ecological houses

Which ecological or low-consumption house to build or buy in 2021?

Since January 1, 2021, you must ensure that you comply with the new construction standards of the 2020 thermal regulations (RT2020). The objective of this approach is to make your building more environmentally friendly and more energy efficient. Here are some examples of ecological houses that existed long before the RT2020 and to be considered in order to achieve the objectives of RT2020 in 2021 ...

These different types of ecological houses are unfortunately still too rare and too little known in France. The promoters rarely take technological risks therefore on the investment. They simply apply the standards of the thermal regulations in force. And these standards are unfortunately not always well applied for reasons of additional costs or delays.

Do not forget also that an old accommodation, smart and efficient refurbishment, will often be greener overall than any new construction because the energy and CO2 associated with its construction have already been amortized. It may thus be interesting to makeeco renovation rather than considering a new construction…. Provided that the potential for renovation is there. Get professional advice and never stay on the first advice you received. In other words, seek as much professional advice as possible.

We believe that it is very important to know (and make known) these different types of ecological houses and the techniques for any good professional of the real estate, in particular if you want become a real estate negotiator

Overview of homes or ecological houses that exist in 2021 ... We are talking here about truly ecological houses, no pseudo ecological or real estate greenwashing!

La passive house

It is the top of the ecological house from an energy bill point of view. A house is said to be passive if it consumes less than 15 kWh per year and per m² of primary energy! Which is very little!

For example, a passive house without any other source of energy (no wood, no gas, no fuel oil, etc.) of 150 m² in France should not consume more than 15 * 150 / 2,58 = 872 kWh of electricity per year (2,58 is the coefficient for France for converting EdF kWh into primary kWh). And this regardless of the number of people who live there.

Indeed, thanks to its structure, orientation, tightness and thermal insulation, the passive house makes it possible to make the most of the free contributions of solar radiation in a house throughout the year. Its thermal insulation and its overall design are such that the energy input of the occupants is sufficient to do without central heating. And this even in the North of France! By building a passive house, you allow the Sun to heat various parts of your house such as walls, floors and certain objects, reducing your heating needs at the same time. The passivity of a house also concerns its air conditioning system and this may cause problems with repeated heat waves.

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The passive house was therefore designed to have very low consumption and generates little greenhouse gas, thanks to its reduced energy consumption. But it often generated more greenhouse gases during its construction, which is more complex and more expensive than the others.

La solar house

The solar house is a somewhat exaggerated name for a house equipped with at least two solar panels. In fact, housing that has of photovoltaic or thermal panels can also get this name.

Here is a real solar house whose south roof is entirely covered with solar panels: 70 m² of thermal solar panels with inter-seasonal energy storage in a solar buffer of several tens of thousands of liters of water and 16 m² of solar panels photovoltaic.

solar house

This solar house is 80% energy self-sufficient: that is, it actually consumes 1/5 of what a traditional equivalent house would consume in the same region. This house also has a thermal energy storage buffer see explanations below in this article.

You can chat with its owner here: large-capacity solar house

There are also hybrid solar panels or PVT (Thermal Photovoltaic) which combine Photovoltaic and Solar Thermal (air or water), this allows the overall use of a smaller surface and optimizes, a little, the production of solar electricity.

THEHQE housing

The concept brought by the High Environmental Quality label aims to reduce energy consumption in new buildings while improving the comfort of residents. To do this, it relies on the 3 pillars of sustainable development:

  • Ecological contribution
  • Life quality
  • Economic performance

Although the price of HQE housing is generally between 10 and 25% higher than that of a classic house, if you decide to embark on this project, you will be able to make it profitable in the long term. In addition, there are many programs that allow you to benefit from construction aid.

La BBC house in wood

The low-consumption building or BBC in wood is a habitat that fits into the challenges of energy performance and sustainable development. Thanks to the choice of wood, this type of housing allows you to benefit from reduced energy consumption throughout the year.

