This book gathers the latest innovations and applications in the field of resource-saving technologies and advanced materials in civil and environmental engineering, as presented by leading international researchers and engineers at the 5th International Scientific Conference EcoComfort and Current Issues of Civil Engineering, held in Lviv, Ukraine, on September 16–18, 2026. It covers a diverse range of topics, including ecological and energy-saving technologies; renewable energy sources; heat, gas, and water supply; microclimate provision systems; innovative building materials and products; smart technologies in water purification and treatment; protection of water ecosystems; and architectural shaping and structural solutions. The book, which was selected using a rigorous international peer-review process, highlights exciting ideas that will spur novel research directions and foster multidisciplinary collaborations.