gray water in showers also reduces energy requirements.

Thus, these 4 biosourced dwellings, using renewable energies, integrated in their environment but also in their time, offer extremely low energy charges to tenants: 15 € / month / housing for 100% heating + DHW + ventilation + maintenance!

A vernacular and bioclimatic architectural gesture

The building presents a sober architecture underlined by a fine treatment of the constructive details. It is south facing and has bioclimatic outskirts. The treatment of the surrounding biodiversity makes it possible to integrate it perfectly into the landscape.

The main monolithic volume, which is reminiscent of that of the Vosges farm buildings, is covered with a "skin" made of terracotta. This "living" cladding resulting from the progressive mixture of three models of tiles (matt black and black and glazed gray) evokes the traditional wood essis and plays with its reflections to blend into its pastoral setting.

The wooden cladding used only in protected parts of the facades reveals the essence of the construction and is intended as an invitation to come and discover the soul of homes.

This building was awarded the 2019 Envirobat Grand Est Prize, category new collective housing.

Sustainable development approach of the project owner

This project is based on the negawatt philosophy and methodology:

1 / Sobriety: Reduction to a minimum of all needs (bioclimatism, compactness, optimization of the plan and technical rooms)
2 / Efficiency: Perfectly continuous and hyper-insulated structure and envelope, absolute airtightness, certified high efficiency double flow ventilation, heat recovery from gray water
3 / Renewable: use of renewable energies and, for construction, structural materials containing 90% by volume of plant fiber

Architectural description

Composed of a compact main building (in R + 1) without basement) oriented towards the South and of a small annex building regrouping car-port and individual 2-wheelers premises. The position of the latter makes it possible to limit the impact of vehicles.

It presents a sober architecture, underlined by a fine treatment of the constructive details. The main monolithic volume, which is reminiscent of that of the Vosges farm buildings, is covered with a "skin" made of terracotta. This facetiously faceted cladding resulting from the degraded mix of three models of tiles (black and glazed gray and matt and matt black) evokes traditional wood essis and plays with its reflections to blend into its pastoral setting.
The wooden cladding used only in protected parts of the facades, reveals the essence of the construction and is intended as an invitation to come and discover the soul of homes.
The building is entirely constructed in a wooden structure and insulated with straw for the walls and cellulose for the ceiling.

Photo credit

Thomas Devard and ASP Architecture

Contractor

    SA HLM Le Toit Vosgien

Construction Manager

    ASP Architecture

Stakeholders

    Thermal consultancy agency

    Terranergie

    https://www.construction21.org/france/company/fr/terranergie-bureau-detudes.html

Energy consumption

  • 45,00 kWhep/m2.an
  • 70,00 kWhep/m2.an
  • RT 2012

    Heating 14kWh / m² of log wood DHW 12kWh / m² of renewable electricity (collective CET R290) CMV Double Flux 3kWh / m² Household electrical appliances: 60kWh / m²

Real final energy consumption

    117,00 kWhef/m2.an

Envelope performance

    n50

  • 0,60

Systems

    • Others
    • Wood boiler
    • Heat pump
    • No cooling system
    • Double flow heat exchanger
    • Wood boiler
    • Heat pump

    The simplicity of the plan allows centralization and pooling of energy systems.
    Collective heating and DHW production are provided by an extract air heat pump. In addition, each accommodation is equipped with an individual log stove (the outdoor 2-wheel room is largely sized and ventilated to be able to also store its wood).
    The accommodations are ventilated by a collective double-flow CMV which serves as a heating vector (no other heat emitter).
    A heat recovery system from gray water from showers also reduces energy needs (provides 25% of the DHW).

Biodiversity approach

  • 1 056,00 m2
  • The site is located near the city center, 200m from the Town Hall and therefore public transport.

    Study of solar masks so as not to create shadows on neighboring plots.
    Adaptation to a land with little influence while giving the project a bioclimatic orientation towards the south.
    Minimization of non-vegetated surfaces.

    All the outdoor facilities (parking, pedestrian roads, private terraces, etc.) and the 2 ground floor accommodation are accessible for people with reduced mobility.

Product

    Straw

    Passiv Home

    Gros œuvre / Charpente, couverture, étanchéité

    ...

Energy bill

  • 150,00

Indoor Air quality

    VMC Double flow at 0.5Vol / h 24h / 24
    Any VOC class A + finishing product

Comfort

    VMC Double flow at 0.5Vol / h 24h / 24
    Any VOC class A + finishing product

    <600ppm

    Taux de surchauffe >25° < 5%

    idem études

    According

    >2,5% sur 80% des pièces ayant accès

GHG emissions

  • 3,00 KgCO2/m2/an
  • All use via Phpp and ADEME emission factor

  • 700,00 KgCO2 /m2
  • 50,00 année(s)
  • 850,00 KgCO2 /m2
  • E-Licco / ADEME

Life Cycle Analysis

    The wood and straw used are renewable, local and minimally processed materials.

    The use of healthy materials also makes it possible one day to envisage a simple and sober deconstruction.

    More information on embodied energy in the PDF doc inserted in description.

Reasons for participating in the competition(s)

Sustainable and local materials:
The structure of the building is composed of 90% local and little transformed plant fibers (wood and straw). These materials allow for simple and sober deconstruction, and are recyclable. For the passive, the bioclimatic design emphasizes the envelope which is a priority and will not change for 60 years unlike the energy systems. 


Energy performance:
The structure and envelope allow insulation and sealing. The installation of a double flow ventilation serves as a vector for heating based on an individual log stove. Each dwelling has in addition an airy 2-wheeled room provided to store wood. The plan of the building allows the centralization of energy systems, and heat is also recovered from the gray water of the showers. 


Social issue:
The goal was also to offer extremely low energy charges to the tenants who are low-income families: 15€/month/unit. This reduction in charges allows for the social integration of families and an increase in their purchasing power. The building, which is in keeping with the Vosges architecture of its region, is 200m from the town hall and public transportation in.

Building candidate in the category

Bas Carbone

Bas Carbone

Green Solutions Awards 2020-2021 / France

 building
 low carbon
 GSA
 wood
 straw
 materials
 energy performance
 biobased
 bioclimatism

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