The built environment is increasingly shifting from a focus on “less harm” toward regenerative design - where buildings actively contribute to the health of people, ecosystems, and material cycles. This is the first in a three-part Lean In series exploring regenerative materials and the role of specification, research, and design decision-making in enabling this shift in practice. Across the series, speakers will examine how architects and designers can rethink material selection through the lenses of human health, carbon, circularity, and ecological regeneration. Part 1 reframes material selection through the lens of human and ecological health. It explores how everyday specifications impact indoor environments, supply chains, and ecosystems — and what it means to move beyond “low toxicity” toward regenerative materials that actively contribute to ecological and human wellbeing. Join Martha Lewis (Henning Larsen) and Nicola Smith (Living Future Oceania) as they discuss the evolving role of architects and designers in shaping healthier built environments, the opportunities and challenges of specifying healthier materials, and how regenerative thinking can reshape the way we understand sustainability in practice. Each session will prioritise practical insights and clear takeaways, enabling participants to apply learning directly to their projects and practice and to consider ‘What should I do differently on Monday morning?’.