Software systems meant to support older adults often are not well accepted as they do not meet the expectations and requirements of the target group. An involvement of older adults in system design seems imperative. The project ParTec investigated and evaluated techniques for participatory software development with regard to their suitability for communication and equal cooperation with older adults. With a group of 15 retirees we developed concepts for an online neighbourhood platform. Using various participatory techniques researchers and participants developed a deep common understanding of everyday life in early retirement, determined requirements and co-created design ideas and concepts. We will show that the use of cultural probes with subsequent qualitative interviews forms an ideal starting point and a strong fundament for a participatory design process with older adults.