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Energy: evidence and policy appraisals

Detailed research records, alternatives, costs and provisional assessments. These records preserve different scopes and historical reviews; they are not an additional ranked action plan.

Evidence → choices → outcomes

What could improve it?

Affordable, reliable energy for households in Great Britain, with less exposure to volatile gas prices.

These options link to their national assessment, including funding, delivery constraints and remaining uncertainties.

  • Assessed option · provisional

    Connect the power Britain needs

    8/10 criteria scored

    Coverage of the appraisal, not an impact score.

    Delivery: Red

    Whole-life costs incomplete

    Evidence and delivery constraints

    Engineering need and queue evidence exist; the marginal effects of queue reform and industrial bill relief are different questions.

    Separate queue management, network reinforcement and industrial levies; identify projects, kit, engineers and regulator decisions.

  • Assessed option · provisional

    Warm homes, inspected before payment

    Health-linked selection, independent inspection before payment and an evaluation inside the Warm Homes grants.

    9/10 criteria scored

    Coverage of the appraisal, not an impact score.

    Delivery: Amber

    Whole-life costs incomplete

    Evidence and delivery constraints

    Energy-saving evidence does not evaluate inspection-before-payment or prove health outcomes for this package.

    Target poor-quality homes; survey suitability/ventilation; use qualified installers and independent inspection; establish redress.

  • Assessed option · provisional

    Change how utilities fund investment and share the risks

    7/10 criteria scored

    Coverage of the appraisal, not an impact score.

    Delivery: Red

    Whole-life costs incomplete

    Evidence and delivery constraints

    Site scenarios are not demonstrated savings. Price controls, insolvency, refinancing and asset ownership have different counterfactuals.

    Separate sectors and instruments; assess legal/regulatory powers, financing, compensation, investment and service quality.

This domain in the UK SWOT →UK National Action Plan →

How we assessed these options

What would it take to improve this?

Detailed policy appraisal

The outcome we want: Affordable, reliable energy for households in Great Britain, with less exposure to volatile gas prices.

The main constraint: Bills are mostly wholesale and network costs that no single reform removes; lowering them for good needs insulated homes and electric heating, which depend on skilled installers, quality checks and a pricing decision by DESNZ and the Treasury about who pays.

Constraint type: workforce, market structure, money, public consent.

The options on the table

What is funded now, and the changes assessed against it — the current baseline and the alternatives, before the position today and the actions.

Provisional single-reviewer assessments from the 6 October 2026 review; not approved business cases, and not government policy.

  • Connect the power Britain needsDelivery risk: Red

    Funded now
    Baseline: Ofgem approved the connections reform (Gate 2 firm queue) on 15 April 2025; NESO and the networks are issuing offers (Phase 1 deadline extended to 31 October 2026); Great British Grid was announced on 29 September 2026; industrial price relief (BICS) opens from April 2027. Enforcing the timetable and publishing time to connect as a regular measure is a UK Facts proposal, not government policy.
    The change assessed
    Not yet defined.

    Range if completed: 13.0–19.0 out of 30 (equal weights; not yet assessed: expected incremental benefit (Bn), incremental affordability (Co))

  • Warm homes, inspected before paymentDelivery risk: Amber

    Funded now
    The Warm Homes Plan allocates £4,422m of low-income home grants for 2025–26 to 2029–30. The proposal here is targeting by need plus quality assurance, within that programme.
    The change assessed
    Health-linked selection, independent inspection before payment and an evaluation inside the Warm Homes grants.

    Range if completed: 17.0–20.0 out of 30 (equal weights; not yet assessed: incremental affordability (Co))

  • Change how utilities fund investment and share the risksDelivery risk: Red

    Funded now
    Not yet stated in the record.
    The change assessed
    Not yet defined.

    Range if completed: 9.0–18.0 out of 30 (equal weights; not yet assessed: increment beyond baseline (Ad), expected incremental benefit (Bn), incremental affordability (Co))

Alternatives already on record: 33 options listed under the points in the position today (23 without an action record), and 4 earlier options under other options compared. They have not been scored in the review.

The position today

  • What we can build on (3)
  • What is holding us back (5)Random audits of previously unaudited ECO4/GBIS installations estimated major or Category 1 non-compliance in 98% of external and 29% of internal wall insulation. The NAO identified oversight failures. Extending ECO4 gives time for repair; it does not establish that homes have been put right. (2025 statistical audits; ECO4 extension to December 2026 · Great Britain)
  • What could improve things (1)Quality-assured upgrades for the least efficient homes, and electricity prices that reward clean heating, could lower bills and gas exposure together.
  • What could make it worse (2)

Which quadrant a point sits in is our analytical judgement, not a statistical category. Each point says whether it is a measured fact, our synthesis or a risk.

What we can build on Strengths

  • The Warm Homes Plan allocates £4.4bn of grants for low-income homes over five years, within £15bn of public investment.

    Measured factConfidence: High· 2025–26 to 2029–30· England

    Source: Department for Energy Security and Net Zero, Warm Homes Plan (updated 18 March 2026) (Funding allocations table; Chapter 3)

    Options assessed against this point: Warm homes, inspected before payment (Amber delivery RAG)

    What government has committed to

    Funding: The Warm Homes Plan commits £15bn of public investment to upgrade up to 5 million homes by 2030, including £4,422m of low-income homes grants over 2025-26 to 2029-30, and aims to lift up to a million households out of fuel poverty by 2030.

    Who and when:
    Starmer government (to July 2026), 21 January 2026.
    Since 20 July 2026:
    Kept by the Burnham government. Re-stated under Burnham: DESNZ on 27 August 2026 said 'the Warm Homes Plan will help roll out clean technology to millions'; Energy Secretary Fahnbulleh's 1 October 2026 release says 'Our Warm Homes Plan will also lower bills for millions of households and help lift households out of fuel poverty'. No change to the funding table found. Source: HM Treasury, Energy bill tax cut starts today to give families breathing space (Body ('This week the Prime Minister committed to reduce energy costs so that they are in line with other countries in Europe within ten years'; Fahnbulleh quote on £150 removed earlier this year; Warm Homes Plan)).
    Source:
    Department for Energy Security and Net Zero, Warm Homes Plan (updated 18 March 2026) (Executive summary; 'Warm Homes Plan funding allocations (£ millions)' table (low-income homes grants 4,422); 'Support for low-income households'; 'Improving quality and consumer protection'; 'Making electricity cheaper')

    Checked 4 October 2026. A commitment is not delivery.

    Options (3)
    • ShortlistedFix cold and inefficient homes with quality-assured work

      Target the £4.4bn of low-income grants by need and building suitability, with property assessment and post-installation checks.

      Who: DESNZ, councils, housing associations and accredited installers · Evidence: Observational analysis · Status: Funded programme

      Source: Department for Energy Security and Net Zero, Warm Homes Plan (updated 18 March 2026) (Executive summary; 'Warm Homes Plan funding allocations (£ millions)' table (low-income homes grants 4,422); 'Support for low-income households'; 'Improving quality and consumer protection'; 'Making electricity cheaper')

    • Move low-income grants to a single area-based scheme from 2027-28

      Integrating WH:SHF and WH:LG into one area-based programme, coordinated with network operators, aims to reach more fuel-poor homes per pound.

      Who: DESNZ with local authorities and DNOs · Evidence: Untested proposal · Status: Announced proposal

      Source: Department for Energy Security and Net Zero, Warm Homes Plan (updated 18 March 2026) (Executive summary; 'Warm Homes Plan funding allocations (£ millions)' table (low-income homes grants 4,422); 'Support for low-income households'; 'Improving quality and consumer protection'; 'Making electricity cheaper')

    • Evaluate delivery against comparison homes

      Measure gas savings and fuel-poverty exits against similar homes, as the SHDF Wave 1 evaluation did (1,079.9 kWh a year saved; about £97 a year).

      Who: DESNZ (evaluation) · Evidence: Experimental or quasi-experimental evaluation · Status: Site-editorial action

      Source: Department for Energy Security and Net Zero, Social Housing Decarbonisation Fund Wave 1: impact evaluation - report (Executive summary, 'Energy, bill and carbon savings' (1,079.9 kWh gas saved vs comparison homes; £97 a year; only 33% of residents reported lower bills) and 'Resident outcomes')

  • Most policy costs have already moved off bills onto taxation: since April 2026 they are about a tenth of a typical bill.

    Measured factConfidence: High· From April 2026· Great Britain

    Source: UK Energy Research Centre, The Cost of Electricity in the UK: Drivers, Challenges and Opportunities for Reform (UKERC Briefing Paper) (“Bills post-Budget” (p.15))

    What government has committed to

    Funding: From April 2026, 75% of the domestic Renewables Obligation is funded by the Exchequer for 2026-27 to 2028-29 and the Energy Company Obligation ended on 31 March 2026, taking about £150 off a typical bill; the Fuel Poverty Strategy puts the RO shift at £7bn over three years.

