We present a model of economic growth that bridges Green Growth and Degrowth perspectives. The model demonstrates that a minimum physical per capita consumption level can be maintained without recourse to tech-optimism, and moreover with degrowth in material resource throughput - respecting planetary boundaries. We critically discuss the assumptions necessary for this result, explore relaxing these, and illustrate that eventually a full transition to renewable energy and materials will be needed to sustain consumption levels in a post-growth economy. We identify areas for future growth modelling, emphasising that these require genuine interdisciplinary cooperation.