How DECs Are Rated
DECs use an operational rating system from A (very efficient) to G (inefficient), based on actual energy consumption data. The frequency of renewal depends on the building’s size:
- Buildings over 1,000m² require an updated DEC every year
- Buildings between 250m² and 1,000m² require a new DEC every 10 years
This rating system enables building owners to track performance over time and identify opportunities for improvement.