ECO and Household Energy Efficiency Statistics

Every loft insulated, every cavity wall filled and every heating measure fitted under a government obligation scheme ends up counted in one place: the Household Energy Efficiency Statistics. These are accredited official statistics covering England, Scotland and Wales, and their core record is the number of measures installed under the Energy Company Obligation (ECO) and the Green Deal schemes¹. The June 2026 headline release is the current edition of a series that has run in essentially the same form since at least December 2015¹.

The numbers matter to householders for a simple reason. ECO is the scheme under which energy companies install insulation and heating in homes, often at no cost to the occupier, and the statistics are the only official record of how much of that work has actually happened, where, and what it is estimated to save. The detailed releases carry more than the headline counts: as of December 2022, 69,200 measures had been installed under ECO3 Interim and ECO4, and since the start of ECO an average of 1.47 measures were installed per household receiving measures³.

Scope of the domestic energy efficiency data

The Household Energy Efficiency Statistics are the government's running count of energy efficiency measures installed in homes under its obligation schemes. Each headline release states the same core coverage: "This release includes measures installed under the Energy Company Obligation (ECO) and the Green Deal schemes." That wording appears identically in the June 2026 release, the October 2022 release, the May 2018 release and the December 2015 release, which shows how stable the series definition has been across a decade¹.

Two things follow from that definition. First, the statistics count measures, not households alone: a home receiving loft insulation and a new boiler counts as two measures, which is why the average works out at 1.47 measures per household receiving them since the start of ECO³. Second, the series includes the Green Deal even though that scheme is long closed to new finance, so the totals are a cumulative historical record rather than a count of current activity. Earlier ECO phases are folded in the same way: Ofgem's consumer FAQs record that measures installed up to 31 March 2017 are covered by a separate earlier set of FAQs, marking where the older phases sit in the record⁷.

The releases are accredited official statistics, a status confirmed in the December 2015, October 2022 and June 2026 editions alike, and the figures are provisional and subject to future revisions⁴. For a householder trying to judge whether an installer's claim about ECO work in their area stacks up, this series is the reference point. Our guide to reading UK energy statistics explains what official status and revision mean in practice.

Data sources and publication schedule

The statistics are compiled by the government department responsible for energy policy, today the Department for Energy Security and Net Zero (DESNZ), which inherited the role from its predecessor department. The headline releases appear on gov.uk on a regular cycle: the detailed release of March 2023 recorded that the next headline release was planned for 20 April 2023 at 9.30am, containing ECO measures up to the end of February 2023, which indicates a roughly quarterly rhythm with a two month lag between installation and publication³.

The same department publishes the wider family of statistics that surround the household efficiency numbers:

• The National Energy Efficiency Data-Framework (NEED), whose impact of measures data tables "assess the impact of installing home efficiency measures such as loft insulation on household energy consumption"⁸
• Energy Performance Certificate statistics for England and Wales, drawn from certificates issued for domestic and non-domestic buildings since 2008⁹
• The DESNZ Public Attitudes Tracker, which "tracks public awareness, attitudes and behaviours relating to the policies of the Department for Energy Security and Net Zero (DESNZ), such as energy and climate change"¹⁰
• UK local authority and regional greenhouse gas emissions statistics, whose main data sources are the UK National Atmospheric Emissions Inventory and the DESNZ official statistics on energy consumption for local authority areas¹¹

The Household Energy Efficiency series sits within this landscape as the record of obligation scheme delivery specifically. It is worth noting the territorial limit: the releases apply to England, Scotland and Wales, so Northern Ireland's housing stock is counted in separate statistics, including the Energy Performance Certificate data published by nidirect¹².

Installed measures, their costs and the savings achieved

The headline count of measures is only the opening layer. Each release also carries, in its own words, "further analysis and geographical breakdowns of ECO measures, ECO delivery costs, estimated carbon and energy savings from measures installed and the supply chain"¹. The same four analytical strands appear in the October 2022 and December 2015 releases, so the structure has been consistent throughout the series⁴.

