What is the NZEB regulation (Nearly Zero Energy Buildings)?

By Vincent Brady

There seems to be some confusion around how the introduction of NZEB buildings is going to affect the associated trades, particularly in the construction industry. Below, we’ll discuss what the changes are, why they were brought in, and what it means from different viewpoints.

If you’re in an associated trade, are considering having a new property (Commercial or Residential) built, or are a developer, you need to understand these regulations. As the introduction to Ireland’s National Plane says, ‘Energy use and CO2 emissions associated with the built environment continue to be significant and measures to reduce their impact in both new and existing buildings will continue to be an important component of Government energy and climate change policies.

Definition of NZEB and where it comes from

The NZEB regulation has been brought in by the European Commission. It requires each member state to submit national plans that describe how they intend to increase the number of NZEBs in their respective countries. There are large differences in the history of building regulations across member states, so the steps taken by some countries will need to be more dramatic than others.

The European Commission define an NZEB as a building with very high energy performance. They also state that the low amount of energy required by these buildings should mostly come from renewable sources.

The European Commission has been promoting NZEBs for years and published guidelines in 2016 to help promote the adoption of the required standards. They have set a deadline for all new buildings to be compliant by 2020. The same regulations will also apply to renovations that affect more than 25% of the surface area of an existing dwelling. If you’re unsure of anything to do with NZEB you should seek professional guidance.

What do you have to do to an existing non-residential building you’re renovating?

If you are renovating an existing building and are going to be carrying out works on ‘more than 25% of the surface area of the building envelope’, then there will be certain tasks that have to be performed as part of the renovation. These include:

Upgrading a heating system that’s more than 15 years old.

Upgrading a cooling system that’s more than 15 years old.

Upgrading lighting that’s more than 15 years old.

Further details can be found on the Housing website document, Conservation of Fuel and Energy – Buildings other than Dwellings.

What if you’re building a new commercial property?

All new non-residential builds are required to be 60% more efficient than they were in 2008. This is achieved through a combination of services, lighting and materials used, as well as a mandatory requirement for renewable sources. While the building is required to be very energy efficient, at least 20% of the energy used must come from renewable sources. However, there is some flexibility built in if the building exceeds the energy requirements of the regulations.

What do the new regulations mean for residential new builds?

All new buildings must be compliant with certain criteria, such as a Maximum Energy Performance Coefficient of 0.3, a Maximum Carbon Performance of 0.35 and a renewable energy ratio of 20%. This gives an equivalent improvement of 25% over the building regulation of 2011. You can see examples on the DEAP Software from the Domestic BER Resources page of the Sustainable Energy Authority of Ireland.

Do the regulations also apply to domestic renovations?

Yes. The same gauge is applied to renovations as commercial properties. If a renovation affects an area greater than 25% of the total surface area of the existing dwelling. This can include extensions, material alterations, material changes of use, major renovation and the replacement of external doors, windows and roof lights. The aim of the renovation regulation is to limit the energy requirements for the operation of the dwelling, thereby reducing CO2 emissions. Key areas to be addressed include:

  • Fabric insulation: providing reasonable levels of fabric insulation in all new construction, including the limitation of thermal bridging including, where provided, replacement windows and doors. Guidance is given in sub-sections 2.1.2 and 2.1.3;
  • Air tightness: limiting air infiltration through the newly constructed elements as far as is practicable. Guidance is given in sub-section 2.1.4;
  • Heat Generator: providing an efficient heat generator as set out in sub-section 2.2.2:
  • Building Services Controls: where new space and/or water heating services are provided, controlling, as appropriate, the demand for, and output of these space heating and hot water services. Guidance on appropriate measures is given in sub-section 2.2.3; and
  • Insulation of pipes, ducts and vessels: limiting the heat loss from pipes, ducts and vessels used for the transport or storage of heated water or air, as set out in sub-section 2.2.4.
  • When a dwelling undergoes major renovation, the energy performance of the whole dwelling should be improved to cost optimal level in so far as this is technically, functionally and economically feasible.

More detailed guidance on all aspects of the new regulation in relation to domestic dwellings can be found on the Department of Housing website.

Cost Optimal Study

The Cost Optimal Study was carried out to define the energy performance requirements for new buildings and major renovations. It takes into account the capital, operational, maintenance and carbon costs of various energy efficient solutions and renewable technologies. There is a residential and a non-domestic version of the study.

Ask the experts to ensure your project is fully compliant

Many people planning to undertake a new project, whether a new build or renovation, will be worried about the cost implications of this new regulation. However, being compliant and achieving your goals doesn’t have to mean your budget now has to be much bigger. You can still achieve all your goals with a sensible budget and a cost-effective plan, and we can help you do it.

With nearly two decades experience in a wide variety of areas, including structural engineering, planning permission, fire, energy, and even forensic investigation, our team at Banrach Consulting Engineers are ideally placed to help you.