The ECO-SANDWICH® wall panel is an energy-efficient sandwich facade panel made of recycled and innovative materials. It was developed in collaboration by a group of Croatian scientific institutions and industry, led by the University of Zagreb, Faculty of Civil Engineering. The panel provides a possible technological solution for fast construction of energy-efficient buildings on a large scale, and is intended to be used in residential as well as commercial buildings.
To understand the environmental performance of the wall panels, the Croatian group of scientific institutes and businesses that developed them asked PRé to do a PCR-compliant LCA. The developers wanted to understand the environmental performance of the ECO-SANDWICH® wall panel, so they could communicate this when introducing the panel into the European market. A questionnaire was developed to gather the information needed for the study, which used leading sustainability software SimaPro to determine the impact of an ECO-SANDWICH® wall panel throughout its life cycle.
PRé conducted a life cycle assessment (LCA) to assess the environmental impacts of the ECO-SANDWICH® wall panels. Since the LCA followed the specific product category rules (PCR) described by the EN 158041 standard for building materials, the results of the LCA could be used to make an environmental product information sheet. The advantage of using the same PCR standards is that it makes comparing the LCA results of similar products easier and more reliable.
The study included the wall panels’ full life cycle, from cradle to grave. The results include the production stage, installation into a building, use and maintenance, replacements, demolition, waste processing for re-use, recovery, recycling, and disposal. A questionnaire was developed to collect inventory data from the ECO-SANDWICH® consortium. Information provided included amounts of materials, transport distances for the raw materials and (components of) the wall panel, energy or fuel required for specific processes. The following impact categories were included in the impact assessment: global warming, ozone layer depletion, acidification, eutrophication, photochemical oxidation, depletion of elements, and depletion of fossil fuels.
The resulting environmental product information sheet was reviewed by a third-party verifier. The results showed that the environmental impact of an ECOSANDWICH® wall panel is predominantly determined by the product itself – that is, raw materials, transport to production, and assembly – rather than e.g. installation on the building or the end-of-life stage. The total contribution of life cycle stages relating to product itself ranges from 48% for the impact category abiotic depletion (elements) to 84% for global warming. The figure shows that the contribution of the different raw materials to the impact of the product differs per impact category.
These results represent the current situation in Croatia. However, the panels can also be sold in countries where the recycling rates for mineral wool and concrete are higher. A scenario analysis showed that higher recycling percentages for mineral wool and concrete can reduce the environmental impact by up to 3%.
- The developers of the ECO-SANDWICH® wall panel gained valuable insight into the environmental performance and the hotspots of the wall panel.
- The environmental information sheet of ECO-SANDWICH® panels provides full product transparency and allows comparison to information sheets of similar products. This way, it can be used in business to business (B2B) communication to communicate the environmental performance of the wall panel.
- Opportunities for improvement by means of higher recycling rates at the end of life were illustrated, and can be used to stimulate actual improvements.