Building Energy Rating (BER) explained in simple terms

A BER or Building Energy Rating is an objective scale of comparison for the energy performance of a building ranging from A1 to G. It is rather like the the A to G rating for a household electrical appliance like your fridge. A-rated homes are the most energy efficient and G the least efficient. A BER certificate will be compulsory for all dwellings being constructed, rented or sold after 1st January 2009.

BERs will be carried out by specially trained BER assessors, registered by Sustainable Energy Ireland (SEI). Only Registered BER Assessors can carry out an official BER assessment and it must be submitted to SEI for publication on the national Register of BER Assessments. Registered BER Assessors have successfully completed a validated BER training course and exam provided by an accredited training company.

The official method for carrying out a BER for a dwelling is the Dwelling Energy Assessment Procedure (DEAP). It consists of step by step calculations within a series of individual modules. The modules deal with ventilation, heat losses, domestic hot water, internal heat gains, solar heat gains, mean internal temperature, space heat use, space heating requirements, total energy use and fuel costs, energy emissions and costs. The calculations emerging from these modules are combined to produce an overall calculation of annual energy demand and CO2 emissions. The dwelling is then given a rating on a scale of A1 (best) to G (worst). A detailed account of the standard BER procedure for Ireland is set out under the heading ‘DEAP’ in this web site.

The DEAP methodology is based on standard occupancy assumptions and a range of technical judgements based upon the views of various expert organisations regarding the energy efficiency impact of various building components and attributes. In practice the energy efficiency of a building will depend on how the occupants operate the building. The BER for a dwelling may change over time due to many factors including deterioration or modification to the fabric of the building, changes to the heating systems incorporating into the building or changes to the way in which buildings are rated.