Overview

Steel and concrete are the most widely-used construction materials around the world, but producing and using them in construction produces high levels of carbon emissions. So how can we build the cities of the future in a more climate-friendly way? In this, using organic materials or recycling and reusing materials are promising approaches. This was the outcome of an international event held by Connective Cities in Potsdam from 13 to 15 November 2023 in partnership with the City of Potsdam as State Capital of Brandenburg, Bauhaus Erde and the Potsdam Institute for Climate Impact Research (PIK).

Keynotes

Prof. Jürgen Kropp from Bauhaus Erde and PIK showed how climate change is affecting cities around the world and causing issues such as increased numbers of hot days. Climate-friendly construction methods using wood and recycled materials could help reduce heat build-up and also reduce carbon emissions from the construction industry, according to Prof. Kropp.

Dr Susanne Winter, who manages the Forests programme for the World Wide Fund for Nature in Germany was joined by Pete Heuer, the chair of Potsdam City Council, to warn against the over-consumption of regrowable raw materials and call for wood used in sustainable construction to come from sustainably managed forests. In this, they argued, we need to find a sustainable balance between protecting and exploiting forests.

In a talk on changing preferences for construction materials in the Hindu Kush region, Erica Udas from the International Centre for Integrated Mountain Development (IDIMOS) in Nepal spoke about the “terrorism of concrete and steel”, particularly in reconstruction following the major earthquake which hit Nepal in 2015. She described how these were displacing traditional sustainable construction methods and generating a large carbon footprint.

Results

The general tone of the conference was that bringing about a sustainability transformation in the construction industry was not easy, but there were many promising approaches. The first step is to ensure that organic raw materials are available in adequate quantities, such as wood from sustainably managed forests. In many places, participants agreed, this would mean breaking down outdated ways of thinking. Representatives from Asian countries reported that people prefer steel and concrete as modern construction materials and ignore the benefits of materials such as wood. In Germany building codes are planned to make it easier to re-use materials.

Participants also stressed that making the construction industry more sustainable would require forging new alliances and thinking outside the box. Industry, politicians and administrators would need a new business model to make use of regrowable and recyclable materials in construction, based on robust data and analysis. A future scenario of this kind could be developed by sharing examples of good practice and innovative ideas. However, the general public will also need to be convinced of the benefits of more sustainable construction, in addition to introducing new or updating existing legal and policy guidelines.