The delivery cost analysis is the official record of what ECO measures actually cost to install, which is a question householders ask constantly when quoted prices privately. The carbon and energy savings figures are estimates rather than metered readings, and they feed a wider evidence base: NEED's impact of measures analysis matches homes that received a measure against consumption data to assess what actually changed⁸. The Green Homes Grant Local Authority Delivery and Home Upgrade Grant release shows the same analytical pattern for those schemes, covering measures installed, homes upgraded, installation rates, installations by region, local authority and parliamentary constituency, carbon, bill and energy savings, and changes in Energy Performance Certificate¹³.

The supply chain analysis rounds out the picture by showing which types of business are doing the installation work. Together these strands let a reader see not just how many measures went in, but what they cost, what they are estimated to save, and who delivered them, which is the evidence base behind our page on what home energy installations have cost over time.

Breakdowns by region, local authority and constituency

The geographical breakdowns are among the most used parts of the releases, because they let a householder, a council or a community group see what has actually been installed in their area. The ECO measures are broken down geographically in every headline release¹, and the Green Homes Grant Local Authority Delivery release shows the level of detail available: installations by region, by local authority and by parliamentary constituency¹³.

The same local geography underpins other official series that a reader may want alongside the ECO numbers. The UK local authority and regional greenhouse gas emissions statistics, covering 2005 to 2024, are built on the DESNZ energy consumption statistics for local authority areas¹¹, and Energy Performance Certificate statistics record the efficiency of the buildings being sold and let in each area⁹. In Scotland, the Scottish House Condition Survey 2024 provides the housing stock evidence for that nation, including the Energy Saving Trust's estimate that "an un-insulated dwelling loses a third of all its heat through the walls and a further quarter through the roof"¹⁴.

For householders, the practical value is being able to check a claim. If a doorstep seller says ECO work has transformed your street, the geographical tables are the independent record. Our pages on regional and local authority energy consumption and fuel poverty statistics by local area carry the neighbouring datasets.

Verifying that ECO measures are delivered

The measure counts are only as good as the verification behind them, and ECO has a formal quality assurance chain. Under the current ECO4 guidance, "TrustMark's Framework requires compliance and certification with PAS 2035:2023 for all relevant ECO measures"⁵. PAS 2035 is the standard governing how retrofit work is specified and installed, so the requirement ties every relevant ECO measure to a recognised process rather than to an installer's own word.

The lodgement rules are explicit. The guidance states that "All ECO4 measures (except DHC measures) must be lodged with TrustMark (or an equivalent) and delivered by a TrustMark (or an equivalent) registered business"⁵. DHC refers to district heating connections, which follow a different route. The same rules were set out in the 2022 draft guidance, which added that TrustMark "will be reviewing the quality assurance process and have full oversight of the monitoring process for ECO measures"¹⁵. Suppliers must also retain evidence of what was installed, including "Mid and post-install photographic evidence (geotagged and time-stamped/dated) which clearly shows the specific product installed or being installed"⁵.

For a householder, this means an ECO measure is not counted until it has been lodged with TrustMark by a registered business working to PAS 2035:2023. That is the same lodgement record that, from the August 2026 Warm Homes statistics onwards, may be used to complete incomplete grant recipient records, showing how the verification data is shared across schemes¹⁶.

Other statistics in this field

The Household Energy Efficiency Statistics are not the only official count of home energy work. The Warm Homes: Local Grant statistics, first published in May 2026 and updated in August 2026, cover measures installed under that scheme in domestic properties in England, with analysis on measures installed and homes upgraded¹⁷. A methodology note published alongside the August 2026 releases sets out how those statistics are compiled¹⁸.

Alongside the obligation and grant schemes sit the certification records. The Microgeneration Certification Scheme (MCS) publishes installation data including statistics on domestic and existing installations, such as the domestic retrofit battery installation figures for 2025 to 2026, with a contact address at DESNZ for the data¹⁹. Our pages on MCS installation statistics, heat pump installation statistics and home battery storage installation statistics cover those records in detail.

