Carolin Volk and her husband Holger leave Nuremberg for Burgenland, Austria, to build a house made entirely of straw, wood and clay, materials sourced locally and biodegradable at the end of their life. The film follows their project through delays of more than a year, rising costs and a shortage of craftsmen trained in these techniques. In Žalec, Slovenia, Andrej Fideršek takes a different route, renovating an old town house using only second-hand materials in line with circular-economy principles, work that won him the European Bauhaus Prize, though even he ends up making compromises. Construction experts interviewed throughout argue that the greenest building is often the one that already exists: renovation saves more CO2 and resources than any new eco-friendly build, and they call for regulatory changes to make conversion cheaper than demolition. The film mixes on-site footage of both builds with expert interviews to weigh idealism against the practical costs of building differently.