    Who and when:
    Starmer government (to July 2026), 26 November 2025.
    Since 20 July 2026:
    Kept by the Burnham government. Acted on and re-stated under Burnham: the RO to Exchequer scheme reported £520.7m of spending for April-June 2026 (10 Sep 2026); Fahnbulleh (1 Oct 2026) cited 'the £150 of costs we removed from bills earlier this year'. Source: Department for Energy Security and Net Zero, The Renewables Obligation to Exchequer Scheme Expenditure: 1 April to 30 June 2026 (Opening paragraphs (scheme in effect 1 Apr 2026, runs 3 years, removes 75% of RO costs); expenditure table (£520,709,288.19 in Q1)).
    Source:
    Department for Energy Security and Net Zero, What does the Autumn Budget mean for your energy bills? ('Where is the saving coming from?' (ECO ends 31 Mar 2026; 75% of RO from general taxation from 1 Apr 2026); 'How did we calculate the £150 cost saving?')

    Checked 4 October 2026. A commitment is not delivery.

    Options (3)
  • Electricity is far cleaner than it was: low-carbon sources generated 64% of UK electricity in 2025, against 25% in 2000; none came from coal in 2025; and each kilowatt-hour supplied carried 147g of CO2 in 2025, against 476g in 2000.

    Measured factConfidence: High· 2000 to 2025· United Kingdom

    Source: Ember, Yearly electricity data (generation by source) (Generation (TWh): Clean; Total generation — United Kingdom); Department for Energy Security and Net Zero, Digest of UK Energy Statistics (DUKES) 2026: Chapter 5 — Electricity (Table 5.6 (coal) and Table 5.14 (carbon intensity))

    What government has committed to

    Target: The Clean Power 2030 Action Plan sets a pathway to a clean power system by 2030.

    Who and when:
    Starmer government (to July 2026), 13 December 2024.
    Since 20 July 2026:
    Not confirmed either way since the change of Prime Minister on 20 July 2026. Burnham-government releases refer to a “transition to clean power” and announced a Great British Grid on 29 September 2026, but none restates 2030 as a dated target; the Prime Minister said in September 2026 that he is determined to reach net zero by 2050 (press reports).

    Checked 4 October 2026. A commitment is not delivery.

    Options (2)
    • Connect built and consented low-carbon generation to the grid faster

      More of the clean power already built reaches customers; the page’s grid-connections option covers the reforms.

      Who: NESO, Ofgem and DESNZ · Evidence: Untested proposal · Status: External proposal

    • More fixed-price contracts, storage and interconnection so gas sets the price less often

      Passes more of the lower running cost of clean power through to bills.

      Who: DESNZ and Ofgem · Evidence: Untested proposal · Status: External proposal

What is holding us back Weaknesses

What could improve things Opportunities

What could make it worse Threats

The actions worth examining

Our shortlist for this page. Research quality, policy status, cost and funding are judged separately; none of these is government policy unless its status says so.Our shortlist. None is government policy unless its status says so.

  1. Warm homes, inspected before payment — programme funding exists; project allocation unconfirmed
  2. Make electricity pricing support cheaper clean heating — not yet costed / funding not identified
  3. Connect the power Britain needs — not yet costed / funding not identified
  • Action 1A18Policy status: funded programme

    Warm homes, inspected before payment

    Target insulation, heating and ventilation at households in greatest need, with a property survey before work and checks after it.

    Assessment (draft, 6 October review)

    Who decides:
    DESNZ and MHCLG, with councils, landlords and accredited installers (England)
    Evidence:
    Observational analysis. Official before-and-after comparisons show energy savings; the health evidence is an older review with uncertain effects.
    Expected effect:
    −17% median gas use: gas use in homes after solid wall insulation (England and Wales). Observational comparison, mostly from government schemes; savings for cavity and loft insulation are smaller.
    Cost and funding

    £4.42bn in total, 2025–26 to 2029–30, price basis not stated by the source; 1 further cost line, some not yet costed

    Funding: Programme funding exists; project allocation unconfirmed

    Why it is shortlisted here: Lowers the energy a home needs, with funding already allocated; quality assurance is the missing piece.

    What it takes
    The problem

    Cold, inefficient homes push up bills and can harm health, and poor installations can make homes worse.

    Who is affected, and where

    Low-income and fuel-poor households in inefficient homes, in England. Territory: England. Warm Homes Plan grants are England-focused; devolved arrangements were to be set out separately; Scotland and Wales run their own schemes.

    Policy status

    A funded programme already exists. The Warm Homes Plan allocates £4,422m of low-income home grants for 2025–26 to 2029–30. The proposal here is targeting by need plus quality assurance, within that programme.

    The evidence
    What the research found:
    Solid wall insulation cut median gas use by 17% in 2024 for measures installed in 2023 (indicative). The Cochrane review found health improvements “are possible”, clearest where homes were inadequately warm.
    Evaluated on:
    Homes with measures installed under government schemes (energy); people in improved homes in 39 studies (health); England and Wales, 2023–24 (energy); several countries to 2012 (health)
    Our recommendation (separate from the research):
    Select homes by need and suitability, fund surveys and post-installation checks, and measure weather-adjusted use and indoor conditions.
    Strongest counter-evidence:
    Savings vary year to year and include households choosing to heat more; health effects are uncertain and the review is old.
    Effects on record
    • Gas use in homes after solid wall insulation: −17% median gas use (similar homes without measures; 2024 savings for measures installed in 2023; indicative; varies year to year and includes households choosing to heat more). evaluated, moderate confidence; England and Wales. Observational comparison, mostly from government schemes; savings for cavity and loft insulation are smaller.
    • General, respiratory and mental health of residents: Direction plausible; size not established. evaluated, limited confidence; Studies in several countries, searched to 2012. The review says improvements “are possible”, clearest where warmth was inadequate; no current UK estimate and no cashable NHS saving.
    • Low-income households counted as fuel poor: Direction plausible; size not established. plausible spillover, limited confidence; England. The fall in the headline count partly follows from the definition. Whether hardship actually falls depends on real bills, heating behaviour and prices, which the count does not measure.
    • Damp and mould after poorly specified or installed insulation: A cost or harm; size not established. plausible spillover, limited confidence; England. This is why A18 pairs grants with a survey before work and checks after it. No national rate of defects is published in the sources we checked.
    Cost and funding

    Cost completeness: Published programme envelope; project costs still needed. Funding: Programme funding exists; project allocation unconfirmed.

    • Warm Homes Plan: low-income home grants (capital; paid by central government): £4.42bn in total, 2025–26 to 2029–30, price basis not stated by the source. Grant line only; the plan’s loans and financial transactions are different kinds of money and are not included. No price basis stated.
    • Property surveys, installation quality checks, remediation and monitoring (recurring spending; paid by central government, landlords, households): Not yet costed. Use surveyed property-level costs; no invented national average.
    • Warm Homes Plan low-income grant allocations: £4.42bn, 2025–26 to 2029–30 — not committed (programme envelope, not a project award). Programme allocation; an individual home or council scheme is funded only once its award is confirmed.
    Who pays:
    Central government grants; landlords under minimum standards; some households’ own contributions.
    Financing proposed:
    Warm Homes Plan low-income grants; landlord duties.
    Gap remaining:
    Unknown for any scheme until surveyed costs, quality assurance and remediation are priced.
    What delivery needs
    Skills:
    Accredited installers and assessors.
    Operational capacity:
    Council delivery teams.
    Infrastructure:
    None beyond the homes.
    Permissions:
    Landlord and occupant agreement.
    Law:
    Private-rented minimum standards via regulations.
    Public consent:
    Disruption to occupants.
    First step and stages

    First step: Select homes by need and building suitability, then secure the award and installer capacity. (owner: Councils with DESNZ)

    1. Survey — Assessors (proposed stage, not an official timetable)
    2. Install and inspect — Accredited installers; councils (proposed stage, not an official timetable)
    3. Monitor over heating seasons — DESNZ and councils (proposed stage, not an official timetable)

    Depends on: Installer workforce; Quality-assurance regime

    Trade-offs
    Who gains and who loses:
    Gains for low-income households in the least efficient homes; landlords bear costs and may pass some on in rents.
    What else the money or effort could do:
    Grant spent here is not available for other energy or housing programmes.
    Strongest counterargument:
    Savings can be smaller than modelled and poor work can cause damp.
    Risks:
    Poor ventilation, workmanship, rent increases and installer scarcity.
    How we would judge it
    Baseline:
    Fuel poverty rate in England (DESNZ).
    Leading indicator:
    Measures installed, defects found and fixed.
    Outcome:
    Weather-adjusted energy use, indoor conditions, bills and appropriate health outcomes.
    Continue, adapt or stop:
    Scale where measured savings hold after inspection; stop measures that cause defects.
    Earlier option on this page

