It is now a fact: the fragile balance that sustains our planet is increasingly compromised by the massive and indiscriminate exploitation of natural resources by humanity. A large part of the current residential buildings, in fact, consume large amounts of energy and are built with polluting materials, which inevitably degrade both the external and internal environment with significant repercussions on human health. The combination of these negative factors has led to the emergence of a new awareness in terms of social responsibility and sustainability.
Not even the building sector is immune to the ecological transition underway and all operators have been called to face the new challenges of a constantly changing and evolving market. How then to respond to these changes?
To create buildings that have the least impact on the psycho-physical well-being of man and the environment. This is the primary objective of green building, a green alternative to traditional architecture, which promotes the use of natural building materials, technologies and design methods with low environmental impact in full respect of sustainable development and the landscape context.
Building in green building therefore means respecting the close relationship between environment, building and man, limiting the use of non-renewable resources and the use of materials that are harmful to the ecosystem and our health as much as possible.
Let’s see together in more detail what green building consists of, the building materials used and the main advantages in terms of energy efficiency.
How green buildings are made
A truly green building begins to take shape starting from paper. A project studied with extreme functional care and technical precision, in fact, foresees to place the most frequented rooms towards the south: in this way the heat of the sun will be exploited to its maximum during the winter season.
At the same time, the windows and their dimensions will be designed to ensure maximum efficiency and the best possible exposure to sunlight.
Another essential factor of a green home is thermal insulation: the walls, made of natural materials, allow you to preserve the warmth of domestic spaces in winter and keep them cool in summer. In addition, the absence of thermal bridges and heat loss to the outside almost completely avoids the risk of mold, condensation and stagnation of humidity.
Therefore, it is clear that a green building, to be defined as such, must have an entirely zero impact life cycle: from its construction to its demolition. A building that can be recycled in all its parts, without any release of toxic or harmful residual substances for the environment.
To summarize what has been said so far, the philosophy behind green buildings provides a design approach based on four essential principles, such as:
- Reduction of energy costs
Energy saving represents the deepest essence of the concept of green building. For this, it is necessary to design low-consumption domestic systems with bioclimatic criteria: photovoltaic solar panels, thermal insulation techniques, natural ventilation, geothermal technology and correct orientation of the environments with respect to solar exposure.
- Respect for the environment
At the time of construction, green buildings must take into account all the variables of the territory in which they are inserted: temperature, lighting, slopes, humidity, presence of vegetation and altitude. The ultimate goal is to minimize water waste and CO2 emissions.
- Living well-being
For those who live in a green building, maximum comfort is given by a safe, healthy and pleasant environment to live in. Eliminating or minimizing risk factors is essential to guarantee all kinds of comfort: thermal, hygrometric, light and acoustic.
- Use of bio-ecological materials
The construction of a house in green building involves the use of natural materials, easily disposable and, above all, with a low environmental impact: from wood to stone, from straw to cellulose fiber.
Green building materials: not only wood, but also steel and aluminum
As just mentioned, green building materials play a key role in the construction of an eco-sustainable building. However, in order to speak of a real organic home, their use alone is not entirely sufficient: raw materials must come from certified productions, while the entire production process always takes place according to principles of sustainability and respect for the environment.
So what are the most used materials in the green building sector?
Stone, cork, raw earth, straw, bamboo, linen, coconut fiber and cellulose wool are just some of a long list, which sees wood, steel and aluminum at the top.
Considered the symbol of green buildings, wood is the perfect natural building material. Thanks to its extraordinary static resistance, biodegradability and low energy expenditure in processing, this raw material does not release pollutants and is also a perfect insulator that allows considerable energy savings.
The second material that today lends itself optimally to the construction of green buildings is steel: a 100% recyclable metal, for an unlimited number of times. This feature, in addition to enhancing the concept of circular economy, allows you to reduce the environmental impact and lower the times and costs of implementation.
The third material, mostly used in green building for windows, doors and roofs, can be 100% recycled and reused indefinitely, to give life to new products every time. In fact, it is estimated that 70% of the aluminum produced all over the world is still in circulation. Specifically, about 50% of all raw aluminum produced in Western Europe comes from recovered and recycled material, while in Italy the percentage reaches 90%.
Unlike wood, steel and aluminum are not conductors of moisture and this helps to keep the home environment healthier and away from the onset of bacteria and mold. In addition, their excellent thermal-acoustic insulation capacity, lightness and extreme ductility make it possible to ensure a higher level of home comfort without neglecting seismic safety and the structural component of the building.
In particular, steel and aluminum expanded metal is one of the most environmentally friendly metal products on the market today: the production process does not generate waste, the material savings are considerable and the impact of emissions is zero.
In fact, choosing to make facades or sunscreen panels in expanded metal or stainless steel wire mesh means using a material that will help keep interiors fresher and brighter thus helping to reduce the impact of air conditioning systems.
Green building materials: energy saving
If you are wondering how to save on bills, energy self-sufficiency is the first essential condition to have a house with almost zero environmental impact and, consequently, reduce costs for domestic users.
In recent years, in fact, the trend of designing according to the standards of eco-sustainability and creating buildings with zero energy balance, that is designed to achieve complete autonomy from an energy point of view, is increasingly consolidating.
It is clear that this involves significant savings both in the water, electricity and gas bills and in the overall management of the entire home.
For example, in the presence of proper management of household appliances, a system of photovoltaic panels allows to obtain self-consumption levels equal to 30%. If the heat pump for domestic hot water is also connected to this, 60% is reached, while, if you decide to also install energy storage devices, you can reach 80% independence from the network.
Therefore, the combination of these systems with natural insulating materials for green building will allow you to have a real home with zero consumption and emissions: an eco-green building capable of balancing the energy consumed with the self-produced one, exploiting renewable sources (wind energy, solar or geothermal).
In summary, therefore, energy saving in green building can take place in two ways:
- on-site production of electricity and heat through the installation of solar panels or geothermal coils
- passive exploitation of the house itself through the use of natural insulating materials during construction
According to the Global Alliance for Buildings and Construction report presented at COP25 in Madrid in 2019, the construction sector is responsible for 39% of global CO2 emissions and has an energy weight in terms of consumption of 36%.
How to cope with this problem? Accelerating the decarbonisation process is only the first step towards the ecological transition. In order to run for cover, it is necessary to respond to the current bioclimatic and sustainable design criteria, adopting a new green model to be applied to the entire life cycle of buildings.
In light of this, the future of green building now seems to have been traced: from a simple eco-friendly alternative to a real need to save the planet.