The environmental sustainability of a building is conditioned by the materials with which it is built. The concept might seem simple but, in architecture, the materials used for building involve the building. Reflecting on this, which seems trivial, is instead the key to solving many problems of environmental sustainability of buildings.
The overview of materials used in architecture is useful for future designers, to understand how the choice of the most suitable building material with respect to the needs of the project is the first fundamental and decisive operation to be carried out for a correct architectural design of buildings.
The environmental sustainability of buildings is of fundamental importance for human beings.
Humans use buildings and therefore the materiality of a building is what our bodies come into direct contact with.
A cold metal handle, the warm wooden wall and the rigid glass window would create a completely different atmosphere if they were, for example, a hard glass handle, a cold metal wall or a warm wooden window, perfectly feasible with the new translucent wood of KTH. Materiality is as important as the shape, function and position of a building, or rather, is closely connected to all three things.
There are materials used in architecture not only known to architects, but there are many others that are fundamental for contemporary architecture, for resilient architecture, which are not known at all. The following list is a selection of the 16 design materials of all the architects but also of those who care about the problems related to environmental sustainability and energy saving, in which the building and the recent development of the concept of green building play a role of primary importance.
Concrete is the most widely used building material in the world, and represented the starting point for a new way of building, able to overcome the construction limits imposed by traditional construction technologies. It is composed of a binder (eg cement) plus aggregates and water. Different additives, used only since the last decades following the technological development of the buildings, serve to improve some characteristics and quality of the concrete. The placement of steel bars, which give rise to reinforced concrete, properly shaped, allows the concrete to withstand the tensile stresses. If it is difficult, at least for now, to think of being able to do without concrete, it is also true that this material has significant environmental impacts. The research goes on to try to reduce the carbon footprint which, according to estimates, is equal to 3-7% of total emissions worldwide. Since 2013, a Canadian startup has made some changes to the process of obtaining concrete: by adding more CO2 in the initial phase, a more resistant product is obtained which does not release emissions over time. Cement is one of the sectors considered most difficult to de-carbonize: to limit its environmental impact, Carbon Brief ends, it will be necessary to focus also on circular economy methods, which include, for example, the recycling and re-use of materials and the architectural design of lighter, longer-lasting and efficient buildings thanks to bio-construction techniques. The new frontier of the evolution of concrete is connected with the study of its rheological properties, which led to the proposal of the SC.C. (Self Compacting Concrete). This can be considered one of the most important innovations in concrete production technology and its implementation. The new studies and the new technological researches of the modern world have led to the production of concretes with high characteristics of resistance, workability and different properties so as to bring man to works of extreme engineering.
One of the oldest and most traditional and natural building materials used in construction is wood. Wood has been able to renew itself, rediscover high-tech and contemporary architecture, in many cases overcoming preconceptions and prejudices related to its use in housing facilities. Wood is establishing itself as a material of the future, with qualities that allow buildings to reach different heights, one hundred percent recyclability, low thermal dispersion and high anti-seismicity. Wood also plays a fundamental role in the fight against climate change, as forests reduce the amount of carbon dioxide present in the atmosphere and, compared to other building materials, each cubic meter of timber used saves on average emissions per 1, 1 tons of CO2. As an example, the production of a wooden beam requires one-sixth of the energy needed to produce an element of equivalent strength in steel, while the construction of a wooden house takes half the energy necessary for the construction of the same house made in brick or reinforced concrete.
New York City and Chicago have always been the main centers for the construction of skyscrapers, since the end of the nineteenth century, in New York, the first buildings with cast iron armor, the Cast Iron, can still be seen in the SoHo district. While in Chicago, after the fire of 1871 that had completely destroyed the city center, skyscrapers were built with steel framework, more resistant than cast iron. In those years, the possibility of using materials that were considered new at the time, such as cast iron, steel and glass, offered designers unthinkable perspectives. The city skyline, as we know it, has multiplied thanks to the discovery of steel, commonly used as a reinforcement but which can be used as a second skin in many building structures. The large spans are above all the field of use in which materials such as steel, of high resistance, can be exploited optimally, above all through the use of reticular systems. But there are also other features that play a fundamental role in the world of production and exhibition: the speed of execution; modularity; the possibility of expansion; the possibility of relocation. All elements in which the specificities of steel construction can be enhanced.
