The textbook "Characterisation prediction and reduction of energy consumption" by Mário David offers a comprehensive analysis of efficient energy use. It is aimed at readers interested in sustainable solutions to optimize energy consumption while saving costs. The author examines various environments to identify sources of energy waste and presents practical, cost-effective approaches to reducing consumption. By employing automated methods and raising awareness of energy efficiency, the book aims to promote both economic and comfortable solutions. The detailed investigation and proposed measures are designed to support sustainable and economical energy use.