Nearly Zero Energy Building standard

What is the NZEB standard?

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.

Nearly Zero – Energy Buildings’ means a building that has a very high energy performance, Annex 1 of the Directive and in which “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“.

On 29th July 2016 the European commission published additional guidance on the NZEB standard. Specifically for the Oceanic zone which applies to Ireland the guidance proposes the following recommendation.


Offices: 40-55 kWh/(m2.y) of net primary energy with, typically, 85-100 kWh/(m2.y) of primary energy use covered by 45 kWh/(m2.y) of on-site renewable sources;

New single family house: 15-30 kWh/(m2.y) of net primary energy with, typically, 50-65 kWh/(m2.y) of primary energy use covered by 35 kWh/(m2.y) of on-site renewable sources; and

In order to move towards the NZEB standards from the current regulations, Government is expected to issue a revised Building Regulations Part L – Conservation of Fuel and Energy (and the accompanying Technical Guidance) this year. This is likely to be defined as using 40% to 60% less energy than under current regulations. This is unlikely to meet the recommendation outlined above so a further revision is likely required ahead of 2020.

In January 2017, the Department of Housing Planning, Community and Local Government, the Office of Public Works, the Department of Education and Skills, the Health Services Executive and Sustainable Energy Authority of Ireland published an Interim NZEB Specification for Public Sector buildings. This sets out a performance specification for new buildings owned and occupied by Public Authorities after 31st Dec 2018. It is intended that this specification will form the Nearly Zero Energy Buildings requirement in the interim period until the new 2017 Part L for Buildings other than Dwellings takes effect.

Who should know about it?


Financial Institutions and Investors

Property Advisors

Construction Professionals


What will implementation look like in Ireland?

Commercial and Non residential - In order to move towards the NZEB standard from the current regulations, Government is expected to issue a revised Building Regulations Part L – Conservation of Fuel and Energy (and the accompanying Technical Guidance) this year. This is likely to be defined as using 40% to 60% less energy than under current regulations.

An Interim NZEB Specification for Public Sector buildings has already been published and is available here.

Residential  - There has already been considerable progress towards the NZEB standard in Ireland with revisions in 2008 and 2011 to Building Regulations Part L -residential. One further step of a 10 -30 % improvement is required to bring building regulations in line with the NZEB requirement.

How is the improvement measured – Commercial /non residential?

NEAP (Non domestic Energy Assessment Procedure) uses the software iSBEM to measure compliance with Part L Technical Guidance Document, Conservation of Fuel and Energy – Buildings other than dwellings in 2014. This can be used to calculate improvements over current building regulations for smaller buildings. Suitable software is been developed for the Irish market to more accurately demonstrate compliance for larger, more complex buildings.

Non-domestic  building  energy  calculation  software  packages  to  calculate  building asset  and  operational ratings  must  now  be  approved  by  the Sustainable  Energy Authority of  Ireland  (SEAI)  before  they  could  be  available  for commercial  use  in  the  Republic  of  Ireland.  For  more  information  on  the  validation  procedure  and  the approval scheme is available on a SEAI website:

What does this mean for commercial and non residential building design?

A combination of some of the following likely needed to achieve a 60% improvement.

  • Building insulation levels will be greatly improved
  • Glazing ratios may need to be considered
  • Insulation value of the glazing itself  will be considerably improved
  • Airtightness standards will be introduced including mandatory airtightness test on every building
  • Enhanced calculation of linear thermal bridging probably required particularly for the 60% improvement
  • The use of  renewables and free cooling will  be required
  • The use of solar shading will need to be considered
  • Renewables will need to cover a substantial part of energy use
  • Much more efficient lighting and services will be needed

What Skills are needed for the NZEB standard?

There may be  a steep learning curve to achieve the improved standards  if professionals have not already upskilled. Demonstrating compliance will become more technical. Design teams need to develop understanding of the software to demonstrate compliance, though more guidance from Government is still required. Achieving higher level improvements will require greater integrated design team working at an earlier design stage. The emphasis on the  fabric of the building, will need more in-depth  understanding of designing for solar shading, thermal bridge free construction, air tightness and glazing ratios etc. Greater knowledge is required around more efficient lighting, services and renewables.

