The concept of sustainable architecture has introduced a new approach to the design of homes and buildings that reduces their environmental impact both in the choice of materials used and during the construction phase.
The genesis of this approach can be traced to ‘building biology’ (or Baubiologie), a field of building science that originated in Germany in the 1970s. Among its founders was Karl Ernst Lotz, a pioneer of sustainable architecture, who in 1975 described the home as a “third skin” because the bio-ecological construction of a building must envelop us, protect us and be capable of “breathing”, i.e. enabling continuous interaction with the outside environment. The resulting structures are called passive houses, buildings created according to criteria that enable them to limit or completely eliminate the consumption of energy: very often they are powered by solar panels and are built out of wood, a material with both insulating and breathable properties.
Sustainable architecture: circularity
There are many factors that enable a building to be defined as sustainable:
- energy efficiency
- natural, recycled and recyclable materials
- the impact of the structure on the environment
- the use of water
Other factors of particular importance to the principles of building sustainability are the impact of the construction phase itself, as well as the disposal of materials. According to the Recycle Observatory Report by Legambiente (an Italian environmental organization – ed) on construction, one of the goals set for 2020 is a 70% level of recycling of waste materials, which should also encourage a circular economy approach in the decommissioning phase. As demonstrated by our Nuovi spazi dell'energia (New energy spaces), industrial facilities too can be redesigned using a circular approach, generating new development opportunities and creating value.
One circular construction site that set the bar in Italy was that of the Juventus Stadium in Turin, which was built using materials recovered from the demolition of its forerunner, the Stadio delle Alpi: 40 thousand square metres of concrete were crushed and reused to build the foundations of the new soccer stadium. In addition to reducing the use of new raw materials, the operation enabled savings of around 2 million euro.
The materials used in sustainable architecture
The attention to construction materials is central to the definition of a project as eco-sustainable. In addition to wood, other natural materials include cork, which is one of the best thermal insulators for construction, straw, which is pressed into blocks for its sound-absorbing properties, hemp, which, when combined with lime (another natural element), ensures thermal and sound insulation and a high resistance to fire. Recently researchers at Washington State University have created and tested a form of ecological polystyrene, a new plant-based material that can replace traditional polystyrene and that is more effective in terms of thermal insulation. This is a good example of technology at the service of sustainability.
Any assessment of materials must take into account not only their environmental impact but also the risks posed by earthquakes or fire, the presence of electromagnetic fields and potential concentrations of radioactivity in the ground.
Examples of high-energy efficiency buildings
When it comes to sustainable architecture, the most innovative solutions include energy efficiency and technological developments.
Another example from the sporting world is the velodrome constructed for the 2012 London Olympics. Londoners soon nicknamed it “The Pringle” on account of the similarity between the saddle shape of its roof and that of the famous brand of potato chip. The energy needs of the structure are minimal, as are its water requirements, thanks to a rainwater collection system.
Another case in point is that of the west building of the Berkeley Public Library in California, in which the air is heated and cooled entirely thanks to solar panels and special “chimneys” for natural ventilation that enable it to circulate without the need for air-conditioning units. Energy deriving solely from renewable sources makes the library an example of a Zero Net Energy building.
The advantages of sustainable architecture
The aspects that make sustainable architecture so attractive are the wellbeing of those who live in a home built according to these criteria and the economic savings.
An eco-sustainable building, in fact, brings undeniable benefits in terms of:
- Cost-efficiency (e.g. illumination from natural light)
- Commercial value over time
Current legislation also provides incentives for interventions that aim to increase energy efficiency of buildings. In May 2018 the European Council approved the revision of the European Directive (2010/31/UE) on this theme. Every member state is required to draw up a long-term strategy to support the refitting of national residential and non-residential building stock with the goal of making it decarbonised and highly energy efficient by 2050, thereby facilitating the cost-effective transformation of existing buildings into Nearly Zero Energy Buildings (NZEBs).
The best examples of sustainable architecture in Italy
But what are the best examples today in Italy? One of most recognisable buildings at international level is, without doubt, the Bosco Verticale (Vertical Forest) designed by Stefano Boeri in Milan, which in 2014 was named the world’s most innovative skyscraper. The two buildings near the Porta Garibaldi railway station, which are respectively 26 and 18 storeys each, house on their facades 900 trees, 5,000 shrubs and 11,000 perennial plants, located on the terraces arranged in an irregular pattern on the four sides of each tower. The concentration of vegetation corresponds to the equivalent of two hectares of forest. One of the objectives of the project was to enable nature to conquer new spaces in the city: the plant system of the Bosco Verticale helps in the creation of a special microclimate, producing both humidity and oxygen, absorbing CO2 and fine particles.
The Fiorita Passive House in Cesena, on the other hand, was the first apartment building in Italy to be certified by the Damstraat Passive Hause Institute, the international reference point for passive house standards. The building’s eight apartments are equipped with a single mechanical ventilation system and the building is not connected to the gas network: this construction, which is made of wood and metal has, for two years, been a symbol of Italian excellence.
Public spaces too are adopting the principles of eco-sustainability, beginning with schools. In Terento, in the mountainous region of Alto Adige, architects from an Austrian practice, Feld72, have built an infant school which, thanks to its materials, shapes and colours, fits perfectly with its natural setting, melding harmoniously with the Alpine skyline. In Sicily, in Caltagirone, the Piero Gobetti school is a zero-consumption building: thanks to a geothermal plant and photovoltaic panels it has become energy self-sufficient.
From the far north to southern Italy, sustainable architecture knows no bounds.