This book collates important contributions from Engineering to Adapt (ETA2023). Eta, ?, the 7th letter of the Greek alphabet, is scrupulously used to denote efficiency and this is what ETA2023 strives for. In context, efficiency, ?, is about avoiding waste, may this be energy, time, money, or material, in accomplishing something useful. As such, ETA2023 aims at bringing experts and future leaders together to forge more efficient ways to engineer and live. In other words, ETA2023 strives to synergise and catalyse all stakeholders, enthusiasts, and experts from academia, industry, policy arenas, and the general public, to formulate novel ways to improve tomorrow. This symposium will disseminate recent progress and promote collaborations to maximize opportunities for innovative integrated solutions. Topics of interest include resource and energy efficiency, waste reduction, and eco-friendly agriculture, architecture, engineering, and living.