About a year ago, Bernd Rickermann from the association BELU Ugandahilfe e.V. contacted us with the request to develop a cement substitute for the production of mortar for building houses in Uganda. This exciting project immediately aroused our interest. Possible materials from Uganda were exchanged and their reactivity was investigated in our laboratories. A first small series of tests showed very promising results. The ash of Miscanthus grass shows a combined carbonate and pozzolanic reactivity, which can have a very positive effect on the properties of mortar. The compressive strength of lime mortar can also be increased by adding the miscanthus ash. Further cooperation in the field is highly desired by both sides and shows a high potential for climate-friendly construction.