The future is hopeful, optimistic, courageous, and home to unbound possibilities. From this overly bright perspective, this paper describes the exploration of the uncertain future of sustainable architecture in the context of complex-adaptive systems. Applying the main currents of thought around foresight, systems-thinking and sustainability, the paper contemplates how futures-thinking might describe the future of sustainable architecture and recommends strategies and tactics. This design research highlights some critical uncertainties that could define the future of sustainable architecture. The paper explores these questions and describes six Key Design Tensions affecting the future of architecture. Afterwards, the paper offers innovation Strategies to Navigate Sustainable Architecture, these strategies fit well regardless of how the Key Design Tensions unfold.