Climate protection and the geopolitical situation pose major challenges for our society. To protect the climate, we must reduce CO2 emissions and cut the consumption of fossil energies. The war in Ukraine makes us very aware of our economy‘s dependence on fossil energies and their availability and costs. This makes savings even more urgent than they already have been before. Likewise, the relevance of supply chains and availability of raw materials is becoming more and more obvious – also for the construction industry. An optimization of the design of conventional tunnels by owners and planners can lead to a significant reduction in CO2 emissions, energy and raw material requirements, and thus also in cost. In the article, potential optimizations are shown and explained with the help of examples.