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To respect the RT 2020, you can make this choice which was already in accordance with the standards of the RT 2012. To label your house, it will suffice to have a inspection of building materials, file a thermal report and perform an air permeability test.

La straw house

Among the most ecological materials that can be used to build a house, there is straw. It is finally a partial return to the mud houses of the Middle Ages, some of which are still standing… unlike the fortified castles of the same period!

Completely renewable and offering very interesting insulation capacities, this material also allows you to reduce your bill during construction and housing. Straw costs less than conventional building materials. But the technique requires good knowledge and is offered very little by real estate developers.

In a classic style, we generally find in these houses exterior walls made of grain straw bales (rye, wheat or barley). Inside, straw is also used to make partitions and serves as insulation for attics and roofs. To improve thermal and sound insulation and for naturally regulate heat and humidity of your home, this choice of construction is ideal.

Unfortunately, straw houses are not widely used, no doubt for psychological fears ...

Home to energy storage

Choosing natural materials helps lower the carbon footprint of your construction.

Applying insulation respecting RT2020 will greatly reduce your heating bills and provide you with interesting thermal comfort.

Using bio-climatism will give you free energy throughout the life of the home.

But all these techniques will probably not be enough to make you truly autonomous in energy, at least in the northern part of France or Europe ...

Some have imagined  energy storage techniques, electric of course, via batteries ... but also from inter-seasonal solar thermal energy storage, that is to say over several weeks or months. Medium-term energy storage. This can be achieved through different technological solutions for thermal energy storage.

So we can storing heat in phase change materials, such as palm oil, or in the ground as is the case for an entire neighborhood in Canada with the summer for winter heat storage project at Drake Landing Solar Community

It is a pilot project and unique in the world that stores energy from summer to winter for more than 40 homes

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These energy storage techniques, heat or electricity, significantly reduce energy consumption. annual housing. Be careful, the initial investment in energy storage is often quite substantial but, if it is reliable, it pays for itself over the years! This is the price to pay towards real energy autonomy.

Video of a solar energy storage house in Friborg:

The Earthship, the recycled autonomous house

Advocating a construction based on recycled materials and fully autonomous in energy and water, the concept of earthship house was invented in the USA by Mickael Reynolds in the 70s. It is gaining more and more followers in France and elsewhere in the world but often comes up against the legislation in force for its particular architectural forms and the construction materials that She uses !

earthship concept

Apart from the generally unusual architecture of these homes, you can find used tires, glass bottles and cans. However, it is not uncommon to find very beautiful homes made with wood, straw or even lime, materials that are better suited to rural dwellings than to houses in town.

You can download a guide to EarthShip houses and watch 3 Earthship presentation videos

3D printed houses

To end this comparison, it is advisable to talk about all new construction techniques, that is to say 3D printed houses which can be quite ecological in certain aspects!

The arrival of 3D printers and their ability to design ever larger structures have also affected the construction sector. Thanks to innovative techniques, these machines are now able to make houses from mixtures of cement, concrete, earth and clay or other natural malleable material. This in a minimum of time and with a minimum of human effort. It is a particularly fast and ecological construction technique if it uses the right materials. Without counting the foundations or the finishes, a house can be printed in less than 48 hours.

3D printing in construction also makes it possible to obtain original shapes allowing certain thermal and ecological advantages, such as hobbit houses, a modern and more natural variation of earthlink houses.

You can see here the 3D printed house video

In the long term, 3D manufacturing could replace traditional methods that are more expensive in terms of material and energy and could even be used to erect the first foundations of the lunar conquest and the planet Mars according to engineers from the European Space Agency and the NASA.

Do you have a question about one of these techniques? Use the forum sustainable development or search

1 comment on “Which ecological or low-energy house to build or buy in 2021?”

  1. All the points you raise are correct, but I will add two crucial points for the proper functioning of a so-called passive house: the quality of the airtightness of the envelope and the efficiency of the double flow ventilation. These two points are essential for: validating the energy quality of the building, thermal comfort, acoustic comfort, indoor air quality, a durable envelope over time.

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