The consultation on mid-scheme changes to the Energy Company Obligation 4 (ECO4) and the Great British Insulation Scheme (GBIS), run by the Department for Energy Security and Net Zero (DESNZ), closed on 12 December 20241. The National Insulation Association (NIA), which represents installers, system certificate holders and manufacturers of insulation solutions, submitted a response1.
The NIA supported allowing a household to receive both loft and cavity wall insulation under GBIS, a change from current rules under which a home needing both a loft insulation top up and cavity wall insulation would be allowed only one of these measures1. The association argued that about one-third of all the heat lost in an uninsulated home escapes through the walls, and that a home with uninsulated solid walls could be losing 45% of its heat through the walls1. It added that up to 15% of the heat in a room can be lost through uninsulated floors, and that air infiltration through a sash window in good condition can be reduced by as much as 86% by adding draughtproofing1. The NIA said the multi-measure approach should be extended to any combination of insulation measures recommended on a valid retrofit assessment1.
On compliance costs, the NIA said costs can vary significantly from £500 to £1,200 per install, against a consultation forecast of approximately £400 to £500 for compliance with the TrustMark Licence Plus (TMLP) processes1. It noted that DESNZ's cost assumption for compliance with PAS 2035/2030:2019 processes is £1,030 per property retrofit, in 2023 prices, for both ECO4 and GBIS, and that for multi-measure projects between £900 and £1,100 is a fair representation of market rates for retrofit assessments, design and coordination services and lodgement1. A new version of PAS 2035/2030 was published in September 20231.
The NIA agreed that projects meeting the ECO4 rules should count towards an obligated supplier's GBIS obligation, subject to safeguards against double counting, and agreed with a conversion factor if GBIS is to remain within its overall budget of £1 billion1. It did not support limiting the proportion of GBIS obligations that can be achieved through delivery under ECO4 rules1. On smart meters, the NIA noted the Government's statement in the consultation that 64% of homes already have smart meters, and said it is important that the Government makes a concerted effort to roll out smart meters to the remaining 36% of households that do not currently have them1.
"As an industry trade association, we will not be participating directly in ECO4 and GBIS PFP. However, many of our members are planning to participate in PFP."
Why it matters for households
ECO4 and GBIS are the two main routes by which energy suppliers fund insulation and other efficiency measures in homes, so the rules set here decide what a household can actually receive. The NIA's central point is that a single-measure approach can leave major sources of heat loss untreated, meaning a home may remain cold and its bills high even after support1. Allowing both loft and cavity wall insulation under GBIS, and letting ECO4 projects count towards GBIS obligations, would change what is available to eligible homes. The compliance cost figures matter to households indirectly: they are part of what determines whether installers find the work viable, and the NIA states that high fixed costs on single low cost measures can make GBIS unprofitable for installers, leading to a shortage of those willing to work on it1. The smart meter proposals affect which homes can be included in the eligible pool for ECO4 performance-based funding1.
What happens next
The consultation closed on 12 December 20241. The NIA's response was published on 17 December 20241. No date for the Government's response to the consultation has been reported1.