The wider family also includes the Energy Performance Certificate statistics for England and Wales, covering certificates on domestic and non-domestic buildings constructed, sold or let since 2008⁹, and the energy efficiency characteristics of new dwellings, published as official statistics in development²⁰. In Scotland, the Energy Performance of Buildings regulations update in 2025 set out the government response on EPC reform, including work on a Heat Retention Rating with Band C set between 71 and 120 kWh/m2/year of energy used to heat the home, under which around 80% of homes currently at EPC C also achieved Band C on the HRR in a tested sample²¹. The pillar page for this site's market data maps how all these series fit together.

Advice services and the Energy Saving Trust

The Energy Saving Trust is the independent body that sits alongside these schemes as the advice layer rather than a delivery counter. Councils including Torridge direct residents to it for "free and impartial advice on how to reduce carbon emissions, how to use water more sustainability and how to save money on energy bills"²², and Edinburgh Council points households to its advice on energy at home and its guide to green renovation, room by room²³.

The Trust also produces its own figures, and it is candid about their nature: "We produce indicative statistics to support these decisions and to explain the assumptions behind them." Its savings, cost assumptions and methodology are reviewed at least annually, and updated more often where market conditions or official datasets change significantly; typical installation costs are updated every year using data from the previous 12 months²⁴. Its figures draw on housing stock data from DESNZ statistics, U-values from the Standard Assessment Procedure, government in-use factors and the heat replacement effect²⁴.

Two of its figures are widely quoted. The Trust states that "using heating controls will help the average semi-detached house save £100 each year in GB and £110 in NI" with a full set installed, and that "Around 26% of an uninsulated home's heat will escape through the roof"²⁵. These are indicative estimates, not metered results, and the Trust says so. That honesty about method is what separates advice from marketing, and it is why its figures are quoted inside official documents such as the Scottish House Condition Survey¹⁴.

Scottish delivery roles and withheld information

In Scotland the Trust has a delivery role as well as an advice one. The Home Energy Scotland Grant and Loan Scheme, which helps eligible homeowners pay for energy efficiency improvements and clean heating systems, "is run by the Energy Saving Trust (EST) on our behalf", in the Scottish Government's own words²⁶. The Trust was awarded its current contract through a competitive tender exercise, with the initial term running from 1 December 2023 until November 2026²⁷.

How much the Trust is paid for that work is not public. Two freedom of information responses, one from January 2025 and one from July 2025, both confirm that the amount paid to the Trust for managing heat and energy efficiency schemes, and for administering the grant and loan scheme from December 2023 onwards, was withheld under Regulation 10(5)(e) of the Environmental Information (Scotland) Regulations, the exception covering confidentiality of commercial or industrial information²⁷. The payment figure therefore does not exist in the public record, and any number quoted elsewhere should be treated as unsourced.

Other delivery in Scotland sits with local authorities: the Energy Efficient Scotland Area Based Schemes were supported by Scottish Government funding and "delivered by local authorities"²⁹. Scottish legislation also names the Trust in a register holding role, describing "a register held by a non-public body"³⁰. For householders, the practical route to advice in Scotland is Home Energy Scotland, which "can also offer free advice on improving the energy efficiency of your home"²³, and the Trust's helpline on 0300 123 1234²².

Household energy independence and what the figures show

These statistics are, at root, the national account of how much of Britain's housing stock has been made less dependent on bought energy. Every insulation measure recorded in the series reduces the heat a home loses: with a third of heat escaping through uninsulated walls and a further quarter through the roof¹⁴, the measures counted here are the ones that close those routes. Heating controls, saving an estimated £100 a year in Great Britain and £110 in Northern Ireland for an average semi-detached house²⁵, cut waste without changing the building.

The independence lens also shows the limits. ECO measures reduce how much energy a home needs, but the home remains dependent on the energy supplier for what it still buys, and the scheme itself is delivered through obligated energy companies rather than by householders choosing freely. The verification chain, TrustMark lodgement under PAS 2035:2023⁵, gives quality assurance, but the householder's recourse runs through the registered business and the supplier, not through the statistics themselves. The savings figures are estimates, marked as such by both government and the Energy Saving Trust¹.

What the statistics give a household is evidence: a way to check what has been installed locally, what it cost, and what it is estimated to save, before committing money of their own. Used alongside the EPC statistics, the fuel poverty statistics and the public attitudes tracking data, they form the factual ground under almost every claim a householder will hear about home energy improvement.