    This card replaces the option “Insulate and upgrade homes, starting with the least efficient” (funded: Warm Homes Plan: £15bn of public investment over 2025–2030 for up to 5 million homes, including £4.4bn of capital grants for low-income homes. Private rented homes to reach EPC band C by October 2030.). Its evidence: DESNZ’s NEED analysis compares gas use before and after measures with similar homes that had none: for measures installed in 2023, solid wall insulation cut median gas use by 17% in 2024, with smaller savings for cavity wall and loft insulation. DESNZ calls these indicative, mainly from government schemes, and affected by households choosing to heat more once heating is cheaper. DESNZ, National Energy Efficiency Data-Framework (NEED): summary of analysis 2026 (11 June 2026) · DESNZ, Warm Homes Plan (updated 18 March 2026)

    Sources

    Source published March 2026 (Warm Homes Plan); June 2026 (NEED); February 2013 (Cochrane); evidence reviewed 2026-10-04. Reconsider if: Devolved and all-tenure allocations are published; A new UK evaluation of health effects; A new NEED release.

    Also on: Inequality, Hampshire — one shared record, so its cost is counted once.

  • Action 2A17Policy status: external proposal

    Make electricity pricing support cheaper clean heating

    Move remaining levies off electricity onto gas or general taxation, with protection for households who cannot switch, so heat pumps become cheaper to run.

    Budget 2026 bears on this

    Budget 2026 cut VAT on electricity temporarily and removed carbon price support rates, which lowers electricity costs relative to gas.

    Support for Energy BillsCarbon Price Support (CPS)

    Assessment (draft, 6 October review)

    Not assessed in the 6 October review; this action stays in the topic plan with its own evidence.

    Who decides:
    DESNZ and HM Treasury, with Ofgem (Great Britain)
    Evidence:
    Modelled scenario. Distributional modelling on 2025 assumptions; outcomes depend on prices, usage and design.
    Expected effect:
    Direction plausible; size not established.
    Cost and funding

    Not yet costed

    Funding: Not yet costed / funding not identified

    Why it is shortlisted here: Decides whether electric heating is cheaper to run than gas — and who pays for the switch.

    Builds on the option Move policy costs and VAT off bills compared below.

    What it takes
    The problem

    Policy costs recovered mainly through electricity bills make electric heating expensive to run relative to gas.

    Who is affected, and where

    Households in Great Britain, especially those heating with electricity or considering a heat pump. Territory: Great Britain. Northern Ireland has a separate electricity market; not assessed.

    Policy status

    Proposed by researchers or others, not government policy. Partly done: since April 2026, 75% of the domestic Renewables Obligation is funded from taxation for 2026–27 to 2028–29. Further rebalancing onto gas is a Nesta proposal, not government policy.

    The evidence
    What the research found:
    Moving Renewables Obligation and Feed-in Tariff levies to gas: about 8 million households pay less, about 19 million gas households pay about £20 a year more, and a typical switcher to a heat pump saves about £400 a year (all before compensation, on 2025 assumptions).
    Evaluated on:
    Ofgem household archetypes; Great Britain, 2025 prices
    Our recommendation (separate from the research):
    Re-run the distributional modelling on the post-April 2026 baseline by heating type and income before choosing a design.
    Strongest counter-evidence:
    After Budget 2025 policy costs are about a tenth of a typical bill, so further rebalancing has less to move; networks are about a third.
    Effects on record
    • Running cost of switching from a gas boiler to a heat pump: Direction plausible; size not established. modelled, limited confidence; Great Britain. Nesta modelled a saving of about £400 a year for a typical switcher, on 2025 prices before 75% of the Renewables Obligation moved to taxation; not re-run on today’s baseline, so no size is shown.
    • Bills of households that stay on gas: A cost or harm; size not established. modelled, limited confidence; Great Britain. Nesta put the rise at about £76 a year for gas households not eligible for support (about £20 for some 19 million households only if other levies also move to taxation, at about £1.1bn a year), modelled on the April 2025 price cap; households that cannot switch — many tenants — bear it. Corrected 4 Oct 2026 (was “about £20 before compensation”).
    Cost and funding

    Cost completeness: Not yet costed. Funding: Not yet costed / funding not identified.

    • Further levy rebalancing from electricity to gas or taxation (bill transfer; paid by bill-payers, central government): Not yet costed. A transfer between bill-payers (or to taxpayers), not a saving. Must be re-costed on the post-April 2026 baseline, after 75% of the Renewables Obligation moved to taxation.
    • Protection for households who cannot switch from gas (bill transfer; paid by bill-payers): Not yet costed. Nesta’s illustrative design: about £126m a year more for the Warm Home Discount core budget (£514m to £640m) and about £310m a year for a unit-rate discount, both levy-funded, at 2025 assumptions. Not re-modelled on the current baseline, so not shown as a cost.
    Who pays:
    Gas bill-payers or taxpayers, depending on the design; compensation from other bill-payers or a budget.
    Financing proposed:
    A transfer between bill-payers or to taxation — not a saving.
    Gap remaining:
    Not costed on the current baseline.
    What delivery needs
    Skills:
    Heat-pump installers for households to respond.
    Operational capacity:
    Supplier billing changes.
    Infrastructure:
    Network capacity for electrified heat.
    Permissions:
    Ofgem licence changes.
    Law:
    Possibly secondary legislation for levy schemes.
    Public consent:
    Gas households facing higher bills.
    First step and stages

    First step: Rerun distributional modelling for different heating types and incomes under current tariffs. (owner: DESNZ with Ofgem)

    1. Model and consult — DESNZ (proposed stage, not an official timetable)
    2. Legislate where needed — Parliament (proposed stage, not an official timetable)
    3. Phase in with compensation — Ofgem and suppliers (proposed stage, not an official timetable)

    Depends on: Installer capacity (A18); Compensation design

    Trade-offs
    Who gains and who loses:
    Gains for electric-heated and switching households; costs for gas households, many of whom — tenants especially — cannot switch.
    What else the money or effort could do:
    If funded from taxation, it competes with other spending.
    Strongest counterargument:
    Raising gas prices hits households who cannot change their heating.
    Risks:
    Unfair cost-shifting and already-enacted changes double-counted in the baseline.
    How we would judge it
    Baseline:
    Electricity-to-gas unit price ratio in the Ofgem cap.
    Leading indicator:
    Heat-pump installations.
    Outcome:
    Bills at matched consumption by heating type, fuel poverty and clean-heat uptake.
    Continue, adapt or stop:
    Continue if uptake rises without higher fuel poverty among gas households; adapt compensation otherwise.
    Sources

    Source published 5 June 2025 (Nesta); 28 July 2026 (UKERC); evidence reviewed 2026-10-04. Reconsider if: The Renewables Obligation arrangement after 2028–29; A new Ofgem cap methodology; Government response on levy rebalancing.

    Also on: Inflation — one shared record, so its cost is counted once.

  • Action 3A56Policy status: external proposal

    Connect the power Britain needs

    Enforcing the reformed queue’s offer and connection dates, and publishing time to connect, gets ready projects connected sooner; industrial price relief is a separate measure with its own costs.

    Assessment (draft, 6 October review)

    Who decides:
    Ofgem (approves and enforces), the National Energy System Operator and network companies, with DESNZ (Great Britain)
    Evidence:
    Modelled scenario. Only Ofgem’s ex-ante impact assessment exists; no evaluation of the reform’s effect on connection dates or bills has been published.
    Expected effect:
    Direction plausible; size not established.
    Cost and funding

    Not yet costed

    Funding: Not yet costed / funding not identified

    Why it is shortlisted here: The national grid option (Growth list and resilience queue): reform cut the queue, but offers are late and time to connect is not published; enforcing the timetable and reporting it is the bounded change. Industrial price relief is a separate measure, listed with the finding.

    Builds on the option Connect projects to the grid faster compared below.

    What it takes
    The problem

    Connection offers stretched into the 2040s before reform; after it, only 58% of the projects needed for 2030 had offers by June 2026, and Ofgem has twice extended the deadline for the rest, while UK industrial electricity costs far more than in Germany or France.

    Who is affected, and where

    Generation, storage and demand projects in the reformed (Gate 2) connection queue in Great Britain, and the households and firms that pay network costs. Territory: Great Britain. The connections reform covers Great Britain (including Scottish transmission owners); Northern Ireland has its own system operator. The British Industrial Competitiveness Scheme covers Great Britain, with an equivalent scheme funded for Northern Ireland.

