After years of research and development work, the German Overath-based family-owned company Metten Stein+De- sign presents EcoTerra Zero, a concrete block that is 100% free of cement. Thanks to the special production technology, up to 75% less CO2 per square meter of paving is emitted with a block thickness of 8 cm - and, according to the manufacturer, with the same load-bearing capacity and service life.