Nearly Zero Energy Building

What is the Nearly Zero Energy Building Standard?

NZEB Definition

“NZEB means a building that has a very high energy performance where 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”

Near Zero Energy Buildings – NZEB Ireland


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

On the 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:

By 2020 all new dwellings in Ireland will have an Energy Performance Coefficient (EPC) and Carbon Performance Coefficient (CPC) of 0.302 and 0.305. This takes account of the energy load for space heating, water heating, fixed lighting and ventilation. For a typical dwelling this will equate to 45 kWh/m2/annum with a very significant proportion of which will be covered from renewable energy sources produced on-site or nearby. In terms of BER certificates, all new dwellings should be rated as A3 or higher.

Typical performance standards for NZEB for dwellings

Low Energy Dwelling with Solar Thermal Domestic Water Heating
Primary Energy
(Kg/m2yr) 10
EPC 0.302
CPC 0.305

NZEB Buildings other than Dwellings:


By 2020 it is proposed that all new buildings other than dwellings in Ireland will achieve a 50% to 60% aggregate improvement in terms of energy efficiency and reduction in CO2 emissions. The energy metrics to be considered will includes the energy load for space heating, water heating, cooling, fixed lighting and ventilation.

Target Year Improvement on TGD L 2008 Buildings other than Dwellings performance level
Intermediate 2014 40%+
Final 2020 – 60%
Note: Targets will be further refined when developing new technical performance standard Technical Guidance Document L – Buildings other than Dwellings

The Thermohouse Solution for NZEB Buildings

The Thermohouse NZEB solution is an integrated building envelopewalls, floors and roof. Our system delivers:

1. Superior air tightness equivalent to passive standards without the need for additional airtightness products
2. High levels of insulation with varying U-values from 0.195 to 0.10 W/m2K
3. Minimal thermal bridging
5. Sustainable and environmentally friendly

Overall, Thermohouse buildings can meet the NZEB requirement of 45 kWh/m2/annum,
Exceed NZEB requirements achieving <25 kWh/m2/annum, depending on your requirements.