‘Nearly Zero Energy Buildings’ means a building that has a very high energy performance. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby.

Nearly Zero Energy Building (NZEB)

The NZEB standard will apply to all new buildings occupied after the 31st December 2020. For Public Sector bodies, the standard will apply to all new buildings owned or occupied by the 31st December 2018.

As with previous Building Regulations there are transitional arrangements in place where buildings are occupied after these dates but work commenced prior to 31st December 2018. An Interim NZEB Specification for Public Sector buildings has already been published and is available here.

What are Nearly Zero Energy Buildings

The definition for Nearly Zero Energy Buildings in the Energy performance in Buildings Directive (EPBD) is "a very high energy performance, as determined in accordance with Annex 1, The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby".

Ireland carried out a cost optimal analysis in 2013 to define NZEB requirements. Part L of the Building Regulations defines the requirements in legislation.

Requirements for Non Domestic Buildings

For new buildings
For all new builds, an equivalent to a 60% improvement in energy performance on the 2008 Building Regulations is required. This means an improved energy performance for the fabric, services and lighting specification. It also introduces a mandatory requirement for renewable sources. The renewable sources must in general provide 20% of the primary energy use, however there is flexibility where the building is more energy efficient than the regulations. This typically corresponds to an A3 Building Energy Rating.


For major renovation
For existing buildings under EPBD, major renovation is where “more than 25% of the surface area of the building envelope undergoes renovation”. This will require that the building is brought up to cost optimal level, which is defined in the building regulations as:

  • Upgrade Heating System more than 15 years’ old
  • Upgrade Cooling and Ventilation Systems more than 15 years’ old
  • Upgrade Lighting more than 15 years old.

Further details can be found on the Department of Housing, Planning and Local Government website.
 

Requirements for Domestic Buildings

This is currently out for public consultation, refer to Department of Housing, Planning and Local Government website for proposed changes to the regulations and DEAP methodology.

For new buildings

For all new builds, its proposed that NZEB will be equivalent to a 25% improvement in energy performance on the 2011 Building Regulations. A range of examples are shown in excel versions of the DEAP software available in the public consultation.

For major renovation

For existing buildings, it is proposed that major renovation is typically activated where external wall is renovated. The cost optimal level is a primary energy performance of 125 kWh/m2/yr when calculated using DEAP or upgrade of roof insulation and heating system.

Energy Show Workshop on NZEB

NZEB Domestic Session

Energy Show presentations

This year at the Energy Show we hosted an NZEB workshop with support from DHPLG, RIAI and CIBSE. The event presented details of the public consultation for Part L for Dwellings of the Building Regulations which is open until 8th June 2018. Please find below a link to each presentation,

NZEB for Dwellings

NZEB for Non Domestic Buildings

 

FAQs

The European Energy Performance of Buildings Directive Recast  (EPBD) requires all new buildings to be Nearly Zero Energy Buildings (NZEB) by 31st December 2020 and all buildings acquired by public bodies by 31st December 2018.

For non-domestic buildings, compliance will be demonstrated using the NEAP methodology. This is currently being developed and will be published in Q2 2018. An interim methodology is available for use now.

For domestic buildings, compliance will be demonstrated using the DEAP methodology. DEAP is currently being updated to account for NZEB.