The Directive defines a Zero Emission Building (ZEB) as a building with very high energy performance, in accordance with Annex I. Such buildings require zero or very low energy, produce no on-site carbon emissions from fossil fuels, and generate zero or very low operational greenhouse gas emissions.
In Ireland, a Zero Emission Building (ZEB) will attain an A0 BER rating. To achieve this rating, a dwelling must meet all the following criteria:
- Primary energy value: ≤ 42 kWh/m²/year
- Carbon emissions value: ≤ 5 kg CO₂eq/m²/year
- No on-site use of fossil fuels
- Capability to respond to external signals
- Energy demand met by carbon-free sources or compliant with national requirements
- Compliance with nZEB standards
If a dwelling does not meet all ZEB criteria but has a primary energy value of ≤ 75 kWh/m²/year, it will be assigned an A rating.
The DEAP software automatically assesses criteria 1, 2, 5, and 6. Additional clarifications are provided below.
Notes
- Primary Energy Value: This is the primary energy value calculated by DEAP.
- Carbon Emissions: This is the CO₂eq figure generated within DEAP.
- No On-Site Fossil Fuel Use: DEAP evaluates this criterion based on the fuel types entered. However, the Assessor may override this assessment if a third heat source exists in the dwelling but is not included as the primary or secondary heating system in the calculation.
- Capability to Respond to External Signals:
The concept of the capacity to react to external signal should be understood in relation EPBD Recast 2024 where a buildings capacity to react to external signals can contribute to demand-side flexibility of the electricity grid.
Capacity to react to external signals and adjust the energy consumption can be defined as a system with the capacity to communicate with the electricity grid and, whenever they receive the appropriate signal from the grid, to contribute to system flexibility by reducing their energy demand to the extent possible, by storing more energy when there is more and/or cheaper energy available, or by exporting more or less renewable energy generated on-site.
Due to the current limitations of the electricity grid, DEAP only considers whether a system is present in the dwelling with this capacity, not whether the system is functioning in this manner.
This is a manual Assessor entry.
- If a dwelling has a heat pump system or a photovoltaic (PV) installation, it is capable of responding to external signals and adjusting energy consumption. This reflects potential capability only and does not indicate that such functionality is currently active.
- If a dwelling does not have a heat pump system or a photovoltaic (PV) installation, assume the dwelling is not capable of responding to external signals and adjusting energy consumption accordingly.
- Energy Demand Criteria: Two checks are performed:
- Is the building’s energy demand is fully met by renewable sources; or
- Is the carbon-based portion of grid electricity complies with national criteria set by Government. Only one of these need to be met.
- nZEB Compliance: This is based on the EPC, CPC, and RER checks within DEAP, which collectively demonstrate compliance with nZEB requirements.
The ZEB tab in the DEAP workbook contains the formulas used to carry out these checks. Assessors are advised to review the workbook in their own time.
Guidance on re-use of data for ZEB can be found here