Ofgem's Access Significant Code Review decision provides that, from April 2023, the costs of network reinforcement associated with installing low carbon technologies in existing buildings will normally be socialised1. The change applies to reinforcement work triggered by such installations, rather than to the cost of the equipment itself.
The decision sits alongside other regulatory work on the low carbon heating market. The Competition and Markets Authority published a findings report in May 2023 on consumer protection in the green heating and insulation sector1. The same body of work covers support schemes in the devolved nations, including the Scottish Government's Home Energy Scotland Grant and Loan, which prior to June 2024 supported applications for energy storage systems, including heat batteries1.
Support arrangements differ by nation. The Scottish scheme provides a £7,500 grant and up to £7,500 of loan funding for wood fuelled (biomass) boilers and eligible stoves, though it does not support non-automated, non-pellet stoves or room heaters, and written evidence must be provided as to why a heat pump and high retention storage heaters are not suitable1. The UK Government's Boiler Upgrade Scheme, which covers England and Wales, offers grants of £5,000 towards a biomass boiler for properties off the gas grid and in rural locations, with the boiler required to hold an emissions certificate showing that polluting emissions are kept to a minimum1.
In Northern Ireland, the Department for the Economy consulted on support for low carbon heating in residential buildings. The Energy Saving Trust's response recommended that air-to-air heat pumps be added to the technologies considered for support, noting that there are housing types for which air-to-water, ground-to-water and water-to-water heat pumps are not suitable but air-to-air heat pumps are, for example flats1. It also suggested heat batteries be considered where no heat pump technology is technically feasible, and biomass boilers in exceptional circumstances, such as rural properties where peak heat demand cannot be met by a heat pump without upgrading the electricity supply at a disproportionate cost1.
"We agree that a minimum Seasonal Co-efficient of Performance of 2.8 should be applied to the heat pump technologies considered for support."
The response also supported the proposal that hybrid heat pumps should not be supported as part of a low carbon heat scheme at present, and recommended that products and installations covered by MCS should be MCS certified1.
Why it matters for households
Network reinforcement is the work needed when a local electricity network must be upgraded to carry more load, for example when a heat pump or other low carbon technology is installed in an existing home. Under the socialised approach, the cost of that reinforcement is spread across the wider customer base rather than falling on the individual household whose installation triggered it1. For a home considering a low carbon technology, that changes the shape of the upfront cost: the connection or reinforcement charge that might otherwise appear on a single quote is, in normal cases, no longer borne by that one property.
The practical effect on a home's energy independence depends on what is installed and how it is run. A heat pump or heat battery reduces reliance on delivered gas or other fuels, but it increases reliance on the electricity network, and the capacity of that network in rural areas is a stated constraint in the Northern Ireland consultation material1. Where the network cannot meet peak demand without disproportionate upgrade cost, the alternatives discussed include biomass and, in limited cases, hybrid systems1.
Support levels and eligibility conditions vary by nation, and the Northern Ireland proposals remain proposals. The Energy Saving Trust response was published on 3 July 2025 and the page carrying it was last updated on 22 April 20261.
What happens next
The Northern Ireland consultation response sets out positions rather than decisions; no outcome from that consultation is reported in the material1. The Scottish Government is considering the implications for the Home Energy Scotland Grant and Loan Scheme after publication of the updated Heat Pump Design Standard, which clarifies MCS requirements for a hybrid heat pump1.
Sources1 cited
- Low carbon heating in residential buildings - Energy Saving Trust, energysavingtrust.org.uk