    Policy status

    Proposed by researchers or others, not government policy. Baseline: Ofgem approved the connections reform (Gate 2 firm queue) on 15 April 2025; NESO and the networks are issuing offers (Phase 1 deadline extended to 31 October 2026); Great British Grid was announced on 29 September 2026; industrial price relief (BICS) opens from April 2027. Enforcing the timetable and publishing time to connect as a regular measure is a UK Facts proposal, not government policy.

    The evidence
    What the research found:
    Ofgem estimated direct implementation costs under £50m, wasted network works of £220–960m (about £3–£12 per consumer, one-off) and about £5bn of network costs avoided. About 8GW a year connected in the six years to April 2025.
    Evaluated on:
    The pre-reform connection queue; Great Britain, 2025
    Our recommendation (separate from the research):
    Publish offers issued against deadlines and median time to connect each quarter, and use Ofgem’s enforcement powers where network companies miss them.
    Strongest counter-evidence:
    Deadlines have already slipped twice; network reinforcement, not the queue order, may be the binding constraint.
    Cost and funding

    Cost completeness: Not yet costed. Funding: Not yet costed / funding not identified.

      Who pays:
      Electricity bill-payers through network charges; taxpayers for industrial relief (BICS about £600m a year).
      Financing proposed:
      Network allowances set by Ofgem; BICS from energy-system changes and Exchequer money to be scored at the 2026 Budget.
      Gap remaining:
      Unknown: reinforcement capital, its bill impact and Great British Grid’s budget (left to a future spending review).
      What delivery needs
      Skills:
      Network engineers and planners.
      Operational capacity:
      Transmission and distribution construction.
      Infrastructure:
      Network reinforcement.
      Permissions:
      Planning consent for lines and substations (devolved in Scotland and Wales).
      Law:
      None new for enforcement.
      Public consent:
      Local acceptance of new lines.
      First step and stages

      First step: Ofgem requires NESO and network companies to publish offers issued against deadlines and median time to connect for Gate 2 projects each quarter, starting with the 31 October 2026 deadline. (owner: Ofgem with NESO)

      1. Publish offers against deadlines and time to connect — NESO and network companies (proposed stage, not an official timetable)
      2. Enforce missed dates — Ofgem (proposed stage, not an official timetable)
      3. Report capacity connected each year — NESO (proposed stage, not an official timetable)

      Depends on: Network reinforcement; Great British Grid set-up

      Trade-offs
      Who gains and who loses:
      Faster connections help generators, storage and industrial users; network costs are spread across all bill-payers.
      What else the money or effort could do:
      Regulatory attention and network capital diverted from other priorities.
      Strongest counterargument:
      Deadlines without reinforcement may only move delay later.
      Risks:
      Gaming of readiness criteria; bill increases from wasted works.
      How we would judge it
      Baseline:
      June 2026: 713 of 1,223 pre-2030 projects (58%, 37GW) had offers; about 8GW a year connected in the six years to April 2025.
      Leading indicator:
      Offers issued against the 31 October 2026 and 31 January 2027 deadlines.
      Outcome:
      Capacity connected each year and median time to connect.
      Continue, adapt or stop:
      Tighten enforcement where deadlines slip without a network constraint.
      Sources

      Source published 15 April 2025 (Ofgem); 10 June 2026 (NESO); 2 October 2026 (Ofgem); evidence reviewed 2026-10-07. Reconsider if: The Gate 2 Phase 1 deadline (31 October 2026); Great British Grid’s establishment; The Budget on 28 October 2026.

    How the options are assessed

    One shared record per option — the same one the national plan reads. Delivery risk, gate and list membership are separate judgements.

    • Connect the power Britain needs — Red delivery RAG; gate pending
    • Warm homes, inspected before payment — Amber delivery RAG; gate pending
    • Change how utilities fund investment and share the risks — Red delivery RAG; gate pending

    Provisional single-reviewer assessments from the 6 October 2026 review; not approved business cases, and not government policy.

    • A56Delivery risk: RedGate: pending

      Connect the power Britain needs

      Existing action A56, assessed at the same scope.

      Provisional single-reviewer assessment; not an approved business case.

      Who and where
      Generation, storage and demand projects in the reformed (Gate 2) connection queue in Great Britain, and the households and firms that pay network costs. (from the action record) Jurisdiction: Great Britain.
      Result so far
      Range if completed: 13.0–19.0 out of 30 (equal weights; not yet assessed: expected incremental benefit (Bn), incremental affordability (Co))
      Funded now (baseline)
      Baseline: Ofgem approved the connections reform (Gate 2 firm queue) on 15 April 2025; NESO and the networks are issuing offers (Phase 1 deadline extended to 31 October 2026); Great British Grid was announced on 29 September 2026; industrial price relief (BICS) opens from April 2027. Enforcing the timetable and publishing time to connect as a regular measure is a UK Facts proposal, not government policy. (from the action record)
      The change assessed (marginal)
      Marginal change not yet defined
      What the evidence supports—and the next decision

      Connection reform, new network assets and industrial bill relief operate through different mechanisms and timescales.

      AI-assisted analytical follow-up · 8 October 2026. Proposed appraisal design; the attributed scores below are unchanged. No funding or delivery agreement is implied.

      Define the change
      Separate a connection bottleneck from an industrial-price support scheme. For each, name eligible users, the existing settlement and the additional change.
      Test whether it works
      Energised capacity and usable connection dates for networks; additional viable production and energy efficiency for relief. Queue removals alone are not delivered capacity.
      Establish the cost
      Network capital, operations and financing plus any time-limited subsidy. Show incidence on taxpayers and other bill-payers and test expiry of support.
      Protect against harm
      Avoid subsidy commitments that depend on speculative future receipts or crowd out essential connections.

      Read with the outcome evidence and sources in the full assessment. Monitoring proposals are not existing baseline measurements. A numerical benefit or cost score needs evidence for the defined increment, not just the scale of the problem.

      Full assessment of Connect the power Britain needs: ten criteria, scenarios, delivery, costs and monitoring
      The ten criteria (0–3)

      Each criterion is scored 0 to 3 by the reviewer. “Not yet assessed” means unknown: it is never counted as zero.

      1. Scale and severity (Sc)3 of 3 — Severe harm across a broad population

        Reviewer’s reason: Provisional problem-importance judgement from linked site pages; not the scale of achievable benefit.

      2. Increment beyond baseline (Ad)2 of 3 — Specific material change to existing delivery

        Reviewer’s reason: Separate queue management, network reinforcement and industrial levies; identify projects, kit, engineers and regulator decisions. A missing rating requires a defined marginal change.

      3. Confidence in the proposed action (Ev)1 of 3 — Indirect, mixed, modelled or weak causal support

        Reviewer’s reason: Engineering need and queue evidence exist; the marginal effects of queue reform and industrial bill relief are different questions.

      4. Expected incremental benefit (Bn)Not yet assessed

        Reviewer’s reason: Unknown unless a reasonably defined target-population benefit can be judged; no bonus merely for spanning domains.

      5. Residual harms (Hm)1 of 3 — Material harm/unresolved mitigation

        Reviewer’s reason: Binding specialist/kit constraints; moving charges to households; stranded assets.

      6. Incremental affordability (Co)Not yet assessed

        Reviewer’s reason: Capital and operating network costs, financing, bill incidence, relief duration and funding.

      7. Delivery capacity (Ca)1 of 3 — Binding scarce resource

        Reviewer’s reason: Separate queue management, network reinforcement and industrial levies; identify projects, kit, engineers and regulator decisions.

      8. Distribution (Fa)2 of 3 — Mixed or broadly neutral with safeguards

        Reviewer’s reason: Provisional distribution judgement for the stated target; verify who pays, who gains and excluded groups.

      9. Meaningful first outcome (Ti)1 of 3 — More than three but less than ten years

        Reviewer’s reason: First meaningful outcome, not announcement: Time to energisation, reliability and industrial costs; household bill impacts.

      10. Readiness (Rd)2 of 3 — Named commissioning/allocation/coordination step

        Reviewer’s reason: Energy departments, system/network operators and regulators; Split infrastructure and bill-policy appraisal

      Four weightings

      Normalised as 10 × weighted sum ÷ sum of weights, on a 0–30 scale. Where a criterion is not yet assessed, the range is the lowest and highest result if it were later scored 0 or 3 — not a score, a confidence interval or a rank.

