Times are changing, and with them real estate and the construction sector: ecological houses, tiny houses, autonomous houses, bioclimatic houses and ecological houses are revolutionizing the approach to housing. What are their advantages and their impact on ecology? Some tips to help you find your way.
Housing, a sector to be reinvented
The building and construction sector is one of the main emitters of greenhouse gases and thus contributes significantly to global warming . The carbon footprint of construction activities is poor. They emit CO2 but also methane and hydrofluorocarbons which produce GHGs (greenhouse gases) throughout their life cycle. From the extraction of raw materials, their transformation, the production of construction materials such as cement or concrete, through the construction of buildings (transport, machinery on construction sites, etc.) to their end of life and their often poor quality recycling. We call all this "gray energy", that is to say that which is consumed indirectly and invisibly, especially upstream of what is visible to the end consumer.
Finally, excessive urbanization is obviously very harmful to the environment: agricultural and natural areas are sacrificed for the benefit of constructions that destroy local ecosystems . Industrial or commercial zones also transform the soils which are covered with tar to make roads or giant parking lots.
The principle of ecological houses
Eco-construction is now appealing to both individuals and building professionals. The objective is twofold: to save energy and build with the least impact on the environment. An ecological house requires attention at all stages of the life cycle: from the design, which must consider the building in harmony with the natural environment that surrounds it and the construction site, which must reduce waste, to the choice of natural, recyclable and ecological materials (non-toxic), to the developments, which must all go in the direction of energy savings, whether in the choice of equipment or alternative installations such as solar panels, etc. Local suppliers and materials are preferred. The project must be designed to be in synergy with the external elements: creation of shade in relation to the sun, reinforcement and plantations facing the wind, adapted windows, etc.
Heating, energy, lighting, water: ecology at all levels
The first thing that comes to mind is of course the choice of natural materials such as wood, clay bricks or even straw, particularly for thermal insulation with numerous natural insulation solutions such as linen or hemp wool, wood fibres, etc.
The architect and the builder will also think about ventilation to regulate the temperature using as little energy as possible in summer to keep the house cool and in winter to avoid losing heat. Heating systems must be carefully chosen: autonomous heat pumps that operate using air and water, wood stoves especially if they use wood pellets or waste such as sawdust, solar panels to reduce energy consumption by carefully studying the orientation and inclination, to partially heat the home. Indeed, all these solutions are not sufficient given intermittent sunshine. Similarly, an individual wind turbine is unlikely to meet an energy demand, because it is very expensive to purchase and is not very profitable. Low-energy light bulbs are also preferred, the price of which is quickly paid for by an unbeatable lifespan, with a special mention for LEDs, which have very low energy consumption. Finally, a house cannot be ecological without systems to save water, nor without a rainwater collector for watering, cleaning or to provide flushing, which can also be completely done without with dry toilets.
Different types of eco-friendly houses
As the sector is developing rapidly, there are many variations of ecological houses.
- “Bioclimatic houses” must have the High Environmental Quality (HQE) label. In addition to the principles of eco-construction, they are focused on strategies for optimizing the orientation and exposure of the house to reduce lighting and heating needs.
- Low-energy buildings target the reduction of energy consumption and must not exceed 50 kWh per square meter/year to have the BBC label.
- To have the Passivhaus or Passive Energy Building (BEPAS) label, “passive houses” must produce their own energy and be able to do without heating. They require a feasibility study because the specifications are very demanding, particularly in terms of insulation and waterproofing, which explains the high price.
- Finally, positive houses are the most advanced ecological houses because they combine all the characteristics of Passivhaus houses, in addition to installations to produce enough energy to be totally autonomous... or even more than necessary!
Nomadic wooden houses and tiny houses
Be careful, most eco-friendly houses use a lot of wood, but a wooden house is not necessarily eco-friendly! On the other hand, new generations of eco-friendly wooden houses are appearing. They use bio-sourced materials and wood of local or even hyper-local origin. Some are even built with trees from their own land using mobile sawmills. This sustainable approach continues with the choice of untreated wood. A bias that aims to give life to a habitat that is as healthy as possible, free of toxic volatile molecules. These principles are particularly suited to new nomadic habitats such as tiny houses, mobile, scalable, and ecological mini houses. These autonomous nomadic houses go hand in hand with an alternative lifestyle choice guided by the principle of sobriety which implies a certain minimalism. Tiny houses, inexpensive and energy-efficient, perfectly meet this concept.
Be careful, most eco-friendly houses use a lot of wood, but a wooden house is not necessarily eco-friendly! On the other hand, new generations of eco-friendly wooden houses are appearing. They use bio-sourced materials and wood of local or even hyper-local origin. Some are even built with trees from their own land using mobile sawmills. This sustainable approach continues with the choice of untreated wood. A bias that aims to give life to a habitat that is as healthy as possible, free of toxic volatile molecules. These principles are particularly suited to new nomadic habitats such as tiny houses, mobile, scalable, and ecological mini houses. These autonomous nomadic houses go hand in hand with an alternative lifestyle choice guided by the principle of sobriety which implies a certain minimalism. Tiny houses, inexpensive and energy-efficient, perfectly meet this concept.
Faced with the climate emergency, the construction sector must absolutely transform itself, and quickly. Ecological houses, which are still not very widespread, are on the way to becoming the new norm. These houses are constantly developing in order to be able to combine energy savings and comfort in synergy with nature and not by damaging it. It remains to extend these performances to old houses. On this subject, the law requires that owners whose energy consumption exceeds 330 kWh/m²/year must carry out an energy renovation before 2025. In addition, the owner must carry out an energy performance diagnosis when selling his house in order to reduce the number of "thermal sieves".
