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Habitat Social Positif (HSP): construction and user management of 2 positive energy houses

Highlighted Case June 2016
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The Habitat Social Positif - HSP (Positive Social Housing project), which is comprised of two row houses T3 and T4, forms part of a sustainable development project which has brought together various sectors on different levels:  the regional government of Languedoc Roussillon, the municipiality of Castelnaudary who directly involved the lycée Andréossy (technical school for the building trade), the social landlord Habitat Audois as well as a local construction manufacturer (TERREAL).

This project was also used for the practical support for research conducted in 2015 by a PhD student at the Université Toulouse - Jean Jaurès, Centre d'Étude et de Recherche Travail, Organisation, Pouvoir (CERTOP). The research was aimed at understanding the influence of occupant behavior on the performance of homes in order to work on supporting change management. That way, these positive energy buildings stay positive even with their inhabitants, and without coercion, to really meet the challenge of energy sobriety.

The 2 dwellings have been built in the eco-district Vallons des Griffoul in Castelnaudary with locally manufactured sustainable building materials which respect the principles of bioclimatic architecture in the district. They consume less energy than they produce, so their energy performance goes beyond the French Standard RT2012, labeled with the highest certifications Bepos Effinergie 2013 and Effinergie +.


The objectives were as such;


To design and construct two positive energy houses which are:

  • economically attainable
  • use simple reliable and robust building material which is also locally sourced
  • comfortable in all seasons (especially in warmer periods)
  • accesible for people with disabilities
  • respectful of its environment

also equally important;


To understand the influence of occupant behavior on the performance of the positive energy house in order to work on supporting each sector management (constructor, owner and tenant) for clarifying issues like renewable energy compensation, energy efficiency, etc.

These issues will be addressed by:

-    Professional training (le Lycée Andréossy de Castelnaudary),
-    Research and development (Research Center TERREAL),
-    Contribution on sociology of energy (CERTOP laboratory in Toulouse).





36 rue Georges Clémenceau, 11400 Castelnaudary (Languedoc Roussillon, France)



Project team


Initiators of the HSP project:

Manufacturer and project management: TERREAL

Owner: Habitat Audois

Environmental consultant: Ville de Castelnaudary

Constructor: Lycée Andréossy de Castelnaudary (Les Provinciales)


Architecture design: AEAA

Thermal consultant: CITE Vergé

Certification: CEQUIAMI

Social Housing Management: CERTOP



Time schedule


Design: n.d.

Construction: April – November 2013

Delivery: December 2013


First monitoring test: January – June 2014



Building use and area


T3 and T4 are two row, ground floor, single-family houses. Each dwelling has inside parking (garage). The houses are also used as study cases for visits arranged by the project initiators.


Plot Area: 500 m2


Total Usable Floor Area: 89,70 m2 (T3) and 99,89 m2 (T4)

Total Conditioned Area: 75,15 m2 (T3) and 85,88 m2 (T4)



Construction costs


Global construction cost (includes building fees but excludes parking, basement, urban sewerage and energy networks): 104.949 € (T3) and 134.755 € (T4).


Global cost per m2: 1.179 €/m2 (T3) and 1.334 €/m2 (T4)


Renewable energy systems cost: 11.800 € (T3) and n.d. (T4)


Project funded by le Région Languedoc Reussillon, ERDF, ADEME and Ville de Castelnaudary.




Energy performance


U-Value average: 0,28 W/m2.K (T3) and 0,34 W/m2.K (T4)


External walls:

T3  Wall masonry type A 20 cm Calibric Terreal + stucco + 11.3 cm of insulation = 0,214 W/m2.K

T4  Brick BMI isolated monolith Terreal + coating + ext plasterboard = 0,268 W/m2.K


Internal walls: Partition placbric Terreal + coating + 9,3 cm of insulation = 0.309 W/m2.K


Floors: Concrete screed + isochape + compression slab + insulation = 0.130 W/m2.K

Ceiling: plasterboard + 36 cm of blown wool insulation= 0.154 W/m2.K


More information:


Air Tightness Value: 0,36 (T3) and 0,25 (T4)



Energy consumption


Primary energy need: 41,30 kWh PE/m2.year (T3) and 34,50 kWh PE/m2.year (T4)

Primary energy need for standard building: 62,60 kWh PE/m2.year (T3) and 60,00 kWh PE/m2.year (T4)

Final Energy: 53,17 kWh FE/m2.year (T3) and 55,74 kWh FE/m2.year (T4)

Calculation method: RT 2012


Renewable PV Production: 123,1 kWh/m2.year (158,40 % T3) and 129 kWh/m2.year (340,00 % T4)


Real final energy consumption/m2 (2014): 56,39 kWh FE/m2.year (T3) and 71.83 kWh FE/m2.year (T4)


More information: Heating energy consumption was higher than expected in the thermal study. This is essentially because room temperature was above 19 ° C and the inhabitants were seeking comfort closer to 21-22 ° C. However, the specific consumption is well below the forecast which makes this home a truly positive energy housing regarding all consumption: those of the building and those of occupants.


GHG in use: 1,00 KgCO2/m2.year



Energy systems


Heating system: Electric towel heater, wood boiler

Hot water system: Solar thermal (4m2)

Cooling system: No cooling system

Ventilation system: Humidity sensitive Air Handling Unit (VMC Hygro B simple flux)


Renewable systems: Solar thermal and photovoltaic (integrated on the roof) and wood boiler



Awards and recognitions


One of the candidates of Green Building Solutions Awards 2015


Highest score for certification in Bepos Effinergie 2013 and Effinergie +




Additional Information


Project website in French:


Video interviews in French:



Façade construction:

Façade insulation:

Solar systems installation:

Indoor wall construction:

Outdoor finishings:

Blower door test:



Construction21 website:  Positive Social Housing - 3-room house

Construction21 website:  Positive Social Housing - 4-room house

Lessons learnt

The goal was to learn and understand how to make a positive energy house with controlled costs and involving everyone from start to finish as well as using locally sourced materials. It is also important to understand how it is occupied by the inhabitants to subsequently propose technical solutions that will adapt to occupiers and not the reverse. Really making positive energy houses!

Award labels

Additional documents

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