New dwellings for which planning permission was applied for from late 2019 onwards must meet Nearly Zero Energy Building (NZEB) standards, which in practice means achieving a BER of around A2 with a strong renewable energy contribution. The exact requirement depends on the Technical Guidance Document Part L in force when the building application was made, so the specific standard should be confirmed with the assigned certifier or building control authority.
Since the transposition of the EU Energy Performance of Buildings Directive into Irish building regulations, new dwellings must be built to Nearly Zero Energy Building (NZEB) standard. This is implemented through Technical Guidance Document L (Conservation of Fuel and Energy — Dwellings), which sets maximum energy and carbon performance coefficients and requires a meaningful proportion of the home's energy demand to come from renewable sources, typically a heat pump, solar thermal or photovoltaic panels. In practice, compliant new houses generally achieve a BER in the A rating band, most commonly A2 or better, though the regulations set performance coefficients rather than a BER letter directly.
The precise version of Part L that applies depends on when the planning application, or in some cases the building control commencement notice, was lodged, because updated editions of the technical guidance document have been introduced over time with tightening requirements. Builders and designers work from the version in force at the relevant date, and the assigned certifier or building control authority can confirm which standard applies to a specific project.
Compliance is demonstrated through the same software-based calculation used to generate a BER, called DEAP (Dwelling Energy Assessment Procedure), carried out by a qualified assessor at design stage and again after completion to produce the final BER certificate lodged with the completion certificate.