Heat and Energy Efficiency Technical Suitability Assessment: consultation analysis

Q10 Relationship between the EPC and HEETSA

Most respondents agreed that HEETSA outputs should feed into the EPC in some way. Among those supportive of this, 28 (37%) favoured Option 1 whereby HEETSA should result in the production of a revised EPC. 29 (38%) preferred Option 2 whereby HEETSA outputs should be considered acceptable evidence to override EPC default values.

In contrast, nine respondents (12%) felt that HEETSA should not influence the EPC or its ratings. A further ten respondents selected ‘other’; these responses were split between being positive towards allowing HEETSA outputs to feed into EPCs and expressing concerns towards modifying EPC inputs and potentially losing the consistency needed for a comparative tool.

Individual respondents were generally sceptical about a HEETSA resulting in the automatic production of a revised EPC, with only two out of 18 supporting Option 1. Their views were split between Option 2 (n=7) and opposing any influence on the EPC and its ratings (n=5).

Organisations, on the other hand, were positive towards a HEETSA resulting in the automatic production of an EPC. Of the 70 responses from organisations, 26 supported Option 1. 22 supported Option 2, while only four stated a HEETSA should have no influence on EPC outputs. This division between Option 1 and Option 2 was observed consistently across all types of organisations.

Reasons for HEETSA outputs to feed into EPCs

Respondents who supported integrating HEETSA outputs into EPCs cited several benefits. These are relevant to both Options 1 and 2. The more frequent responses are presented first.

• The most frequently cited reason was to improve the accuracy of EPCs. Of these, a few respondents specifically highlighted the value of reflecting HEETSA’s improved assessment with regards to complex buildings (such as heritage properties and tenements) within EPC outputs.
• It would reduce duplication of effort.
• It would facilitate retrofit planning and access to funding mechanisms.
• It would help establish systems that enable data integration and transparency such as building passports.

The most common reason given in favour of Option 1 over Option 2 was to avoid the risk of contradictory information being presented simultaneously. This could cause confusion for users of both HEETSA and EPCs.

Support for Option 2 over Option 1 was based on the view that EPCs and HEETSA serve distinct purposes, and a clear separation should be maintained.

• EPCs are a comparative tool, where consistency of inputs and assessments is essential for benchmarking across buildings. In contrast, HEETSA is intended as a bespoke assessment to inform the design of improvement measures.
• Important for domestic energy assessor oversight in determining which EPC inputs can be overridden. This is to avoid scenarios where buildings using default values might appear to perform better than those using accurate, measured data.
• HEETSA recommendations should not be concerned with EPC results, as the EPC algorithm may not fully capture the real-world benefits of certain measures.

Some respondents supported a hybrid approach. They suggested that HEETSA should have the option to produce a valid EPC as part of its outputs.

Concerns and reasons for HEETSA outputs to not influence the EPC

Concerns regarding allowing HEETSA outputs influencing EPCs included the following.

• Introducing varying levels of accuracy could undermine the EPC’s role as a consistent, standardised comparative tool.
• Linking HEETSA to EPCs might incentivise HEETSA assessors to prioritise measures that improve EPC ratings, rather than those best suited to the building.
• There would be cost and qualification implications if HEETSA assessors were also required to produce valid EPCs.

Other views on linking HEETSA and EPCs

Regardless of their preferred option, a few respondents supported downplaying EPC recommendations in favour of HEETSA-driven advice.

Additional comments from Workshops

The workshops identified the following additional point.

• Auditing considerations: If HEETSA is to produce EPCs, it will need to be subject to the same auditing process as the EPCs.