What is nZEB and what does it mean for me?

16th November 2017

Our technical team have recently received enquiries about nZEB, with uncertainty about what it means for Irish construction. So our Specification and Product Development Manager, Jason Martin, outlines what nZEB is and what it means for those who are challenged with meeting the new standards in our latest video.

nZEB Origins

nZEB stands for Nearly Zero Energy Buildings, and it was introduced into the 2010 revised version of the EPBD (Energy Performance of Buildings Directive). This document loosely describes nZEB as a building with a very good energy performance, with a significant proportion of that energy achieved from on-site, or closely sourced renewable energies.

Key Dates for nZEB

All public buildings built after 31st December 2018 need to be built to nZEB standard, and all buildings built after 31st December 2020 must meet this standard. So, given the date for the compliance of public buildings, it is clear that any public building now at planning or design stage should achieve nZEB standards. And with all buildings soon to be nZEB standard, consideration should be given at this stage for all other building designs.

The Path to nZEB

So, where does the nZEB standard fit in relation to current and previous regulations? All regulations since 2005 have been based on a reference dwelling from 2005 regulations. The Energy Performance Co-efficient (EPC) of this 2005 reference dwelling was 1. The regulations then changed in 2008, and the EPC was changed to 0.6, representing a 40% improvement on the 2005 standard. Current regulations were introduced in 2011, and the EPC was improved by a further 20% standard to 0.4. So there has already been a full 60% improvement on the 2005 EPC standard.

Now, nZEB is approaching, and the Energy Performance Co-Efficient will improve by a further 10% to 0.3, which will see a full 70% improvement on the 2005 reference dwelling.

Key Figures for nZEB

When nZEB comes into force, it will mean all houses will need to achieve A2 BER rating, compared to today’s typical A3 standard.

The Primary Energy Consumption must be less than 45kwh/m2/annum.

The Maximum Permitted Energy Performance Co-Efficient (MPEPC) will be 0.3, and the Maximum Permitted Carbon Performance Co-efficient (MPCPC) will be 0.35.

An important point to note is that back stop U-Values will remain the same, so it will still be possible to meet the nZEB standard with the current back stop U-Values, although this may be difficult to achieve.

nZEB: The Simple Solution

So, what is the best and most cost-effective way to achieve this additional 10% improvement on the Energy Performance Co-Efficient? The EPBD has said that an nZEB building must have a very high energy value, and that a significant proportion of that energy must be achieved from alternative or renewable energies. It also goes on to say that the building’s heating and cooling demands must be designed to an optimal level before looking at these renewable or alternative energies. In other words, design a building which needs little energy, then we don’t have to worry a lot about where that energy comes from. This is promoting the fabric first approach, which is the most cost-effective solution to achieving the nZEB standard.

When adopting the fabric first approach, we need to address the building’s thermal bridges, and use project specific Psi values as opposed to default thermal bridging factors in our BER calculations.

Quinn Lite have a full suite of Accredited Construction Details and associated Psi Values, which are up to 750% better than those in the current Acceptable Construction Details. So it’s details such as these that are going to be key to achieving nZEB in a cost optimal way.

We also have a new wall construction, SIMS by Quinn. SIMS is a Super Insulated Masonry Solution, which combines the benefits of Quinn Lite thermal blocks, thin joint technology, and a certified external insulation system. The solution is ideal for achieving nZEB standards in a cost-effective way, and also provides a rapid build solution to meet the demand for speed of construction.

For further information on SIMS by Quinn, or other ways we can help you achieve nZEB using a fabric first approach, contact our Technical Team on technical@quinn-buildingproducts.com or call +44 28 67748866.