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Heat Loss Indicator (HLI) for Heat Pumps in Ireland: Is the 2.3 Limit Still a Barrier?

SEAI's July 2026 FAQs explain when the 2.3 W/(K·m²) Heat Loss Indicator still applies to heat pump grants and where it no longer blocks One Stop Shop projects.

SM Samuel Mario Pop AchimFounder & editor Updated 3 min read

For years, one number has decided whether a heat pump project in Ireland could go ahead: the Heat Loss Indicator. In July 2026, SEAI published FAQs explaining that, for some schemes, it no longer blocks the grant. Here is what changed and what did not.

What the HLI measures

SEAI’s FAQ expresses the Heat Loss Indicator in W/(K·m²), in other words, watts of heat lost per degree of temperature difference, per square metre. The lower the number, the less heat the home loses. For heat pump grants, a threshold of 2.3 has been the general benchmark.

The document is a programme FAQ, so it does not explain how the indicator is calculated or who measures it. For the method, ask your One Stop Shop or contractor.

Indoor heating equipment, insulated pipes and a hot-water cylinder.

What has changed

SEAI states that the 2.3 threshold no longer applies to heat pumps installed under:

  • the One Stop Shop scheme
  • the Community Energy Grant programme
  • the Warmer Homes Scheme, but only when the Warmer Homes team advises it

The stated aims are to increase heat pump uptake, support traditional and hard-to-treat homes, focus on delivery quality rather than a single metric, and improve affordability.

What has not changed

The Better Energy Homes scheme, where you apply for individual grants, is unchanged: SEAI says the HLI must still be achieved prior to grant payment. SEAI also says registered One Stop Shop, Community Energy Grant or Warmer Homes contractors cannot currently apply the flexibility to Better Energy Homes installations, though SEAI is reviewing this.

For the Energy Efficiency Obligation Scheme, the 2.3 threshold applies to deemed scores, and to homes notified towards residential or energy poverty targets that do not reach at least a BER B.

Who carries the responsibility

Under the One Stop Shop, Community Energy Grant and Warmer Homes Scheme, SEAI says service providers take responsibility for the whole heat pump design, including the heat loss assessment, through a design-led approach. All works must follow the SEAI Domestic Technical Standards and Specification.

Where a homeowner under the One Stop Shop or Community Energy Grant receives a Home Energy Assessment and the HLI is above 2.3, an SEAI Technical Advisor must complete the heat pump technical assessment form. That form is not required if the homeowner does not take the Home Energy Assessment grant.

What it means for you

If you were told your home was “not heat pump ready” because of the HLI, it is worth asking again, because the answer may now depend on which route you use. If you use the One Stop Shop, the limit no longer blocks you. If you go through Better Energy Homes individually, it still does.

Remember that grant eligibility is not the same as running cost. Read our heat pump grant guide for the grant amounts and our running cost verdict for whether a heat pump will pay off in your house. Our One Stop Shop comparison explains the routes.

Frequently asked questions

01What is the HLI limit for a heat pump grant?
SEAI's FAQ says heat pumps must meet an HLI of 2.3 W/(K·m²) or less under most schemes. The same document sets out where that threshold has been relaxed.
02Does the 2.3 limit still apply to the One Stop Shop?
According to SEAI's July 2026 FAQ, the threshold no longer applies to heat pumps installed under the One Stop Shop, the Community Energy Grant programme, or the Warmer Homes Scheme (for the Warmer Homes Scheme, only when its team advises it).
03What about the individual Better Energy Homes grants?
There is no change. SEAI says the HLI must still be achieved before grant payment on Better Energy Homes.
04If my home is above 2.3, does the contractor take on the risk?
SEAI says service providers on the One Stop Shop, Community Energy Grant and Warmer Homes Scheme take responsibility for the whole heat pump design under a design-led approach, including the heat loss assessment.
05Do I still need insulation if the limit is relaxed?
The FAQ is about grant eligibility, not about comfort or running costs. A poorly insulated home can still cost more to heat with any system, so ask your provider for a design that explains the expected performance.

Sources

  1. 1 SEAI — Programme Specific Heat Loss Indicator Flexibility FAQs (July 2026) seai.ie

Grant amounts and prices change. We check figures against official sources, but always confirm current details with SEAI before making a decision.

Put the guide into practice

Run your own numbers before you decide.

Examples are estimates, not surveyed prices or guaranteed savings.

How we use sources and correct errors

SM

Written & reviewed by

Samuel Mario Pop Achim

Founder & editor

Samuel Mario Pop Achim is the founder and editor of Irish Home Energy. He researches home energy choices for households in Ireland. His guides distinguish official scheme conditions from illustrative calculations and are not a substitute for a qualified assessment.

Last reviewed & updated 23 October 2026. Our methods

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