Viktoria Arnold, researcher at BTU Cottbus – Senftenberg, Germany

The assessment of the sustainability of buildings has been increasing rapidly in recent years. This is not only related to the international goals of the United Nations, which are set out in Agenda 2030[1] and include global ecological, economic and socio-cultural aspects in the building sector (SDG 11[2], 12[3] and 13[4]). It is also linked not only, but in large part, to the national goals of the United Nations, which each country has set for itself. Germany, for example, has set a goal of achieving greenhouse gas neutrality in its building stock by 2050[5]. Different countries have different requirement methods. Some countries have made it mandatory to submit a so-called Climate Declaration for future building during the approval phase and to comply with certain limits for greenhouse gas emissions, such as the Netherlands, Sweden and Finland. Other countries, such as Germany, subsidise climate-friendly construction and renovation measures. Some builder-owners are just interested in building sustainably and climate-friendly and want to know what design decisions, building products and materials have what impact on the environment. And what contribution the building as a whole makes to resource and climate protection during its entire life cycle. To find this out, many sustainability assessment systems for buildings are used, which have LCA (Life Cycle Assessment) as one of the most important criteria. The basis for LCA is the EPDs (Environmental Product Declarations) based on ISO 14025 and EN 15804 for the different building products and materials. The more building products and materials have an EPD, the more accurate the calculation of the environmental impact of a building. This will greatly assist the builder-owner when deciding on certain construction and architectural solutions, and what contribution the building as a whole makes to resource and climate protection throughout its complete life cycle.

I am doing my doctorate at BTU on sustainability assessment of single-family houses. For such buildings, which are nowadays a luxury from a climatic point of view, such an assessment is particularly important.

In the ReCreate project, our German Cluster is particularly responsible for work package 6 “Energy and Climate”, which aims to evaluate the environmental and economic impacts (LCA and LCC (Life Cycle Costing)) of the reuse of precast concrete elements. Our major objective is to produce one or more EPDs for the precast concrete elements (ceiling, exterior and interior wall) suitable for reuse. This will enable LCA for new buildings with the reused elements and distinguish such resource and climate-friendly projects from others. Several previous research projects led by Prof. Angelika Mettke[6] have shown that the reuse of concrete building elements can significantly reduce the carbon footprint and energy consumption in the product phase by up to 93-98% compared to new production[7].

We notice again and again in our research that reuse can only be possible if the parts are still considered in the installed condition and the careful disassembly is carried out by an experienced company in the best case. Recently, the new DIN SPEC 91484[8] has been published, which is the basis for evaluating the high-quality connection potential for building products before demolition and renovation works where Prof. Mettke has been involved. Another prerequisite for successful reuse is that the building documents are available and, if possible, up to date. This is rarely the case with existing industrially constructed buildings that are up for deconstruction. That is why today’s initiative on the building resource passport is very important, where all building materials and products used, as well as their quality and recyclability, are recorded and kept up to date. It is also important to look now at what can be used to build more sustainable buildings so that the new building can be reused later at the end of its life cycle.

I am asking all these research questions in my doctoral thesis because it is still not so far that one comes to the idea of building a single-family house from used precast concrete elements.

[1] Sustainable Development Goals

[2] SDG 11 Make cities inclusive, safe, resilient and sustainable

[3] SDG 12 Ensure sustainable consumption and production patterns

[4] SDG 13 Take urgent action to combat climate change and its impacts

[5] Deutsche Nachhaltigkeitsstrategie Weiterentwicklung 2021, p. 103

[6] Structural Recycling Unit, Faculty 2 of Environment and Natural Sciences, BTU Cottbus – Senftenberg

[7] Mettke, A. (2010). Material- und Produktrecycling – am Beispiel von Plattenbauten. Zusammenfassende Arbeit von 66 eigenen Veröffentlichungen, Cottbus, Techn. Univ., Habil.-Schr. p. 235–243

[8] DIN SPEC 91484:2023-09 “Procedures for recording building products as a basis for evaluations of connection use potential prior to demolition and renovation work.”