Addendum to NISEP 2023/25 Framework Document published

The Addendum to the NISEP 2023/25 Framework Document was published in February 2024, setting out changes to the Northern Ireland Sustainable Energy Programme for the remainder of the two-year framework. The programme is funded through a Public Service Obligation collected from all electricity customers, and 80% of its funding is ring-fenced for vulnerable customers¹.

The main changes set out in the Addendum were updated income eligibility criteria, intended to target support more closely on household need, and in-year adjustments to cavity wall insulation extraction and refill caps. For Priority Whole House Solution schemes the 30% cap was removed, while for Priority Individual Measures schemes the cap rose from 30% to 50% of all cavity wall insulation jobs¹. Extraction and refill work is permitted only where existing insulation is defective and the property is more than 20 years old¹.

Heat pump monitoring requirements were also finalised under the Addendum. One scheme, Efficiency Plus Heat Pump, had been approved but could not proceed in 2023/24 because those requirements were still being settled; it was delivered in 2024/25. The stated purpose of the technical monitoring was to assess how the systems performed in real homes in Northern Ireland, to compare this with wider evidence and to identify lessons for future deployment¹.

"The main changes to highlight in the Addendum (dated Feb 2024) to the NISEP 2023/25 Framework Document were as follows"

The report gives the outturn for the year in which the changes took effect. Total NISEP spend on schemes was £7,662,216 against an initial fund of £7,941,946, with an underspend of about £258k carried forward into 2025/26¹.

Of the total spend, £1,090,452, or 14%, went to Priority Innovative Domestic schemes, up from 10% in 2023/24 and a funding increase of £360k. Three innovative schemes delivered 374 energy efficiency measures across 148 properties, including 14 air source heat pumps¹. The report records that one Primary Bidder withdrew two innovative heat pump schemes during the year, the same two it had withdrawn in 2023/24, and that the Make it Cosy scheme, which accounted for £181k of spend in 2023/24, was withdrawn and so was not included in 2024/25 allocations¹.

Why it matters for households

NISEP support is delivered through schemes bid for by Primary Bidders, not by direct application from households, so the Addendum changes the terms on which installers and bidders bring work to homes rather than the route a household takes. The income eligibility change affects which lower-income households schemes can target, and the cavity wall cap changes affect how much extraction and refill work can be funded within a scheme's allocation¹.

The heat pump monitoring requirement means installations delivered under the affected scheme carry measurement of how the system performs in the home. For a household, that sits alongside the UK heat pump policy and targets framework rather than replacing it. The report notes that rising delivery costs, including labour, materials, overheads and changes to the National Minimum Wage, continued to influence installation rates, and that the number of measures delivered fell by 2,251 year on year, largely because of a reduction of 2,064 LED measures¹.

What happens next

Incentives are no longer payable and have been removed from future NISEP schemes commencing 1 April 2025. Because of the level of competition within NISEP, cost effectiveness targets will no longer be calculated for NISEP 2025/27 schemes, and the Utility Regulator will no longer award an incentive payment to Primary Bidders¹. No further changes to the framework beyond those in the February 2024 Addendum have been reported.

Sources1 cited

1. [](https://www.uregni.gov.uk/files/uregni/documents/2026-07/2024-25%20NISEP%20Annual%20Report.pdf), uregni.gov.uk