05. Blueprint: life cycle

Article April 2021

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The environmental impact of the prefabricated renovation panels

The existing building stock plays an important role in the impact on climate and environment. Poor-insulated dwellings have a large heating demand, and typically make use of fossil fuels, leading to an important share of CO2-emissions and primary energy demand. As dwellings become more energy efficient due to installation of the INDU-ZERO renovation packages, the relative contribution of material use to the overall environmental impact of the dwelling increases. The extraction of raw materials and transportation, manufacturing and delivery of building materials, in fact, require a large amount of energy, water and land use causing environmental burdens. Within the INDU-ZERO project, the environmental impact of the renovation panels is analysed, and the materials with the highest impact are identified to minimise the impact as much as possible.

Life cycle assessment
The environmental impact of the renovation panels is evaluated by means of life cycle assessment (LCA). Each stage in the life cycle can be evaluated separately, from production stage through construction and use stage to end-of-life stage, in which materials are incinerated, deposited or recycled. As the analysis is conducted at product level, only the production stage is considered. This is also named a cradle-to-gate analysis. The production stage includes the extraction and transportation of raw materials, and manufacturing processes with regard to constituting building materials.

Choice of materials
The results show that the glass fibre polyester, OSB and EPS layer are the main contributors to the environmental impact of the original renovation panel. Therefore, the redesign of the renovation panels focused on these materials to limit the environmental impact. In addition, the choice of mounting mechanism also plays a dominant role. The high impact of the original mounting mechanism is related to the energy-intensive production process with regard to steel, but also to its high density leading to a high weight.

Reuse and recycling
Energy-intensiveness and weight are two key parameters that highly influence the environmental score. So, there are two main possibilities to reduce the environmental impact: reducing the overall weight of the system by changing the design or the material, or the energy-intensiveness of the production processes by making use of a material with a lower impact per unit weight. In addition, the lifespan and the possibilities for reuse and recycling of alternative materials are taken into account. In the project, different alternative mounting mechanisms are investigated in order to limit the environmental impact without affecting the circular potential in terms of reversible connections.

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Contribution: Yanaika Decorte and Marijke Steeman, Ghent University, Belgium