The latest revision of the PAS 2035 and PAS 2030 retrofit standards was published in September 2023 and is freely available for download, according to a government review of the barriers to adapting historic homes1. The same publication date is given in a Department for Energy Security and Net Zero consultation on mid-scheme changes to the Energy Company Obligation 4 (ECO4) and the Great British Insulation Scheme (GBIS), which states that "In September 2023 a new version of PAS 2035/2030 was published"2. The National Insulation Association repeats that wording in its consultation response3.
The 2023 edition is subject to an 18-month transition process, and the transition period between PAS 2035/2030:2019 and PAS 2035/2030:2023, as consulted on by BSI, ends on 30 March 20252. DESNZ proposed making legislative amendments to replace references to PAS 2035/2030:2019 with PAS 2035/2030:20232.
DESNZ's cost assumption for compliance with the 2019 processes is £1,030 per property retrofit, in 2023 prices, for both ECO4 and GBIS2. The National Insulation Association told the consultation that compliance costs "can vary significantly from £500, £1200 per install", and that for multi-measure projects between £900 and £1,100 is a fair representation of market rates for retrofit assessment, design, coordination and lodgement3. The association also said it had seen day rates of up to £500 for site presence on Social Housing Decarbonisation Fund projects3.
The consultation also set out proposals for an alternative installation standard to PAS 2035/2030 for specific measures under GBIS, with TrustMark consulting on how TrustMark Licence Plus could be adapted for loft insulation delivered as a single measure, and heating controls when paired with it2. The National Insulation Association said it agreed that ECO4, as a multi-measure scheme including more complex and higher risk measures, needs the quality assurance and risk management process set out in PAS 20353.
"The latest revision to the PAS 2035/2030 documents was published in September 2023 and is freely available for download"
Why it matters for households
PAS 2035 and PAS 2030 are the standards that govern how retrofit work is assessed, designed, installed and signed off. The 2023 revision is the version now in use, and its free availability means the document itself is not a cost barrier to reading it. What households encounter in practice is the compliance cost attached to following it: DESNZ puts that at £1,030 per property retrofit for ECO4 and GBIS2, while the insulation industry body reports a range of £500 to £1,200 per install3. Those figures sit inside grant-funded work rather than being paid directly by the householder, but they shape how much of a scheme's budget reaches the fabric of a home.
The standards also determine who must be involved. Under PAS 2035, a retrofit coordinator and a qualified retrofit designer take part, which the National Insulation Association says the TrustMark Licence Plus route for GBIS would not require3. For a home's energy independence, the practical effect is that the route taken to a measure, and the paperwork around it, can differ between schemes even where the physical work is similar.
The government review notes that over half (54%) of owners and occupiers of listed homes think it is difficult to find reliable guidance about how to retrofit them1. The same review records that some historic buildings are exempt from having an Energy Performance Certificate where complying with minimum energy efficiency requirements would require installing recommendations that would unacceptably alter their character or appearance1.
What happens next
The transition period between the 2019 and 2023 editions of PAS 2035/2030 ends on 30 March 20252. DESNZ's consultation on ECO4 and GBIS mid-scheme changes was issued on 14 November 2024 with a response deadline of 12 December 20242. ECO4 and GBIS are both due to end on 31 March 20262. The outcome of the proposed legislative change of references from the 2019 to the 2023 edition has not been reported in these documents.
Sources3 cited
- Adapting historic homes for energy efficiency: a review of the barriers - GOV.UK, gov.uk
- Energy Company Obligation 4 and the Great British Insulation Scheme: mid-scheme changes - consultation - GOV.UK, gov.uk
- Consultation Response - Energy Company Obligation 4 & the Great British Insulation Scheme: Consultation on mid-scheme changes - National Insulation Association, nia-uk.org