      • Equal weights: Range if completed: 13.0–19.0 out of 30. Not yet assessed: expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.
      • Evidence doubled: Range if completed: 12.7–18.2 out of 30. Not yet assessed: expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.
      • Scale doubled: Range if completed: 14.5–20.0 out of 30. Not yet assessed: expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.
      • Cost ignored (the funding gate still applies): Range if completed: 14.4–17.8 out of 30. Not yet assessed: expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.

      Funding gate: Not passed — the cost is not yet assessed or no allocation is committed for this scope. Ignoring cost in a weighting never removes the gate.

      Delivery risk and gate

      Delivery risk shown: RedReview’s claim: Red. Best the recorded evidence allows: Red.

      Review’s reason: Binding specialist/kit constraints; moving charges to households; stranded assets.

      Why it is not Green yet

      • Delivery obstacle: Binding specialist/kit constraints; moving charges to households; stranded assets..
      • Scope (population, place and increment) not verified against the delivery baseline.
      • No verified owner with the powers in place.
      • Delivery capacity not verified.
      • Lifetime incremental costs not complete.
      • No credible funding (a committed allocation for the scope).
      • Safeguards not specified.
      • Monitoring lacks a metric, a data source or a baseline.

      Green needs verified scope, a verified owner with the powers, verified capacity, complete lifetime costs with credible funding, specified safeguards and monitoring with a metric, source and baseline. Amber means appraisal gaps remain; Red means a material delivery obstacle. Red does not mean unimportant.

      Gate: Pending — appraisal incomplete (review label: “Pending: incomplete appraisal”).

      Why: Scores incomplete; Funding gate not passed (cost unknown or no credible funding).

      The gate is separate from national list membership: being listed does not make an option eligible, and an eligible option need not be listed.

      Cost and funding

      Lifetime costing: Not established. Review: “Full incremental costing not established in reviewed material”.

      Still to cost: Capital and operating network costs, financing, bill incidence, relief duration and funding.

      Funding status: not identified.

      Owner, powers and capacity

      Proposed owner: Energy departments, system/network operators and regulators (proposed, unverified).

      Powers: needs a decision or allocation. Capacity: binding constraint.

      Powers and capacity read from the review’s Rd and Ca anchors; no proposed owner has agreed to act (the review: “Proposed owners have not agreed to act”).

      England:
      Ofgem (approves and enforces), the National Energy System Operator and network companies, with DESNZ (action record)
      Scotland:
      Ofgem (approves and enforces), the National Energy System Operator and network companies, with DESNZ (action record)
      Wales:
      Ofgem (approves and enforces), the National Energy System Operator and network companies, with DESNZ (action record)
      Northern Ireland:
      not assessed

      The connections reform covers Great Britain (including Scottish transmission owners); Northern Ireland has its own system operator. The British Industrial Competitiveness Scheme covers Great Britain, with an equivalent scheme funded for Northern Ireland.

      Dependencies, safeguards and risks

      Depends on: None recorded.

      Safeguards

      None specified yet.

      Risks and residual harms: Binding specialist/kit constraints; moving charges to households; stranded assets.

      Monitoring and measured results

      Metric: Time to energisation, reliability and industrial costs; household bill impacts.

      Data source: Not yet named. Baseline: Not yet established.

      Measures already on the domain page

      A page measure is not necessarily the review’s metric; linking the two is an editorial decision still to be made.

      Evidence for the outcome

      Outcome: Time to energisation, reliability and industrial costs; household bill impacts.

      Engineering need and queue evidence exist; the marginal effects of queue reform and industrial bill relief are different questions.

      Review record

      Assessment status: Provisional single-reviewer assessment; not an approved business case.

      Reviewer: Original assessment author (name not supplied). Reviewed: 6 October 2026.

      Scored in the working review of 6 October 2026 on the shared ten-criterion scale (one reviewer); not independently calibrated.

      First 90 days (review): Produce a signed scope and current-delivery baseline; Separate queue management, network reinforcement and industrial levies; identify projects, kit, engineers and regulator decisions. Obtain incremental costs and an accountable decision before expansion.

      Decision route: Split infrastructure and bill-policy appraisal

      An editorial screening framework by one reviewer, not a formal appraisal or business case. Proposed owners have not agreed to act.

    • A18Delivery risk: AmberGate: pending

      Warm homes, inspected before payment

      Existing action A18, assessed at the same scope.

      Provisional single-reviewer assessment; not an approved business case.

      Who and where
      Low-income and fuel-poor households in inefficient homes, in England. (from the action record) Jurisdiction: England.
      Result so far
      Range if completed: 17.0–20.0 out of 30 (equal weights; not yet assessed: incremental affordability (Co))
      Funded now (baseline)
      The Warm Homes Plan allocates £4,422m of low-income home grants for 2025–26 to 2029–30. The proposal here is targeting by need plus quality assurance, within that programme. (from the action record)
      The change assessed (marginal)
      Health-linked selection, independent inspection before payment and an evaluation inside the Warm Homes grants. (from the superseded 4 October selection table)
      What the evidence supports—and the next decision

      Insulation can reduce energy need, but poor installation can cause damp and costly remediation. Quality control is part of the intervention.

      AI-assisted analytical follow-up · 8 October 2026. Proposed appraisal design; the attributed scores below are unchanged. No funding or delivery agreement is implied.

      Define the change
      Select homes using health and building-condition criteria; compare independently inspected upgrades with the funded baseline.
      Test whether it works
      Weather-adjusted energy use, comfort, damp, health and defects; measure rebound and follow homes beyond installation.
      Establish the cost
      Assessment, works, ventilation, inspection, remediation, maintenance and administration. Do not count grants as both a cost and a resource saving.
      Protect against harm
      Require whole-building suitability, tenant protection and enforceable defect repair before payment.

      Read with the outcome evidence and sources in the full assessment. Monitoring proposals are not existing baseline measurements. A numerical benefit or cost score needs evidence for the defined increment, not just the scale of the problem.

      Full assessment of Warm homes, inspected before payment: ten criteria, scenarios, delivery, costs and monitoring
      The ten criteria (0–3)

      Each criterion is scored 0 to 3 by the reviewer. “Not yet assessed” means unknown: it is never counted as zero.

      1. Scale and severity (Sc)3 of 3 — Severe harm across a broad population

        Reviewer’s reason: Provisional problem-importance judgement from linked site pages; not the scale of achievable benefit.

      2. Increment beyond baseline (Ad)2 of 3 — Specific material change to existing delivery

        Reviewer’s reason: Target poor-quality homes; survey suitability/ventilation; use qualified installers and independent inspection; establish redress. A missing rating requires a defined marginal change.

      3. Confidence in the proposed action (Ev)1 of 3 — Indirect, mixed, modelled or weak causal support

        Reviewer’s reason: Energy-saving evidence does not evaluate inspection-before-payment or prove health outcomes for this package.

      4. Expected incremental benefit (Bn)2 of 3 — Material for the target population

        Reviewer’s reason: Unknown unless a reasonably defined target-population benefit can be judged; no bonus merely for spanning domains.

        Reason and score disagree — under review

      5. Residual harms (Hm)1 of 3 — Material harm/unresolved mitigation

        Reviewer’s reason: Damp, overheating, defects and installer constraints; inspection is not a guarantee.

      6. Incremental affordability (Co)Not yet assessed

        Reviewer’s reason: Works, assessment, inspection, maintenance, remediation and administration against existing grants.

      7. Delivery capacity (Ca)1 of 3 — Binding scarce resource

        Reviewer’s reason: Target poor-quality homes; survey suitability/ventilation; use qualified installers and independent inspection; establish redress.

      8. Distribution (Fa)3 of 3 — Benefits concentrated on disadvantaged people with assessed burdens

        Reviewer’s reason: Provisional distribution judgement for the stated target; verify who pays, who gains and excluded groups.

      9. Meaningful first outcome (Ti)2 of 3 — More than one and up to three years

        Reviewer’s reason: First meaningful outcome, not announcement: Measured energy use, comfort, health and defects; household costs.

      10. Readiness (Rd)2 of 3 — Named commissioning/allocation/coordination step

        Reviewer’s reason: Energy/housing departments, councils and installers; Quality-assured targeted delivery

      Four weightings

      Normalised as 10 × weighted sum ÷ sum of weights, on a 0–30 scale. Where a criterion is not yet assessed, the range is the lowest and highest result if it were later scored 0 or 3 — not a score, a confidence interval or a rank.

      • Equal weights: Range if completed: 17.0–20.0 out of 30. Not yet assessed: incremental affordability (Co). Funding gate: not passed.
      • Evidence doubled: Range if completed: 16.4–19.1 out of 30. Not yet assessed: incremental affordability (Co). Funding gate: not passed.
      • Scale doubled: Range if completed: 18.2–20.9 out of 30. Not yet assessed: incremental affordability (Co). Funding gate: not passed.
      • Cost ignored (the funding gate still applies): Range if completed: 18.9–18.9 out of 30. Not yet assessed: incremental affordability (Co). The missing criteria carry no weight here, so the ends meet; the record is still incomplete. Funding gate: not passed.