4. The (bio) plastic
Although plastic may seem like an unsustainable material, you shouldn’t be so quick to judge the possibilities that plastic holds. We produce so much and recently we hear about bioplastics. On the subject of bioplastics, the construction market is booming. The great increase in the use of bio-based PUR also concerns this area of application.
The main use lies in fact in the manufacture of rigid foam for thermal insulation of buildings to replace equivalents derived exclusively from oil.
There are still few examples of the use of bioplastics in building.
The use of bio-based polymers allows an improvement in long-term environmental performance.
The use of stone as a building material dates back to prehistoric times. The name of “megalithic civilization”, with which the first appearances of man’s building activity are designated, derives precisely from the appearance of the leftovers that there have come in the form of constructions made of stones and natural boulders of dimensions huge. Natural stones for use in construction have existed for millions of years and possess extraordinary characteristics of strength, compactness and durability. There are many works that testify to their use and their resistance over time and time: the Egyptian Pyramids, the monolithic structures of Stonehenge, the Colosseum in Rome, the many cathedrals scattered around the planet. Precisely because of these characteristics, stones have taken on magical meanings and unique properties in each of them over time and in society. Natural stones are fireproof, hygienic, non-toxic and have a great variety of textures, colors and strengths.
6. Textile materials
In recent years we have been able to witness the development of mobile façade systems aimed at solar shading, where in any case there are adjustable vertical or horizontal elements, made of textile material (as well as wood, metal or glass).
Some experiments with dynamic and kinetic facades made with the use of textile materials have already been completed and allow for considerable potential. The possibility to use on the facades both closed and open mesh fabrics, with a wide chromatic range, represents another aspect of considerable interest in the application of technical textile in architecture. Some experiments with dynamic and kinetic facades made with the use of textile materials have already been completed and allow for considerable potential. The possibility to use on the facades both closed and open mesh fabrics, with a wide chromatic range, represents another aspect of considerable interest in the application of technical textile in architecture. For each of them the main values and characteristics of the materials have been indicated, such as the average duration, resistance to aging and dirt, translucency, flame resistance, bending resistance, construction costs and applications. Recommended. These interventions take into account the figurative and chromatic value of the surfaces, the texture, the perceptive qualities of the coatings are used, they play with structural lightness and transparency, reflections, that is with those details that contribute to making architecture live in its place. , through materials and technologies that cause relationships, interferences and interactions. Transformability is connected to the concept of sensoriality. The building can thus become the screen that radiates lights, colors, sounds and communicate information.
Our most used material to obtain transparency and light is undoubtedly glass, one of the most used façade elements in contemporary architecture. Much progress has been made, attempting to extend its properties to create an “intelligent” reactive glass. The “smart glasses” are materials capable of responding dynamically to environmental changes, guaranteeing high comfort within the premises. The advantages:
- better control of light inputs;
- better control of energy needs;
- better reduction of energy losses;
- better optimization of energy consumption;
- best design and technical solutions of valuable value.
These windows can be self-regulating or electrically activated according to the user’s wishes. Smart glasses therefore know how to respond to external stimuli by changing the characteristics of transparency, brightness, color and the degree of shielding of solar radiation, while maintaining the structural properties unaltered. Use is particularly indicated in residential and architectural civil buildings, especially for buildings of the future that will be oriented towards the sustainability of the use of natural resources and energy saving.
8. The bricks
Despite its rigid and rectangular shape, the brick architecture has proven to be able to obtain particular and aesthetically beautiful structures. The use of bricks allows to combine the advantages of factory construction – cost-effectiveness, quality, speed – with the most well-known and appreciated building system in Italy. There is a link between brick, design, natural environment and sustainability. “Clay is the earth under our feet”. History teaches us that brick buildings do not only have a long life, but they are also exceptionally durable in terms of efficiency, and this is a comforting thought for those investing in real estate. The brick as an unchanged element, a constant link between history and contemporaneity (another “red thread” in the most recent reflections on its raison d’être), demonstrates its role in the project occasions involving restructuring and restoration, sometimes of buildings with centuries of life. This fact has allowed us to develop the knowledge of the unique qualities of building materials belonging to the family of ceramics, qualities such as, for example, the beautiful patina of aging, ease of cleaning, great flexibility, reuse and inertia.
