The En­vi­ron­men­tal Res­pon­si­bi­lity of Ci­vil En­gi­nee­ring

Testo in italiano al seguente link 

The growing demand for new infrastructure, combined with the need to redevelop existing buildings and preserve works of significant material and historical-cultural value, presents civil engineering with complex challenges that, at first glance, may appear new, but which in reality have always been at the heart of design work. Civil engineers have always been called upon to provide effective and functional solutions that meet the needs of society.
Their role has traditionally been defined as that of rational builders, responsible for ensuring the stability, safety and functionality of structures through the efficient use of available materials and resources. In the past, sustainability, although not explicitly formulated as an autonomous concept, was implicitly present in the pursuit of durability, economy of means and structural adequacy.
The construction industry is one of the sectors with the greatest environmental impact, with significant effects on the consumption of natural resources, waste production and emissions linked to the production of materials and construction processes. In this context, the role of the civil engineer takes on strategic importance. Civil engineers are called upon to consciously and systematically integrate the principles of sustainability into the design and construction of works and infrastructure, with the aim of optimising the use of resources, reducing environmental impact and ensuring compatibility with the natural and social context.
Upstream of all this, the commitment to sustainability takes the form of active involvement in strategic decision-making processes, from the allocation of resources and land management to the protection of natural and built heritage. Their contribution is also decisive in contexts where regulations, standards and guidelines are developed to support professional practice, while ensuring the necessary space for innovation, an essential driver of sustainability.

The Swiss Sustainable Building Standard (SNBS): a holistic approach

In order to effectively support the process of sustainable design and construction, numerous tools have been developed in recent years in the form of standards, directives, IT support, scientific publications and guidelines¹. However, these tools are only fully effective when incorporated into a design process that is conceptually sound, open and capable of constructive dialogue with other disciplines.
SNBS stands out from other labels for its holistic, goal- and results-oriented approach, which is applied to the entire life cycle of the building. It covers buildings, neighbourhoods and infrastructure, from the design phase to demolition or planned renovation. SNBS “Building” and SNBS “Neighbourhood” integrate and refer to the Minergie standard, which, however, focuses mainly on energy aspects and living comfort and, consequently, on issues such as thermal insulation, building technology, the use of renewable energies and the reduction of emissions.
In addition to these areas, the SNBS standard offers a broader and more comprehensive concept of sustainability, including the positioning of the building and its integration into the local and environmental context, as well as consideration of the social and economic impact of the project.
SNBS “Infrastructure” is currently still in the development phase and is based on SIA Standard 112/2 “Sustainable Construction – Civil Engineering and Infrastructure”².

Designing according to the SNBS standard for civil engineers

Sustainability assessment according to SNBS is divided into three main areas: Society, Economy and Environment. Each area is subdivided into themes, criteria and indicators. The assessment process produces a certification level, which allows different projects to be compared and the overall quality of the intervention to be made explicit. In this way, the standard serves both as a certification tool and as a support for design and design decisions. The three areas are analysed briefly below with reference to the SNBS “Building” standard from the perspective of the civil engineer.
The “Society” area covers general topics such as accessibility, overall well-being and the quality of the intervention and use. The contribution of the civil engineer in this area may appear marginal; however, their role as a consultant and active participant in conceptual design is fundamental in defining the structural and functional foundations necessary for the development of a sustainable project.
In the “Economy” area, the criteria require more direct involvement in the design. These include elements relating to the life-cycle costs of the project, the possibilities for dismantling and reuse, natural risks, the accessibility of technical installations, and the important aspect of the flexibility and versatility of the building, which require a central contribution from the civil engineer.