      Funding gate: Not passed — the cost is not yet assessed or no allocation is committed for this scope. Ignoring cost in a weighting never removes the gate.

      Delivery risk and gate

      Delivery risk shown: AmberReview’s claim: Amber. Best the recorded evidence allows: Amber.

      Review’s reason: Works, assessment, inspection, maintenance, remediation and administration against existing grants.

      Why it is not Green yet

      • Scope (population, place and increment) not verified against the delivery baseline.
      • No verified owner with the powers in place.
      • Delivery capacity not verified.
      • Lifetime incremental costs not complete.
      • No credible funding (a committed allocation for the scope).
      • Safeguards not specified.
      • Monitoring lacks a metric, a data source or a baseline.

      Green needs verified scope, a verified owner with the powers, verified capacity, complete lifetime costs with credible funding, specified safeguards and monitoring with a metric, source and baseline. Amber means appraisal gaps remain; Red means a material delivery obstacle. Red does not mean unimportant.

      Gate: Pending — appraisal incomplete (review label: “Pending: incomplete appraisal”).

      Why: Scores incomplete; Funding gate not passed (cost unknown or no credible funding).

      The gate is separate from national list membership: being listed does not make an option eligible, and an eligible option need not be listed.

      Cost and funding

      Lifetime costing: Partial — some lines costed, no whole-life total. Review: “Full incremental costing not established in reviewed material”.

      • Warm Homes Plan: low-income home grants (published programme envelope; C-WHP-LOWINCOME)
      • Property surveys, installation quality checks, remediation and monitoring (not costed; C-A18-QUALITY)

      Still to cost: Works, assessment, inspection, maintenance, remediation and administration against existing grants.

      Funding status: programme route, not allocated.

      Owner, powers and capacity

      Proposed owner: Energy/housing departments, councils and installers (proposed, unverified).

      Powers: needs a decision or allocation. Capacity: binding constraint.

      Powers and capacity read from the review’s Rd and Ca anchors; no proposed owner has agreed to act (the review: “Proposed owners have not agreed to act”).

      England:
      DESNZ and MHCLG, with councils, landlords and accredited installers (action record)
      Scotland:
      not assessed
      Wales:
      not assessed
      Northern Ireland:
      not assessed

      Warm Homes Plan grants are England-focused; devolved arrangements were to be set out separately; Scotland and Wales run their own schemes.

      Dependencies, safeguards and risks

      Depends on: None recorded.

      Safeguards

      None specified yet.

      Risks and residual harms: Damp, overheating, defects and installer constraints; inspection is not a guarantee.

      Monitoring and measured results

      Metric: Measured energy use, comfort, health and defects; household costs.

      Data source: Not yet named. Baseline: Not yet established.

      Measures already on the domain page

      A page measure is not necessarily the review’s metric; linking the two is an editorial decision still to be made.

      Evidence for the outcome

      Outcome: Measured energy use, comfort, health and defects; household costs.

      Energy-saving evidence does not evaluate inspection-before-payment or prove health outcomes for this package.

      Effect records for this action

      • Gas use in homes after solid wall insulation: −17% median gas use (evaluated, moderate confidence; England and Wales)
      • General, respiratory and mental health of residents: size not established (evaluated, limited confidence; Studies in several countries, searched to 2012)
      • Low-income households counted as fuel poor: size not established (plausible spillover, limited confidence; England)
      • Damp and mould after poorly specified or installed insulation: size not established (plausible spillover, limited confidence; England)
      Review record

      Assessment status: Provisional single-reviewer assessment; not an approved business case.

      Reviewer: Original assessment author (name not supplied). Reviewed: 6 October 2026.

      Scored in the working review of 6 October 2026 on the shared ten-criterion scale (one reviewer); not independently calibrated.

      First 90 days (review): Produce a signed scope and current-delivery baseline; Target poor-quality homes; survey suitability/ventilation; use qualified installers and independent inspection; establish redress. Obtain incremental costs and an accountable decision before expansion.

      Decision route: Quality-assured targeted delivery

      An earlier assessment exists on the 4 October 2026 selection table (nine H/M/L bands; superseded 7 October 2026). Its bands are kept, not converted into these scores.

      An editorial screening framework by one reviewer, not a formal appraisal or business case. Proposed owners have not agreed to act.

    • A64Delivery risk: RedGate: pending

      Change how utilities fund investment and share the risks

      Proposed new action A64; sourced research home and appraisal design; scope and funding remain provisional.

      Provisional single-reviewer assessment; not an approved business case.

      Who and where
      Population not yet defined. Jurisdiction: not defined.
      Result so far
      Range if completed: 9.0–18.0 out of 30 (equal weights; not yet assessed: increment beyond baseline (Ad), expected incremental benefit (Bn), incremental affordability (Co))
      Funded now (baseline)
      Funded baseline not yet stated
      The change assessed (marginal)
      Marginal change not yet defined
      What the evidence supports—and the next decision

      A lower financing rate is only one part of utility value. Acquisition terms, investment needs and risk transfer can reverse the result.

      AI-assisted analytical follow-up · 8 October 2026. Proposed appraisal design; the attributed scores below are unchanged. No funding or delivery agreement is implied.

      Define the change
      Compare regulation, restructuring and acquisition for a specified network against its current settlement and service obligations.
      Test whether it works
      Reliability, investment delivery, environmental performance and total bills; stress finance costs, purchase premium and asset-condition uncertainty.
      Establish the cost
      Acquisition, debt, capital renewal, operations and contingent liabilities. Keep financing transfers distinct from real efficiency gains.
      Protect against harm
      Preserve service continuity and consumer protection; do not present one spreadsheet scenario as an observed saving.

      Read with the outcome evidence and sources in the full assessment. Monitoring proposals are not existing baseline measurements. A numerical benefit or cost score needs evidence for the defined increment, not just the scale of the problem.

      Full assessment of Change how utilities fund investment and share the risks: ten criteria, scenarios, delivery, costs and monitoring
      The ten criteria (0–3)

      Each criterion is scored 0 to 3 by the reviewer. “Not yet assessed” means unknown: it is never counted as zero.

      1. Scale and severity (Sc)2 of 3 — Serious harm to a defined group or widespread moderate harm

        Reviewer’s reason: Provisional problem-importance judgement from linked site pages; not the scale of achievable benefit.

      2. Increment beyond baseline (Ad)Not yet assessed

        Reviewer’s reason: Separate sectors and instruments; assess legal/regulatory powers, financing, compensation, investment and service quality. A missing rating requires a defined marginal change.

      3. Confidence in the proposed action (Ev)1 of 3 — Indirect, mixed, modelled or weak causal support

        Reviewer’s reason: Site scenarios are not demonstrated savings. Price controls, insolvency, refinancing and asset ownership have different counterfactuals.

      4. Expected incremental benefit (Bn)Not yet assessed

        Reviewer’s reason: Unknown unless a reasonably defined target-population benefit can be judged; no bonus merely for spanning domains.

      5. Residual harms (Hm)1 of 3 — Material harm/unresolved mitigation

        Reviewer’s reason: Underinvestment, legal disputes and transferred taxpayer risk; no additive headline saving.

      6. Incremental affordability (Co)Not yet assessed

        Reviewer’s reason: Acquisition/compensation, debt, financing, capital maintenance, contingent liabilities and consumer bills under each option.

      7. Delivery capacity (Ca)1 of 3 — Binding scarce resource

        Reviewer’s reason: Separate sectors and instruments; assess legal/regulatory powers, financing, compensation, investment and service quality.

      8. Distribution (Fa)2 of 3 — Mixed or broadly neutral with safeguards

        Reviewer’s reason: Provisional distribution judgement for the stated target; verify who pays, who gains and excluded groups.

      9. Meaningful first outcome (Ti)1 of 3 — More than three but less than ten years

        Reviewer’s reason: First meaningful outcome, not announcement: Whole-life customer costs, reliability, investment and taxpayer exposure.

      10. Readiness (Rd)1 of 3 — Legislation/external agreement or major enabling work

        Reviewer’s reason: Sector regulators, Treasury, relevant departments and infrastructure bodies; Split regulatory and ownership options

      Four weightings

      Normalised as 10 × weighted sum ÷ sum of weights, on a 0–30 scale. Where a criterion is not yet assessed, the range is the lowest and highest result if it were later scored 0 or 3 — not a score, a confidence interval or a rank.

