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RT 2012: What implications for the construction of my house in the South West?

Building greener homes

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Divide by three the energy consumption of maisons built today, in the South West in particular, such was the tremendous leap forward of the thermal regulations 2012, said RT 2012. Besides small monthly bills, houses built under this scheme are more Comfortable but also more healthy. Explanations.


RT 2012: build your house to consume less energy

Since the 1er January 2013, a new house, respects the thermic regulation, said RT 2012. As a result, the inhabitants consume a lot less energy to chauffer ou refresh home and prepare thehot water. also called low energy houses, houses RT 2012 assume that a well-designed and well-equipped building consumes much less energy than a conventional building.

RT 2012 has developed indicators to analyze the performances du building in three main areas: bioclimatic needs of the building (Bbiomax), The primary energy consumption (Cepmax) and summer comfort (Ticref).

Official presentation of the RT 2012 here

– Good to know a new RE 2020 regulation for 2021

In 2021, new, more demanding regulations should come into force, previously called RE 2020. But any building permit filing before this date will allow you to remain under the RT 2012 regime.

RT 2012 houses: a bioclimatic house (Bbiomax) adapted to the South-West region

La bioclimatic design advocated by RT 2012 obliges builders to take into account the environment of the house. Finally, the builders are rediscovering the knowledge of our ancestors. Full of common sense, our old homes were designed to take advantage of the warmth and sunlight while protecting yourself during the summer season.

The different points to be treated in a bioclimatic house.
©: Ministry of Sustainable Development

– Take advantage of solar gain in the South-West

The low energy houses will therefore be oriented so that the sunshine enter the house in winter. THE South West being a sunny region for a good part of the year, it would be a shame not to take advantage of these free calories ! Some big Windows full performance South are a real asset in winter.

– High performance insulation

Insulation will maintain a more stable temperature in the House. There is no minimum insulation thickness. It's here overall performance for the maison which is taken into account.

Floor, walls, roof, all walls exterior must be isolated. Treatment of thermal bridges is an obligation. The insulation must therefore be continuous in order to avoid cold areas on which mold can develop.

– An airtight house

RT 2012 houses are airtight, i.e. they limit the flow of air p. In fact, the airtightness of buildings depends in particular on the effectiveness of insulation systems. This requirement of RT 2012 is checked at the end of the work.

More information on the website of the Ministries of Ecological Transition and Territorial Cohesion.

However, the air must be renewed regularly. There indoor air quality will thus be guaranteed by a system of efficient mechanical ventilation.

– RT 2012 imposes a minimum glazed surface

With RT 2012, priority to large windows. 1/6 of the living area must consist of Windows. Goal, let enter the sun and calories in winter, but also promote thenatural lighting and save electricity.

– RT 2012 imposes a minimum glazed surface

With RT 2012, priority to large windows. 1/6 of the living area must consist of Windows. Goal, let enter the sun and calories in winter, but also promote thenatural lighting and save electricity.


Limit energy consumption (Cepmax)

Here are taken into account the energy consumption related to heating, To thelighting, domestic hot water preparation, or at the ventilation housing. THE amenities chosen in the houses RT 2012 are efficient and consume little energy.

Install high-performance equipment for a “Cmax meeting RT 2012
©: Ministry of Sustainable Development

– Use renewable energies

RT 2012 requires the use of renewable energies to heat, produce theHot water ou make electricity.

Heat pumps, photovoltaic panels, thermodynamic water heater, solar water heater, wood heating, this economical equipment to use has now largely proven itself in the home. The value of the coefficient Cepmax rises in the South West à 50 kWhEP/m²/year but is modulated according to geographical location, altitude, etc.


Maisons RT 2012: summer comfort, even without air conditioning!


According to RT 2012, summer comfort is reached when the indoor temperature, even after 5 hot days, must remain below a reference temperature without having to resort to a cooling system. In fact, airtight and well-insulated buildings tend to trap heat. To avoid overheating, it is therefore necessary to use tricks to prevent the sun's rays from entering. In the South West, toward Toulouse, Bordeaux , Agen or in Landes, we will place roof overhangs, pergolas to sun breezes in front of the South windows which protects from these too hot rays in summer. In the same way it will be necessary to use materials with strong inertia, like the tiling and to bet on a nocturnal overventilation.

In some cases, the air conditioning is even possible.

In the southwest, it is possible to have a cool house in summer without air conditioning


La RT 2012 does not impose a way of building on individual home builders. Depending on your requirements, you can favor one or the other of these performances. At the house of Sic houses, you may prefer an ultra-insulated house, very efficient from a bioclimatic point of view for example, with efficient but classic equipment. On the contrary, you can have a envelope less isolated but make electricity from the energy solar thanks to the installation of photovoltaic panels for example.


Learn more about individual house construction stages


Today, Sic houses, builders of individual houses are already anticipating the next thermal regulation which should be called RE 2020 and is expected in summer 2021. Explanation in this article.


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