However, civil engineers seem to be able to exert the greatest influence in the “Environment” area. In this context, a number of aspects are analysed which, according to current common sense, determine unequivocally whether a building can be considered virtuous from a sustainability point of view. These include greenhouse gas emissions, energy requirements for construction and the use of materials defined as ecological. It is important to note that, according to the description of the SNBS-Hochbau³ criteria, the criterion relating to materials, entitled “Resource savings in the materials used”, only considers wood and recycled concrete as environmentally friendly materials. Unlike the Minergie ECO standard, the use of low-clinker cement, which would have a lower environmental impact, is not considered for concrete. In the context of the assessment of building materials, there is also considerable scope for future expansion and refinement of the criteria adopted.
In light of the above, it would appear that the path leading to the design and construction of a building deemed sustainable is not predetermined. Analysis of the proposed requirements reveals a certain interdependence between them, which may in part hinder their full and simultaneous fulfilment. A few examples can clarify this dynamic. A structure built with environmentally friendly materials, in a specific context, may not be the most efficient solution in terms of the quantity of materials used or greenhouse gas emissions. Similarly, a flexible and generous structure, designed to allow for easy reorganisation of spaces and future conversion, is not necessarily compatible with reduced grey energy use and low emissions. Similarly, construction systems aimed at minimising materials, such as ribbed slabs or wooden beams combined with secondary elements, may prove less favourable in terms of the integration of systems and flexibility of use over time.
According to the SNBS standard, the assessment therefore tends to reward a certain versatility and multifunctionality of the structure. In this context, radical or strongly targeted choices, for example in the selection of materials or structural typology, risk penalising the overall sustainability assessment compared to a more balanced and considered approach. However, this should be an incentive for those who view the new standards with scepticism: the potential to pursue sustainability objectives without resorting to ready-made solutions or substantial additional economic investments is indeed real.
In any case, it is clear that, even with pre-established assessment criteria, there is ample scope for seeking alternative, innovative and unconventional solutions. However, this presupposes that the assessment parameters are also capable of adapting and evolving over time, in line with the principles of sustainability.

General considerations on the role of civil engineers in the era of sustainability

• Buildings are gradually transforming from architectural and static works into complex machines or systems, consisting of a multitude of components often characterised by a limited lifespan. In this context, the functionality and rationality of the structure occupy a central and fundamental place in the design. From this perspective, the role of the engineer remains, today as in the past, fundamental.
• What at first glance might appear to be a sort of “call to arms” is in fact a reminder of the original values of engineering. The engineer's working methods are, by their very nature, oriented towards sustainability criteria; however, in the contemporary context, the possibilities for intervention have expanded and design impulses have intensified, increasingly extending to the ecological dimension. Building or renovating involves mortgaging space and is, in itself, an act that should first and foremost prompt a profound awareness on the part of the designer and translate into design choices that are consistent with the specific context and capable of generating value over time. This contribution is crucial for the creation of truly sustainable works.
• When considering sustainability, it is essential to view the built heritage as a resource that can contribute not only to limiting the occupation of new land, but also to reducing the waste of raw materials and emissions associated with construction⁴. Civil engineers assess the existing heritage and help to interpret it from a new perspective.
• The client's commitment is fundamental and pays off over time. The choice to carry out a high-quality project, with a high level of user comfort, developed and executed according to sustainability criteria, increases the material and immaterial value of the work. By relying on an interdisciplinary group of qualified professionals, or by selecting them through structured procedures such as study mandates or design competitions, the client ensures a safe, lasting and resilient investment.
• There are also conceptual, social and urban planning aspects that belong to a higher level in the hierarchy of design processes, aspects that the SNBS standard explicitly considers. Sustainability is now an essential element and must be recognised as such. In this context, however, it is essential to avoid the risk of overturning the design logic by adopting a priori imposed or standardised solutions. A truly sustainable building is one that will be recognised as valuable over time, a building that no one would ever feel the need to demolish.

References

1. NNBS. 2021. SNBS-Hochbau: Landkarte, Standards und Labels nachhaltiges Bauen Schweiz. Netzwerk Nachhaltiges Bauen Schweiz.

2. SIA, Schweizer Ingenieur- und Architektenverein. 2016. SIA 112/2, Nachhaltiges Bauen – Tiefbau und Infrastrukturen. Zürich, Schweiz.

3. SNBS. 2024. SNBS-Hochbau: Kriterienbeschrieb – Nutzungsarten Wohnen, Verwaltung, Bildungsbauten, Ge-werbenutzung im Erdgeschoss. Standard Nachhaltiges Bauen Schweiz.

4. Muttoni A., 2025. Understanding Ticino's industrial past in order to better redevelop and enhance what remains. Presentation given at the VII SIA Ticino Study Seminar, Revitalisation of industrial heritage for new urban scenarios, SUPSI, Mendrisio, Switzerland.