Energy Performance Certificate reform consultation

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Closes 16 Oct 2023

Consultation Questions: Domestic Energy Performance Certificate Metric Reform Proposals

Domestic Energy Performance Certificate (EPC) metrics are widely used to provide information on a home, and yet, the current metrics do not accurately reflect the fabric efficiency of a home nor do they support our transition to net zero. To address this, we are proposing to reform the current metrics to provide more holistic information about the efficiency of a home that is relevant to owners and occupiers. We propose the following set of headline metrics:

  • Fabric Rating
  • Cost Rating
  • Heating System Type

These three metrics each support distinct policy purposes – the heat demand, the cost to run the dwelling, and whether the heating system is zero direct emissions compliant.

In addition, we propose to display:

  • the Emissions Rating; and,
  • the Energy Use Indicator.

These are not intended to be used as headline metrics but provide information that can be useful to stakeholders.

Additional metrics set out in the draft Energy Performance of Buildings Directive may be required in a separate section to enable alignment with EU countries. If this is the case, these will also be added to the EPC as secondary metrics.

Beyond metrics, we also propose to ensure the EPC provides a clear description of the energy efficiency features of the dwelling, showing them in a list. This could include the insulation condition of the walls, as identified in accordance with the relevant assessment methodology. We intend to review the presentation of this information in the current EPC format, and consider whether this can be made more prominent.

Question 1. Do you agree with the set of metrics that we propose to display on the reformed Energy Performance Certificate?

Summary of Proposed Domestic EPC Metrics

This first table summarises our proposed set of domestic Energy Performance Certificate (EPC) metrics and shows the headline metrics which would be widely used in policy.

Proposed Metric

Description

Display

Fabric Rating

Efficiency of the building fabric

A-G scale and kWh/m2/yr

Energy Cost Rating

Running cost per year

A-G scale with 1-100 rating

Heating System Type

Type of heating system

Heating system classification (zero direct emissions or not)

This second table presents the secondary metrics that we propose to also display on EPCs. These metrics provide useful information to stakeholders and users however are not directly used by policy. We intend to clearly separate these metrics from those above, to provide clarity to users.

Proposed Metric

Description

Display

Emissions Rating

Rating based on the CO2e emissions per square meter

A-G scale with 1-100 rating

Total Energy Use

The total amount of energy used per year

kWh/m2/yr

kWh/m2/yr - Kilowatt hour per square metre annually

CO2e - Carbon Dioxide equivalent

Question 2. Are there additional metrics that you think should be included on the EPC, or metrics that you do not think should be included?
Question 3. Considering our proposal to include a Fabric Rating on EPCs, do you think this metric should include domestic hot water heat demand?

Fabric rating

The metrics currently shown on EPCs do not solely reflect the energy efficiency of the building fabric, and so do not drive the fabric energy efficiency improvements that are key to improving our housing stock. By ‘fabric efficiency’ we mean how well the building retains heat. This includes how well insulated the walls, roof, and floor are.

To address this, we propose to add a metric to reflect the fabric of the home, namely the fabric rating. This is primarily intended to support any future fabric energy efficiency standards. This would provide a clear rating of the dwelling’s fabric efficiency. We have developed two potential options for this metric with BRE:

  1. The energy required to be supplied by the heating system to achieve standardised conditions, including heating, cooling, and domestic hot water heat demand.
  2. The energy required to be supplied by the heating system to achieve standardised conditions, including heating and cooling demand but excluding domestic hot water heat demand.

Domestic hot water means the heat required to be provided to the dwelling’s hot water system to meet needs based on standardised assumptions.

Question 4. Do you have a view on the way that the Fabric Rating mapped against a scale, for example, how ‘A’ or ‘G’ rated performance is determined?

Proposed Approach to Scaling Fabric Metric

We are interested in views on approaches to designing the scaling of the proposed Fabric Rating to assign bands from A - G (i.e. the A – G distribution against kWh/m2/yr values). The approach to scaling the bands is important because it will determine which band dwellings fall into, and the way in which dwellings can move bands.

We have considered linking the cut-off for band C in the Fabric Rating to the cut-off for band C in the Energy Efficiency Rating (EER). This would ensure a degree of consistency between the current EER and the proposed Fabric Rating. As demonstrated in the BRE report, there is not a one-to-one relationship between Fabric Rating and EER, much of which is due to the difference in fuel cost between gas and electricity. We have investigated other ‘anchors’ such as basing band A on PassivHaus equivalent performance, and band B on typical new build fabric performance.

Alternatively, the Fabric Rating bands could be set independently of EER band C. based on another approach. This would allow greater freedom to set appropriate bands against the distribution of fabric values, at the cost of not having a clear link between Fabric Rating and EER band C.

The full BRE report contains more details on the options above.

Question 5. Do you agree with our proposal to give more prominence to the energy efficiency features of the home (such as the depth of loft insulation)?

Numerical Metrics

Numerical metrics are useful because they quantify the performance of the dwelling. However, they may be less suited to providing clear and actionable information to homeowners, and policymakers. For example, it may not be obvious to homeowners how to reach a specific numerical heat demand value, or they may make improvements but miss a threshold cut-off. On the other hand, displaying whether or not the walls or loft, for example, are insulated (a difficult to define term in itself) is unambiguous. There are many situations where an EPC assessor may not be able to accurately determine this status and so assumptions are made based on the approximate date of construction. For this reason, we propose to make details about the insulation level of the dwelling more prominent on the EPC. Details are already displayed in the “Summary of the energy performance related features of this home” section on the EPC. We will consider whether the presentation of this information is sufficiently clear for users.