BREEAM In-Use is a science-based environmental assessment method used to measure, improve, and certify the operational sustainability of existing buildings, focusing on categories like energy, water, and waste. Within its energy performance criteria, BREEAM In-Use rewards buildings that reduce their carbon footprint by sourcing renewable energy, which is where Energy Attribute Certificates (EACs) - such as REGOs in the UK, GOs in Europe, or I-RECs globally - come into play. By purchasing and retiring these certificates, building managers can formally document that a specific volume of their electricity consumption comes from renewable sources, thereby helping the asset achieve higher scores in the Energy category and demonstrating a commitment to net-zero goals.