Technical aspects of the project


Construction

The key to achieving high-performance buildings is to use prefabricated construction systems. Careful handling of the joins between each element is crucial, especially for ensuring that the buildings are properly sealed.

Every stage of the work was rigorously planned by the developer Les Provinciales, and interaction between the different trades and firms on site was closely coordinated.

Weekly site meetings were held at which the partners in the project received updates on progress and took joint decisions. Videos of the work were taken at each key milestone, as well as during the airtightness tests.

[Translate to Anglais:] Le label BEPOS Effinergie 2013 délivré par CEQUAMI

Summer comfort

 

Comfort in summer weather is primarily assured in both houses by following the principles of bioclimatic architecture and taking account of the available site. Pergolas with terracotta sunscreens and overhanging roofs protect the south-facing walls from the sun, while also ensuring that the buildings still receive plenty of sun in the winter.

The three-bedroom house is built entirely from 30-cm BMI panels. BMIs are insulated terracotta monolith bricks, 30 cm thick. These asymmetric panels have the bulk of their weight on the inner side of the house, which gives them good thermal mass and thus increases summer comfort.

Mudbrick partition walls between the living and sleeping areas regulate humidity within the rooms and increase the feeling of comfort, especially in the summer. In winter, the mudbrick gently diffuses the heat from the wood pellet stove.

Performance monitoring

 

Thermal mass and moisture regulation cannot currently be modelled using the software specified by TH-BCE insulation regulations. The buildings have therefore been fitted with temperature and humidity sensors to provide evidence of their effectiveness.

Respecting the environment


Thanks to their bioclimatic architecture, their design and the choice of prefabrication systems, the T3 and T4 houses are sparing consumers of energy – in fact, they use less energy than they produce. Solar panels built into the roof generate enough power to offset not only the energy used for heat, light and ventilation but also the power used by the tenants for other purposes, such as domestic appliances and media equipment.

The two-bedroom house generates domestic hot water from a heat pump water heater linked to an innovative TERREAL system for recovering the energy that circulates naturally under the roof tiles, significantly increasing the heater's performance scores.

In the three-bedroom house, domestic hot water is generated by 4m² of thermal solar panels connected to a storage tank.

The houses are designed to collect rainwater, supplying enough to ensure that the plants are kept watered.

The HSP homes are located in Castelnaudary in the "eco-district" of the Vallons du Griffoul development zone.

Les Vallons du Griffoul

 

The "eco-district" in the Vallons du Griffoul development zone complements the existing urban fabric of Castelnaudary and complies fully with the municipality's sustainable development objectives, namely:

  • Urban form and integration: limited building height, reduced car use, provision of cycleways and pedestrian routes and easy access to public transport.
  •  

  • Mixed housing: housing will be a mixture of individual houses, small developments and apartment blocks; one quarter will be social housing.
  •  

  • Water: rainwater collection, low-consumption equipment, welcome leaflets for occupants.
  • Biodiversity: conservation of wooded areas
  •  

  • Bioclimatic orientation: south-facing living areas
  •  

  • Energy: low-energy buildings with solar hot water.
  •  

  • Waste: waste-sorting areas and composters.
  •  

  • Materials: local, natural, certified.
  •  

  • No excessive costs.
  •  

  • Collective action.

Terracotta materials

 

The materials used in the construction of these houses are locally produced from clay and sand. Their life cycle has been analysed. FDES sheets (environmental and health declaration sheet) are available for several of them free of charge on the database at www.inies.fr, or alternatively on request from TERREAL.

Keeping costs down


Rent-controlled homes at a reasonable cost

Ensuring that Project HSP can be replicated elsewhere means keeping the costs of a positive energy building to a level that remains viable for the construction and maintenance of social housing.


Important features of Project HSP therefore include:

- a detailed cost-effectiveness study, shared from day one
- keeping site costs and lead times under control throughout the construction phase
- overall costs close to the construction costs of homes complying with the 2012 Heat Regulations (excluding solar heating)
- a simple, robust and durable building envelope which minimises the use of complex or expensive-to-maintain equipment that would drive up the overall cost.


Total cost: €300,000
€1,170 per m² for the two-bedroom house
€1,330 per m² for the three-bedroom house

Fuel poverty:

It is now widely assumed that gas and electricity prices will carry on rising, which is a source of concern to households and social landlords.

Keeping energy bills down in a high-performance home is a way to give back purchasing power to poorer households.

To ensure that poorer households do not fall back into fuel poverty (where fuel bills amount to 10% of household income), the HSP house of 2020 will need to:

  • keep energy use down throughout its lifetime, so as to stay within the means of its residents
  • be simple and robust, with low capital investment and maintenance costs, in order to be viable for social landlords.

Access for the disabled

Under current regulations, any house built for rental must be capable of being made accessible for disabled persons, regardless of their disability.

In line with the wishes of Habitat Audois, the two HSP houses were designed from the outset to meet all the requirements of disabled people.

They are built as bungalows, with wide doorways and sufficient space to manoeuvre a wheelchair in every room.

A strong local partnership

While it was the technical skills and the institutional environment provided by Ademe and the Languedoc-Roussillon region that made Project HSP possible, it is the quality of the relationship at a human level that made the project a success.

Shared values, physical proximity and the determination to ensure every key factor was provided made HSP an exemplary project that bonded us together.

Project HSP – Human values


Human values were central to the Habitat Social Positif project

As with Habitat Audois's previous signature projects, people were central to Project HSP.

A new approach was followed which goes beyond the issues of home quality, energy use and year-round comfort per se. The majority of the energy consumption in a high-performance building is energy use directly linked to the occupants themselves, for domestic appliances, media devices and so on. Steps are therefore being taken to provide tenants with information about their energy consumption, so that they can understand it and control it more effectively.

These steps were designed in conjunction with the tenants and are being provided for an expected period of three years.

The experience gained will be used as a basis for tailoring similar measures for other properties in the Municipality of Castelnaudary and in Habitat Audois's portfolio.

The devices installed as part of Project HSP will make it possible to see how the homes perform in real, tenanted conditions. This will serve as a base for TERREAL to develop new construction systems, as well as being providing useful information to the Languedoc-Roussillon region and Ademe for future ideas and programmes.

Access for the disabled

Under current regulations, any house built for rental must be capable of being made accessible for disabled persons, regardless of their disability.

In line with the wishes of Habitat Audois, the two HSP houses were designed from the outset to meet all the requirements of disabled people.

They are built as bungalows, with wide doorways and sufficient space to manoeuvre a wheelchair in every room.

A strong local partnership

While it was the technical skills and the institutional environment provided by Ademe and the Languedoc-Roussillon region that made Project HSP possible, it is the quality of the relationship at a human level that made the project a success.

Shared values, physical proximity and the determination to ensure every key factor was provided made HSP an exemplary project that bonded us together.