We present and validate a property-driven autonomous system that modifies its environment to achieve and maintain navigability over a highly irregular 3-dimensional terrain. In our approach we use decision procedures that tie building actions to the terrain model, giving rise to adaptive and robust building behavior. The building algorithm is driven by continuous evaluation and reaction to terrain properties, rather than relying on a structure blueprint. This capability is essential in robotic systems that operate in unstructured outdoor or remote environments, either on their own or as part of a team. We demonstrate the effectiveness of our approach by running a low-cost robot system that can build with compliant bags in a variety of irregular terrains.
