The European Union’s construction industry stands at a crossroads: In its transition to a climate-neutral ecosystem, the incumbent industry is worried that organic replacements are given disproportionate support. Construction is a big business. According to European Commission data, the sector employs around 25 million people and generates an added value of €1,158 billion per year. On the flip side, construction is responsible for 50% of material use and about 35% of waste and emits about one-third of the EU’s total CO2 – both during construction and when the buildings are lived in. Tackling this two-sided construction and buildings challenge is very much on the mind of Brussels policymakers. In March, the Commission presented its “transition pathway for the construction ecosystem,” laying the foundation for the sector’s eventual digital and green transformation. The Brussels push is accompanied by initiatives like the New European Bauhaus. No one knows what this transformed sector, future houses, will look like. Some experts say houses will become Lego-like material repositories, and traditional environmentalists eye a future where wood plays a bigger role. The prospect of being replaced by wood-based materials has the traditional mineral construction product industry – think concrete, ceramics, cement and mortar – rather worried. Such products make up about 5% of the worldwide total greenhouse gas emissions, more than double that of the global container fleet of 6,000 huge ships, the backbone of international trade.

Today, cement is said to be the second most-often consumed product, beaten only by water. But production of cement is damaging to the climate as it is ultimately dusted limestone and clay heated to temperatures as high as 1450 °C. Generating that heat to force carbon out of the raw materials produces extra carbon, while also deeply altering their chemical bonds, creating “clinker”. The changes leave clinker extremely ready to form strong structures when mixed right, forming concrete with widespread application in construction. ....