Ecological dimension

The building sector is a major determining factor in sustainable global development, because it has a marked influence on the contamination of the environment and because, in the long term, it has a high optimisation potential. For example, the construction and functioning of buildings account for around 35% of the total consumption of primary energy in our society; building activity generates 50% of the volume of waste products and about 27% of carbon dioxide emissions.


Economic dimension

It has been calculated that 82% of capital tied-up at a global level is invested in real estate. In Europe, for instance, people spend about a third of their income on the home. We can see just how important the economic dimension of green architecture has become on an international scale, from the fallout of the present financial and economic slump. This began in the United States with the subprime mortage crisis in the ambit of property financing, in this case the granting of credit to clients with a weak or very weak solvency. Thanks to these credits – enormous sums (valued at US$9,865,000,000) were invested in real estate whose financing was not sufficiently guaranteed. As long as the prices of the properties rose, thanks to an artificially generated demand, the financing was seemingly guaranteed by the increase in the value of the real estate that had been financed. While part of the responsibility can be attributed to the credit institutes, this warped development was encouraged equally by investors, construction companies, architects and buyers through the unregulated building of new properties.


Sociocultural dimension

Buildings are important elements that give character to cities, define public and private spaces and determine the look of the urban setting as much they do the social relationships between the various groups of society. They encourage social processes. They make them possible or impede them. In this regard, the sociocultural effects of building activity are various and manifold: the city defines the spaces that its inhabitants will use, either individually or in groups, as vital public or private spaces. The constructed environment shapes the cultural identity: buildings can be important cultural vehicles, exerting influence through their visibility (unlike other cultural products, buildings are always visible) and their endurance in time. We are not only talking about typical historical buildings, which in many cases are the very symbol of a city, but also modern edifices that characterise the identity of a metropolis or an area. The Guggenheim Museum Bilbao is an example of a single building that has become the symbol of the cultural renewal of an area. The persistence of such icons lies in their integrative action, which is able to create a sense of identity.


Sustainable architecture as a system of thought

The various and diverse themes and aspects related to greater sustainability in the building sector are codified in a series of criteria. These criteria should provide investors, city planners and architects with the necessary indications regarding the important aspects of constructing a sustainable building and the principles to be respected regarding each single aspect. As well as the usual design tools, there exist certification systems that make it possible to analyse buildings and projects from the point of view of sustainability. If a building respects the sustainability criteria it is certified and, in the case of a particularly positive evaluation, is awarded a silver, gold or platinum rating. Certifications of this kind include the American LEED™ (Certificate in Sustainable Architecture), the British BREEAM Certificate and the German DGNB Zertifikat (Deutsche Gesellschaft für Nachhaltiges Bauen). These systems enable an overall vision of the requirements, deconstructing the general concept of green architecture and defining binding regulations. A further advantage offered by certification is the possibility for investors and landlords to put forward the integration of the sustainability system as a marketing argument, making it a strong selling point. This gives investors an incentive to seriously consider sustainability criteria, which are often dismissed as an ideal that is only good for raising costs.

Sustainability is seen often as a technical requirement for a building, but it is already an important prerequisite at the city planning level. Within the sphere of post-war urban development, the building and expansion of many cities resulted in the occupation of vast surface areas and produced a high volume of traffic. Traffic pushes up costs and requires investments and infrastructures such as road systems and cars; it is damaging to the environment, since it increases carbon dioxide and fine dust emissions. Last but not least, traffic is socially unsustainable, since the roads and areas occupied by moving and stationary vehicles can no longer function as vital spaces; moreover, it generates noise and stress and is incredibly time consuming. It is basically a problem deriving from the structure of the city. An important indicator in this regard is urban density, which implies a consequent inverse exponential growth in energy consumption. A dense and compact urban fabric enables greater independence from both public and private transport, since people can move from one place to another on foot or by bicycle. Moreover, workplaces, shops and social structures like schools and kindergartens are nearer to residential districts, making many longer journeys unnecessary. Another advantage is that a more compact form of urbanization has fewer surfaces between which thermal energy is exchanged and, consequently, the energy consumption is lower. High urban density has yet other benefits: for instance, in a city centre many different architectural styles, building typologies and functions overlap, creating a rich array of shapes, colours and spaces. This kind of fabric acts as a cultural stimulus and offers a whole variety of vital spaces, and also diverse life styles, to inhabitants. Centralized European cities represent an excellent model for the sustainable city of the future, because their urban density and variety ensure their long-term usability.

Buildings themselves are often planned in an aspecific and modular way. The majority of buildings erected in the second half of the 20th century were mono-functional. These constructions do not relate in any way to the urban setting. Their architectural structure and configuration complicate or prevent their being adapted for new uses (such as the reconversion of office buildings into residential ones) or new needs (larger housing units, housing adapted to the requirements of the elderly or the disabled, new bathrooms). They do not constitute, externally or internally, spaces that the users can make their own. Neither residents nor passersby can identify sufficiently with these buildings, giving little hope of long-term maintenance.
The building sector plays a considerable part in this overall consumption and, due to the large number of pre-existing elements, also has the greatest potential for making a quantum leap in energy saving. Now that the so-called “Passive House Standard” is applied in many cases, energy consumption is equal to approximately a tenth (c. 15 kWh/mq*a) of the European average (c. 150 kWh/mq*a).


Dynamic planning

Today there are many possibilities and solutions regarding certain aspects of green building. The incorporation of all the individual aspects into a systemic thought process that considers the effects on other sectors and seeks to optimise them at the global level, is of fundamental importance in achieving sustainable development. In this regard, it is primarily architects and planners who are asked to assume greater responsibility. Unlike engineers, who are nearly always concerned with purely technical problems governed by precise methods, architects are constantly caught between “hard” facts, and as such quantifiable (statistics, costs, energy consumption), and “soft” facts, namely sociocultural aspects such as creative design, use suitability and identification with buildings.

For today’s architects the difficulty lies in having to integrate a wide range of interdisciplinary aspects into the design process, something that, so far, not many of them do, choosing to stay with traditional forms of design that are linear and aimed at a specific function. Rather than as a complex process, a project is often seen as an act of artistic creation based on an idea (brilliant) that determines the finished building right down to the last detail. Since most of the aspects of sustainability are verifiable while work is in progress and later on the basis of the results, interactive and recursive design methods which permit the decisions that underpin them to be rethought, must become the norm.

The structure of a building must be adaptable to future uses. It is also important that not only construction but also maintenance, reconversion and refurbishment be taken into consideration when new buildings are designed. Technical progress makes it necessary to replace architectural elements (windows, claddings) or apply innovative techniques (central heating, cooling systems, sanitary ware) at shorter intervals. It is advantageous to provide for interchangeable architectural elements and systems. Even buildings have a shorter life-expectancy rate. That’s why we should consider not only the construction process but also its reversibility and the reyclability of the materials adopted. Thus, visible and reversible links and separable materials of homogeneous composition, are necessary for the differentiation and recycling of raw materials.
That sustainability cannot be seen as merely a technical requirement can never be stressed enough. Formal aspects and suitability for a flexible and heterogeneous use are also very important. In the first place, buildings must offer a living or work environment that is pleasing to users. Rather than a technical problem, this is an extremely complex requirement. Buildings establish a vital dialogue with the surrounding environment; they are closely linked to the flow of energy and material; they change in the course of time. That is why they must be conceived and developed according to these aspects.