Where can I get these NZEB skills?

FREE Postgraduate Course @ DIT in Design of Buildings to NZEB

The Dublin School of Architecture, DIT Bolton Street, is seeking applications from building professionals to join a free postgraduate course in the design of buildings to meet the Nearly Zero Energy Building (NZEB) performance standard. The initial delivery of the 10-credit postgraduate module, entitled ‘Professional Energy Skills in NZEB’, is being supported by EU funding, with the first cohort commencing in January 2016. Find out more.

Other courses and seminars – Professionals

NZEB Open Doors – supported by SEAI, the event will enable the public to visit really good examples of Nearly Zero Energy Buildings (NZEB) in order to inspire them to aim for similar standards for their own building or renovation projects find out more

Sustainco – the project aims to increase the visibility and understanding of the Near Zero Energy Building (NZEB) philosophy, with special emphasis on rural areas find out more.

Nearly Zero-Energy Building Strategy 2020 (ZEBRA2020).
ZEBRA2020 aims at creating an observatory for nZEBs based on market studies and various data.

The challenges to implement Nearly Zero-Energy Buildings (NZEB) and achieving minimum shares of Renewable Energy are tremendous. There are various indications raising concerns regarding the reliability of Energy Performance Certificate (EPC) declarations and the quality of the works. Achieving a significant improvement requires strong commitment from authorities and other major players, as well as sufficiently broad societal support.

Construction workers – Qualibuild

The QualiBuild  project is funded by the Intelligent Energy Europe Programme and started in November 2013. This has trained over 200 construction workers in the pilot phase and national roll out from ETBs, Institutes of Technology and private trainers  starts in Autumn 2016.   Many construction workers lack the core knowledge in relation to low energy buildings. This addresses one of the main issues identified within the Irish Build Up Skills (BUSI) RoadmapFind out more.

The Construction Workers Skills Register is a register of construction and craft workers who have undertaken up skilling in low energy construction for NZEB and have completed the Foundation Energy Skills course developed by the QualiBuild project..

Key Studies

News on NZEB – Europe

Ask the Experts: Is there a unique definition in Europe for a Nearly Zero Energy Building?

In our Ask The Experts section, BUILD UP provides expert answers to common questions related to energy efficiency in buildings. This month we ask whether a single European definition for Nearly Zero-Energy Building (NZEB) exists. Read more

Plus-energy school retrofit in Germany

Two school buildings in Reutershagen, Germany – one of them from the early 1960s – were refurbished according to energy-plus standards. An ORC power plant with district heating and integrated photovoltaics deliver energy for heating, water and lighting. Read more

Nearly Zero Energy Hotels  (neZEH)

neZEH encourages and proposes concrete solutions to EU hotel owners willing to become a nearly Zero Energy Hotel. Providing technical advice for nZEB renovations,demonstrating the sustainability of such projects and promoting front runners, neZEH has the ambitious goal of sensitizing 15,000 hotels across Europe, engaging them in the EU nearly zero energy building (nZEB) strategy. Read more

Related Posts

The Irish Green Building Council has launched a short guide on NZEB to help developers, property advisors and other construction professionals keep up-to-speed with the new standard. The one page document can be downloaded here 

Nearly Zero Energy Building is Nearly here! Are you ready?

Data tool – nZEB buildings

The tool on nZEB buildings enables to display relevant indicators for a sample of nZEB buildings and high efficient buildings estimated to be at nZEB level, built recently in selected European countries. It aims at providing information of best cases in Europe, thereby showing most recurrent technologies, materials and strategies towards the nZEB target. The tool differentiates residential and non-residential nZEB buildings and shows some of the most significant indicators regarding energy performance, passive and active solutions and production of renewable energy. Access