      • Equal weights: Range if completed: 9.0–18.0 out of 30. Not yet assessed: increment beyond baseline (Ad), expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.
      • Evidence doubled: Range if completed: 9.1–17.3 out of 30. Not yet assessed: increment beyond baseline (Ad), expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.
      • Scale doubled: Range if completed: 10.0–18.2 out of 30. Not yet assessed: increment beyond baseline (Ad), expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.
      • Cost ignored (the funding gate still applies): Range if completed: 10.0–16.7 out of 30. Not yet assessed: increment beyond baseline (Ad), expected incremental benefit (Bn), incremental affordability (Co). Funding gate: not passed.

      Funding gate: Not passed — the cost is not yet assessed or no allocation is committed for this scope. Ignoring cost in a weighting never removes the gate.

      Delivery risk and gate

      Delivery risk shown: RedReview’s claim: Red. Best the recorded evidence allows: Red.

      Review’s reason: Underinvestment, legal disputes and transferred taxpayer risk; no additive headline saving.

      Why it is not Green yet

      • Delivery obstacle: Underinvestment, legal disputes and transferred taxpayer risk; no additive headline saving..
      • Scope (population, place and increment) not verified against the delivery baseline.
      • No verified owner with the powers in place.
      • Delivery capacity not verified.
      • Lifetime incremental costs not complete.
      • No credible funding (a committed allocation for the scope).
      • Safeguards not specified.
      • Monitoring lacks a metric, a data source or a baseline.

      Green needs verified scope, a verified owner with the powers, verified capacity, complete lifetime costs with credible funding, specified safeguards and monitoring with a metric, source and baseline. Amber means appraisal gaps remain; Red means a material delivery obstacle. Red does not mean unimportant.

      Gate: Pending — appraisal incomplete (review label: “Pending: incomplete appraisal”).

      Why: Scores incomplete; Funding gate not passed (cost unknown or no credible funding).

      The gate is separate from national list membership: being listed does not make an option eligible, and an eligible option need not be listed.

      Cost and funding

      Lifetime costing: Not established. Review: “Full incremental costing not established in reviewed material”.

      Still to cost: Acquisition/compensation, debt, financing, capital maintenance, contingent liabilities and consumer bills under each option.

      Funding status: not established in review.

      Owner, powers and capacity

      Proposed owner: Sector regulators, Treasury, relevant departments and infrastructure bodies (proposed, unverified).

      Powers: needs legislation or external agreement. Capacity: binding constraint.

      Powers and capacity read from the review’s Rd and Ca anchors; no proposed owner has agreed to act (the review: “Proposed owners have not agreed to act”).

      England:
      not assessed
      Scotland:
      not assessed
      Wales:
      not assessed
      Northern Ireland:
      not assessed

      Not defined in the review.

      Dependencies, safeguards and risks

      Depends on: None recorded.

      Safeguards

      None specified yet.

      Risks and residual harms: Underinvestment, legal disputes and transferred taxpayer risk; no additive headline saving.

      Monitoring and measured results

      Metric: Whole-life customer costs, reliability, investment and taxpayer exposure.

      Data source: Not yet named. Baseline: Not yet established.

      Evidence for the outcome

      Outcome: Whole-life customer costs, reliability, investment and taxpayer exposure.

      Site scenarios are not demonstrated savings. Price controls, insolvency, refinancing and asset ownership have different counterfactuals.

      Review record

      Assessment status: Provisional single-reviewer assessment; not an approved business case.

      Reviewer: Original assessment author (name not supplied). Reviewed: 6 October 2026.

      Scored in the working review of 6 October 2026 on the shared ten-criterion scale (one reviewer); not independently calibrated.

      First 90 days (review): Produce a signed scope and current-delivery baseline; Separate sectors and instruments; assess legal/regulatory powers, financing, compensation, investment and service quality. Obtain incremental costs and an accountable decision before expansion.

      Decision route: Split regulatory and ownership options

      An editorial screening framework by one reviewer, not a formal appraisal or business case. Proposed owners have not agreed to act.

    Decision brief

    • Fix the coldest homes first — and measure bills and health separately

    The leading option set out as a decision someone could take: who decides, who benefits, the best evidence, cost and funding, and the main trade-off. The full research record is one click away.

    Decision briefExisting programmeReviewed 2026-10-04

    Fix the coldest homes first — and measure bills and health separately

    Decision required
    Whether DESNZ adds independent inspection before final payment to the low-income grant rules, and councils with health partners agree referral routes so homes are chosen by health need as well as income.
    Who and where
    Low-income households in homes rated EPC D to G, prioritising those with health conditions made worse by cold. Applies in: England.
    Accountable body
    Department for Energy Security and Net Zero
    Intervention
    Survey, then install insulation, heating and ventilation together in the coldest homes chosen by need, and inspect before final payment.
    Best evidence, and where it applies
    Solid wall insulation cut median gas use by 17% (England and Wales); a New Zealand randomised trial found insulation halved the odds of poor self-rated health in homes with respiratory illness.Studied in: Homes in England and Wales with measures installed, mostly under government schemes (2024 savings for measures installed in 2023).How closely the comparison transfers to this decision: Seven low-income communities, New Zealand — partial.
    Extra cost of this change
    Capital: Warm Homes low-income grants — £4.42bn in total, 2025–26 to 2029–30, price basis not stated by the source; Energy performance upgrades per home (average cap) — £16,600 per home (average across a project).Recurring: Administration and ancillary costs — Up to 15% of total project spend; Surveys, independent inspection, remediation and monitoring — Not yet costed.One-off or mixed: Linked health and energy evaluation — not yet established.
    Funding
    Not funded yet: a possible funding route exists, but nothing is allocated to this change.Committed to this change: none.Possible source, not an award: Warm Homes Plan low-income grant allocations (£4.42bn).Unfunded: Inspection, remediation and evaluation costs are not established; the £4.4bn is a programme envelope, not an award to this change.
    Savings and wider benefits
    Not yet specified: no cashable saving or avoided cost has been costed for this change. Expected outcomes are listed one by one in the research appendix and are never added together or counted as money available.
    First 90-day step
    Inspection and remediation standard in scheme rules; first health-referred homes surveyed.The proposed first milestone; a 90-day date is not yet specified. Owner: DESNZ with councils. Proposed by UK Facts, not an official deadline.
    Twelve-month milestone
    Not yet specified.Time to a first useful result: Warmth and energy use after one heating season; health outcomes after two.
    Outcome, and when to scale or stop
    Measure: Inspections passed first time and defects remedied.Scale if: Measured savings and warmth hold after inspection.Stop if: A measure causes defects; stop that measure.
    Main trade-off
    Installers and grant money spent here are not available for other work, and poor installation can cause damp.

    An editorial proposal by UK Facts for discussion, not government policy. Records: A18 · effects E-A18-GAS-USE, E-A18-HEALTH, E-A18-DAMP · costs C-WHP-LOWINCOME, C-A18-QUALITY

    Research appendix: study design, effect sizes and limits, alternatives, full costing, international comparisons and how we would know

    1.The change, in plain words

    Fix the coldest homes first — and measure bills and health separately

    2.The decision requested

    Decision
    Add independent post-installation inspection, with retained final payment and a remediation route, to Warm Homes grant rules; in a first set of councils, select eligible homes through GP or respiratory-service referral and evaluate warmth, energy use, bills and health separately against a comparison.
    Accountable institution
    Department for Energy Security and Net Zero
    Geography
    England
    Powers
    Existing scheme rules and grant conditions; no new law.
    Delivery partners
    Councils and Warm Homes: Local Grant consortia; NHS primary care and respiratory services; Retrofit coordinators, TrustMark installers and independent inspectors; Landlords

    3.Who it is for, and what changes beyond today

    Target population
    Low-income households in homes rated EPC D to G, prioritising those with health conditions made worse by cold.
    Eligibility
    Warm Homes: Local Grant eligibility (for example gross household income of £36,000 or less), plus health referral for priority.
    Scale
    Set from local need, installer capacity and a costed business case; WH:LG has allocated funding to 74 projects involving 271 councils.
    Baseline
    About 9.4% of households in England were fuel poor in 2025. Under WH:LG, about 1,980 households were reported upgraded by the end of April 2026 (provisional; DESNZ says this undercounts).

    Source: Department for Energy Security and Net Zero, Annual Fuel Poverty Statistics in England, 2026 (2025 data) (Report p.1); Department for Energy Security and Net Zero, Warm Homes: Local Grant statistics – May 2026 (Key statistics)

    Change beyond existing law or funding
    Scheme rules already require PAS 2035 and TrustMark installers; the change adds health-linked selection, independent inspection before final payment, a remediation route and an evaluation that measures health separately.

