Integral design
The chair of Innovative Structural Design (ISD) focuses on the basic knowledge and understanding of structural principles, in combination with specific materials properties, in order to develop innovative and sustainable structural design solutions. One of the group’s key goals is the study of the integral structural design process and the relationship between architecture, structural design and other building-related disciplines.

Resource-efficient structural design
The building and construction industry are by far the most resource-intensive sector in the European Union. This sector, which is based on a very strong responsibility of architects as well structural engineers, consumes approximately 50% of all primary raw materials and is, therefore, substantially exhausting natural resources. In recent decades the construction industry focused mainly on the reduction of buildings’ energy consumption as well as use of renewable energy. However, the impact of material use will also be in the spotlight in the future.

Recently the Dutch government formulated the program ‘Nederland Circular in 2050’, which states the ambition to use 50% less primary materials in 2030 and to have a full circular economy in 2050. As one of the consequences as of 1st of January 2018 the Dutch municipalities will check compliance with a so-called MPG calculation (in Dutch: MilieuPrestatie Gebouwen; in English: Environmental Performance Buildings) for all new buildings. This mandatory material impact evaluates the total effect of the weighted environmental impacts of the total building’s materials. To meet these ambitions, resulting from the Paris Climate agreement, it is essential to re-think the use of materials in structural systems. Various approached can be followed. ISD focuses on the following three.

Reduce – Reuse – Renew/Recycle

1. Reduce use of materials:

The optimisation of structural systems in terms of minimal weight as well as more recent developments in the field of adaptive structures will create new opportunities to minimise the use of natural resources even further.

Lightweight Structures: Lightweight structures fully integrate engineering and architecture. When structures must span larger distances, or be higher, deployable or mobile, reducing their self-weight becomes increasingly important. To achieve this, lightweight structures avoid bending moments and are structurally designed to develop internal axial forces (tension and compression). Three-dimensional natural shapes make the flow of forces visible and enrich the architecture.
Adaptive Structural Systems: A variety of design aspects influence building performance. These include, apart from structural loadings, architectural criteria, environmental impact and user behaviour. Most, if not all, of these aspects change over time. However, conventional buildings are not designed to adapt to contextual aspects and needs. Therefore, research focuses on instant adaptation of structures and building envelopes to facilitate adaptation to context and needs.

2. Re-use of materials, elements and structures:
In all industrial countries there is a huge amount of existing building stock. Even if there will be further need for new buildings, a good understanding of the potential to re-use existing buildings can also contribute to save natural resources.

Life Cycle Design of Structures: To achieve the high European and Dutch sustainability goals, existing and future building stock energy performance levels will need to improve drastically. Furthermore, to reduce CO2 impact, it is necessary to systematically evaluate buildings’ capacity for change and upgrade them. This requires an assessment methodology to implement an improved Service Life. This methodology must incorporate statistical survival analysis methods as well as rating methodologies for technical flexibility indicator.

3. Renewable materials:
Another possibility is to replace traditional (mainly cement-based) materials with renewable bio-based materials, or even use completely ephemeral materials, such as ice, for temporary buildings.

Bio-based materials: Obviously natural, bio-based materials such as timber and bamboo have been used throughout these times, but nowadays other materials, which are not necessarily new themselves, but their application for building products are new, came up. Examples are hemp and flex fibres, Mycelium or lignin-based fibres for composite materials. In addition to fibre a resin is required to create composite materials and structures and various bio-based sources exist, such as linseed oil, furans or cashew nut shells, although the commercial development of these materials is not very far yet.

Structural ice: Furthermore, water, respectively ice, are being studied as a possible construction material. In certain areas, supply is practically endless, although its application for buildings is obviously limited to regions with very specific climate conditions. By reinforcing ice, it becomes stronger but also more ductile. A new application based on the unique deformation properties of reinforced ice is the use of flexible mouldings of ice.