- Display Energy Certificates (DECs) provide energy efficiency ratings for buildings based on actual energy consumption data and are intended to raise public awareness and encourage investment in energy efficiency. - DECs must be produced by certified assessors and applied to buildings occupied by public authorities or institutions that are over 1000 sqm in size and have heating/cooling systems. - The process for producing a DEC involves an assessor visiting the site, collecting energy and building data, and producing the certificate and advisory report which must be lodged with an authorizing body for a fee.