Eco-responsible construction: how much does it cost?
The general public is now much more aware of the respect of the environment in all the gestures of everyday life. These good practices are also entering into construction and renovation. Indeed, the building accounts for 24% of France's ecological footprint, ahead of transport and food. It is estimated that 44% of French energy consumption comes from real estate (dwellings and business premises). So there is still a lot of progress to be made.
The public authorities are striving to put in place increasingly restrictive standards and to offer financing assistance in the event of construction or ecological renovation. Yet, in the general public green building remains associated with the idea of a significant cost or even unaffordable. What are the price differences between traditional construction and ecological construction?
Define the ecological house
Before determining the price of a green home, it is important to give a definition.
It is believed that a home is environmentally friendly when:
• His materials are the most natural possible.
• Gray energy of its materials is low.
• Its manufacturers are familiar with green techniques.
• Its energy consumption is reduced, null or even "positive".
Thanks to these 4 criteria you will be able to define your needs with your craftsman and then make sure that he respects this line of conduct. Through a site such as Prix-pose.com You will be able to get up to 5 free quotes from recognized Craftsmen or Builders of the Environment near you who will help you make the right choices.
What are the possibilities for respecting the environment?
The realization of a green building involves more or less significant expenses that involve making choices during the preparation of the construction or renovation project.
Limited budgets will focus on meeting the latest standards and reducing energy consumption. Those with a larger budget will be able to take advantage of natural materials that will enable them to pursue a goal of building or renovation at 100% eco-responsible.
To determine which solutions are right for your project, it is ideal to obtain several estimates from different professionals.
Passive or bioclimatic houses
To reduce the energy impact of a building, it is best to ensure that the housing requires a small amount of energy, if any at all. This goal can be achieved by respecting very restrictive principles involving the building's exposure, its use of natural and free energies, but above all by avoiding heat losses.
Constructions of this type are named passive houses or bioclimatic houses, they consume 50% less energy than a house at standard RT2012 and 90% less than an old house.
For these dwellings, the supply of energy (electricity, fuel, etc.) is very small and is ultimately an occasional aid. The exposure of the building and its preservation of natural heat allow it to be energy efficient. For a house to be passive, its energy needs must not exceed 30kWh / m² per year while the national average is around 250KWh / m² per year (the equivalent of an energy class E).
Depending on the finish and quality level of the whole, it is estimated that bioclimatic or passive house is about "only" 5% at 10% more expensive than a house RT2012.
Build with biobased materials
Reinforce the insulation and using high-performance materials is not necessarily a guarantee of respect for the environment. For example, one of the most powerful insulators currently is polyurethane. While it reduces heat loss and therefore energy consumption, it is not an environmentally friendly material. Because it is a material of oil origin and its gray energy is very important!
To stay in touch with an ecological approach, you can orient yourself towards natural materials, which exist for almost all posts of a construction.
These materials are generally classified as bio-based and come under the official label "Biobased building" issued by CERQUAL or CEQUAMI.
There are 3 levels for a biobased building:
• 1 level: 42kg / m² of bio-based materials.
• 2 level: 63kg / m² of bio-based materials.
• 3 level: 84kg / m² of bio-based materials.
For example, you can use cellulose wadding instead of rockwool, wood instead of concrete, or linseed oil instead of acrylic paints. Biobased materials are generally 10% to 35% more expensive than traditional materials. It may be necessary to add to this budget specific know-how and therefore higher labor prices.
Positive energy buildings: The norm of the future?
Positive energy buildings or BEPOS are buildings that produce more energy than they consume. The idea may seem counter-intuitive, but using high-performance materials and using solar energy can be achieved.
These houses are generally based on the passive principle or BBC, but go a step further thanks to modern equipment. They can thus produce electricity or reuse rainwater.
The 2020 Environmental Regulation, which will very soon replace the 2012 Thermal Regulation, will mark the advent of the BEPOS houses. It is estimated that the buildings that will be built on this model will display an energy label A, guaranteeing a reduced impact on the environment. The energy expenditure of the BEPOS is lower than that of the passive houses: 0kWh / m² per year.
Although the RE2020 standard has not yet come into force, the LCA-FFB (Manufacturers and Developers of the French Building Federation) estimates that the cost of a BEPOS house requires a higher budget of 15% than 20% to that of a house RT2012.
What is the evolution for eco-construction?
A report from CEREMA (Center of Studies and Expertise on Risks, Environment, Mobility and Development) allows to identify some future trends for green building. For this research organization, the ecological element is becoming more and more present in the building sector, both for construction and for consumption. Green building needs will increase gradually in the coming years.
This institute estimates that the subsidies and subsidies that the public authorities are putting in place will significantly reduce the costs of green buildings.
According to CEREMA, however, there is a significant need for transformation of the entire building sector to lower the dry costs of green buildings. The institute notes, however, a significant decrease in the price of some bio-based materials (cellulose wadding) but not yet that of the whole sector of the ecological house.
When is respect for nature profitable?
To have a realistic view of this type of house, you have to take into account the savings in money made over the long term. These biosourced technologies and materials significantly reduce energy costs. The duration of profitability is estimated between 10 years and 30 years for the moment because the ecological house is not a standard. The democratization of green buildings and new standards will largely lower prices and improve profitability.