Choosing the right con­struc­tion products

Choosing sustainable construction products plays a key role in achieving the climate action goals of the Paris Agreement. This is because, in addition to the operation of buildings, so-called grey emissions are already produced during the manufacture of the materials used. And throughout the further life cycle, greenhouse gas emissions are also caused by the replacement and recycling or disposal of the building materials used. In the course of the political, social and economic climate action debate, the focus is therefore increasingly on building products, their manufacture and the associated carbon emissions.

With regard to the choice of materials, it is not enough to pay attention to their carbon footprint alone. The question of reuse and recyclability is also important in order to save resources. Or the question of substances that could be harmful to health and the environment. It is also important to clarify whether a construction product has been manufactured according to standards that are socially and environmentally acceptable. These are questions that require rethinking on the part of the construction industry, as well as proactive requests from planners to the manufacturing companies. But even with all this relevant information about materials, it is still up to the planners to get it right. And that means selecting building materials in a way that contributes to a sustainable building.

The DGNB has published a report on the subject in order to provide more clarity on what is important when choosing sustainable materials:

The consideration of construction products in terms of sustainability is also one of the central themes of the DGNB Certification System. For around half of the DGNB certification criteria, construction products have an impact on the result and thus on the overall performance of a building. In order to be able to assess the influence of building products, the DGNB carries out a project-related assessment. This means that the certification system is designed to assess products in the context of the building, rather than focusing on the sustainability of individual products.

The DGNB distinguishes here between a direct influence and an indirect influence within the various criteria.

• Direct impact: Qualitative and quantitative features/properties of a concrete product within the construction context.
• Indirect impact: Planning-based services in relation to construction products (defining environmental requirements for construction products in the tender phase) or methods of resolution which can be implemented either through planning or also through the concrete product selection (for example, reducing potable water consumption through the greywater utilisation or water-saving fixtures).