The present study provides a deep analysis and characterization of household electricity consumption in mainland Portugal through a cross-analysis of electricity metering data from January 2020 to December 2023 and responses to a 53-question energy survey. A sample of around 2,000 households was evaluated through different statistical approaches (multiple linear regression, machine learning, and hierarchical analysis). Key consumption factors were identified, including contracted electrical power, net surface area, and the presence or absence of electrical equipment. The results provide essential insights for defining targeted approaches and measures to enhance energy efficiency and improve household energy consumption behaviour.