The explosion of the Tiny House Movement in recent years demonstrates the bourgeoning popularity of sustainable living practices in the United States. However, there has yet to be an in-depth guide illustrating financially-conservative and environmentally-sensitive methods for doing so. To address these gaps in public understanding, Project EARTH (Environmental Action Research for Tiny Homes) will explore the viability and feasibility of tiny house construction. Guided by the ‘doughnut economics’ of sustainability design and ecological limits, this action research project presents a solution-focused and highly practical application for influencing the growing trend of tiny house construction in the United States.