BER Methodology

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 can be found at 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. Under the DEAP methodology, a new dwelling which meets the minimum standards as set out in the Building Regulations is likely to score the following ratings: Apartment: B3 House: C1

In order to achieve higher ratings developers will be required to design dwellings which go above the minimum standards and which include energy efficient features such as condensing boilers, passive solar design, energy efficient glazing, increased insulation levels, renewable energy technologies, etc.