Kevlar is an aramid synthetic fiber invented in 1965, and therefore recently discovered. A more resistant material than metal reinforcement, with considerable tensile strength, Kevlar is certainly an advantage when it comes to building large structures. Aramid fibers are not suitable for the restoration of reinforced concrete structures where instead the carbon fibers find ample space. Their use is mostly indicated in the reinforcement of masonry structures for which a high elastic modulus is not necessary. An interesting example of the use of aramid fibers in the restoration of masonry structures is that which was carried out in the interventions of securing and restoring the vaults of the Basilica of St. Francesco of Assisi following the known seismic events.
Bamboo is an evergreen plant native to Asia and America that grows at any altitude, even in sub-optimal climatic conditions. It is a very resistant natural resource and, thanks to its ability to capture a quantity of carbon dioxide 40 times higher than that absorbed by a forest of the same size, it also has numerous advantages for the environment. Bamboo is renamed “vegetable steel” because it is a natural resource particularly suitable for building construction. Bamboo is a great resource for green building: thanks to its rapid life cycle, which requires three to five years for regeneration (any other shrub employs at least fifteen), it is more suitable for a building market that is increasingly oriented towards safeguarding the planet.
11. Carbon fiber
Carbon fiber is a material “five times stronger than steel, twice as rigid, with a much lower weight.” The composition of the carbon fiber makes it flexible, allowing it to take on even extreme shapes and thicknesses.
Implementing it in the construction sector would bring enormous benefits both in terms of logistics, due to the streamlining of works on site, and for its effectiveness and efficiency; nevertheless, its features appear to be in line with the new construction trends, increasingly aimed at prefabricated buildings, which are faster to assemble. Finally, installing it is simple and does not require specialized labor.
Although it does not present itself as a true eco-sustainable product, carbon fiber could also reduce the environmental impact of the construction cycle. The next step will be to find a processing method and make it available in all respects in the construction field, then on construction sites. At the moment large machines have been used, too bulky for their actual use.
12. Photovoltaic cells
The solar photovoltaic does not produce heat, but is able to produce direct electricity, thanks to the use of special photovoltaic cells, based on the use of silicon, properly treated, whose efficiency can be variable depending on the technology used for their construction.
13. Unbaked clay
With the rediscovery of unbaked clay in green building it is possible to build healthy and comfortable environments, with the thermal-insulating and regulating properties of clay. With the green building and the spread of new disciplines such as bio-architecture, in the last few years ancient building materials have come back into fashion, fished from the world of nature, as it used to be. The current clay bricks have undergone numerous studies to improve the techniques and solve the main problems related above all to low mechanical resistance and to atmospheric agents. However, the low environmental impact is not the only characteristic of ecological bricks in unbaked clay. These materials also have high insulating power, both acoustic and thermal.
Furthermore, the raw earth acts as a regulator also on the internal humidity, improving the environmental comfort; absorbing odors and smoke, limiting the spread of electromagnetic fields. This affects the general well-being of the environment in which it is used. In Italy, it is forbidden by law to build entire buildings with clay bricks. However, even using it only in some parts, the improvement in performance is already evident, thanks also to modern production techniques.
We produce an enormous quantity of waste built with the most varied materials. Re-evaluate and re-use the secondary raw materials of the waste produced is an idea that future designers will have to take into serious consideration. Whether it’s turning cigarette butts into building materials for use in building compounds as a reducer of thermal conductivity or plastic bottles that turn into earthquake-resistant walls, recycling is something to be considered in a revolutionary way for architecture .
The creation of a passive thermal environment, protection from rain and total reconnection with the natural environment are just some of the things for which straw is effective. No wonder straw roofs were so popular in the past.
16. Organic materials
Organic materials focus on the harmony between man and nature and aim to create a balance between the built environment and the natural environment. These materials are made available by nature. In the building project the proportions must be logical also for the internal and external openings. Furthermore, it is better to avoid combinations of different materials and to organically incorporate the systems as interreactive elements in the building structure. In organic architecture, furniture must absolutely become an integral part of the building.
Frank Lloyd Wright is unanimously considered the founder of Organic Architecture. “Form and function are one” he claimed. In the writings he left us, he explained “for Architettura Organica I mean an architecture that develops from the inside out, in harmony with the conditions of his being, distinct from an architecture that is applied from the outside … work well for the cause of architecture … “
As with all materials, accessibility and cost play a huge role. There are certainly materials that are not on the list that would be the most obvious option in some parts of the world, so make sure you know the materials around you, plus these, and you’ll be sure to have a complete list of available resources.