An Irish BER runs from A1, the most energy-efficient rating, through A2, A3, the B, C, D, E and F bands, down to G, the least efficient. The rating estimates a home’s primary energy use in kilowatt-hours per square metre per year, based on features such as insulation, heating, windows and ventilation. You can search the SEAI register for an independent, registered BER assessor in your area to arrange an assessment or confirm a certificate. A BER rating alone does not guarantee a grant or a particular upgrade result, as eligibility and outcomes depend on the home and the relevant scheme rules.