    4.How it would work

    Do: Survey, then install insulation, heating and ventilation together in the coldest homes chosen by need, and inspect before final payment. Changing: Warmer, drier homes that need less energy to heat.

    • Gas use after solid wall insulation

      Measured for this interventionEffect record E-A18-GAS-USE

      Median −17% in England and Wales (observational, indicative).

    • Residents’ health

      Hypothesis to testEffect record E-A18-HEALTH

      Measured in New Zealand homes for a population chosen for respiratory illness; a hypothesis for English homes until evaluated.

    • Damp and mould after poor installation

      Hypothesis to testEffect record E-A18-DAMP

      A risk the inspection is meant to catch; no national defect rate is published.

    Outcomes are kept separate and never added into one impact figure.

    5.Best evidence

    • National Energy Efficiency Data-Framework (NEED): summary of analysis 2026

      Author or institution:
      Department for Energy Security and Net Zero
      Published:
      June 2026
      Evaluation period:
      2024 savings for measures installed in 2023
      Design:
      Observational comparison of metered gas use in homes with and without measures
      Sample or population:
      Homes in England and Wales with measures installed, mostly under government schemes
      Effect and uncertainty:
      Median gas saving 17% after solid wall insulation; indicative and varies between years
      Limits:
      Not randomised; includes households choosing to heat more

      Where: Section 3, Figure 3.1. Affiliation is provenance, not proof of quality.

    • Effect of insulating existing houses on health inequality: cluster randomised study in the community

      Author or institution:
      Howden-Chapman P et al. (University of Otago)
      Published:
      March 2007
      Evaluation period:
      Winters of 2001 and 2002
      Design:
      Cluster randomised, single-blinded
      Sample or population:
      1,350 low-income New Zealand households with a member with respiratory symptoms
      Effect and uncertainty:
      Fair/poor self-rated health OR 0.50 (0.38 to 0.68); GP visits 0.73 (0.62 to 0.87); respiratory admissions 0.53 (0.22 to 1.29), not significant
      Limits:
      Different housing stock and climate; self-reported outcomes

      Where: Abstract; Methods. Affiliation is provenance, not proof of quality.

    6.Alternatives, counter-evidence and who loses

    Closest feasible alternative
    Rebalancing electricity and gas prices to favour clean heating (A17): cheaper for government but modelled on an overtaken baseline and raises bills for households that cannot switch.
    Strongest counter-evidence
    The Cochrane review found health improvements only “possible”, clearest where warmth was inadequate; savings vary year to year.

    Source: Cochrane / Hilary Thomson and colleagues, Housing improvements for health and associated socio-economic outcomes (Cochrane Review CD008657); plain-language title 'Housing improvement as an investment to improve health' (Abstract: main results and authors’ conclusions); Department for Energy Security and Net Zero, National Energy Efficiency Data-Framework (NEED): summary of analysis 2026 (Section 3)

    Distributional effects
    Gains for low-income households in the least efficient homes; private landlords contribute after the first home and may pass costs on in rents.
    Main downside
    Scarce installers diverted from other work, and damp if work is poor — which is why inspection comes before payment.

    The options compared, including current policy

    • The proposal

      Health-linked selection, inspection before payment, separate measures

      Who is reached
      Low-income households in the coldest homes with health needs
      Evidence
      Observational energy savings; NZ RCT for health
      Likely outcome and timing
      Warmer homes and lower use in a heating season; health a hypothesis
      Cost and funding
      Within the grant; inspection and evaluation not costed
      Main trade-off
      Installer capacity; fewer homes if inspection costs more
    • Current policy

      Current policy: Warm Homes grants as run

      Who is reached
      Low-income households in EPC D–G homes
      Evidence
      PAS 2035 standards; no linked evaluation
      Likely outcome and timing
      Energy savings; health unmeasured
      Cost and funding
      £4.4bn envelope to 2029–30
      Main trade-off
      No health targeting or independent check before payment
    • Alternative

      Rebalance energy prices instead

      Who is reached
      Electricity-heated households
      Evidence
      Modelled on an overtaken baseline
      Likely outcome and timing
      Lower electricity bills
      Cost and funding
      Bill or tax transfer
      Main trade-off
      Higher gas bills for those who cannot switch

    7.What other countries or the devolved nations show

    Country lesson · Seven low-income communities, New Zealand, Winters of 2001 and 2002

    Insulating cold, damp homes in New Zealand

    Evidence: Experimental or quasi-experimental evaluationPartial match: some conditions differ

    What was changed
    A free, standard retrofit package to government specification — ceiling insulation, draught stopping round windows and doors, insulating paper under floors and a polythene moisture barrier on the ground — installed by trained community teams.
    Study design and population
    Community-based cluster randomised study, single-blinded (inspectors and interviewers did not know which homes were insulated). 1,350 uninsulated households (4,407 people) where at least one member had respiratory symptoms; two thirds in the three most deprived tenths of areas.
    Measured outcome there
    Warmer, drier homes (bedrooms +0.5°C; humidity −2.3%) while using 81% of the energy of uninsulated homes. Odds of fair or poor self-rated health halved (OR 0.50, 0.38 to 0.68); fewer children off school (0.49) and adults off work (0.62); fewer GP visits (0.73).
    Cost status
    Historic only: about £700 a house excluding taxes at 2001 prices — not a guide to current English costs.
    What failed or remains uncertain
    Respiratory hospital admissions fell but not significantly (OR 0.53, 0.22 to 1.29); most outcomes were self-reported by occupants who knew their homes were insulated; temperature gains were small and partly taken as lower energy use.
    Why the UK differs
    English stock is largely brick and solid-wall, much already has loft insulation, and the climate is colder; English schemes treat whole homes under PAS 2035 at much higher cost. The trial chose households with respiratory illness, so health gains for a general fuel-poor population are less certain.
    First change required here
    Select homes by health need as well as income and energy rating — for example through GP or respiratory-service referral — and measure warmth, energy use, bills and health separately against a comparison group.

    Not a UK forecast: the effect above was measured in that place and population. Source: BMJ, Effect of insulating existing houses on health inequality: cluster randomised study in the community (Abstract; Methods; Discussion). Reviewed 2026-10-04.

    8.What delivery needs first

    • staff — TrustMark installers, retrofit coordinators and independent inspectors. (Scarce resource shared with other priorities; owner: DESNZ, accreditation bodies and Skills England)
    • data — A health referral route and consent to link health outcomes for the evaluation. (Requirement; owner: Councils with integrated care boards)
    • dependency — Installer demand sequenced with housebuilding and infrastructure (NP5). (Scarce resource shared with other priorities; owner: NISTA with DESNZ)

    9.What it would cost

    How the cost is built up: Surveys + eligible homes × installed package (within the average caps) + ventilation and remediation + programme staff (within the 15% allowance) + independent inspection + evaluation + contingency.

    • Warm Homes low-income grants

      England

      £4.42bn in total, 2025–26 to 2029–30, price basis not stated by the source (ledger C-WHP-LOWINCOME)

      capital; price year not stated; 2025–26 to 2029–30; Current quoted cost

      The existing envelope; homes are funded only once awards are confirmed.

    • Energy performance upgrades per home (average cap)

      Per home under Warm Homes: Local Grant

      £16,600 per home (average across a project)

      capital; 2026 prices; April 2025 to March 2028; Current quoted cost

      A published maximum average grant, not a measured cost; a separate £16,600 average cap applies to low-carbon heating.

      Source: Department for Energy Security and Net Zero, Warm Homes: Local Grant – policy guidance for local authorities (updated June/July 2026) (Section 6.1, Table 8)

    • Administration and ancillary costs

      Per WH:LG project

      Not yet established share of project spend (range Up to 15% of total project spend)

      recurring; price year not stated; Project lifetime; Not yet established

      Source: Department for Energy Security and Net Zero, Warm Homes: Local Grant – policy guidance for local authorities (updated June/July 2026) (Summary table (A&A budget))

    • Surveys, independent inspection, remediation and monitoring

      Homes selected by need

      Not yet costed (ledger C-A18-QUALITY)

      recurring; price year not stated; From the first awards; Not yet established

    • Linked health and energy evaluation

      First set of councils

      Not yet established per evaluation

      one-off revenue; price year not stated; Two heating seasons; Not yet established

    10.Who pays, and what is missing

    Programme envelope (a possible route, not an award)
    Warm Homes Plan low-income grant allocations: £4.42bn, 2025–26 to 2029–30
    Allocation committed to this change
    None
    Remaining gap
    Inspection, remediation and evaluation costs are not established; the £4.4bn is a programme envelope, not an award to this change.
    Proposed financing
    Warm Homes low-income grants (including the administration allowance) for installation and inspection; a DESNZ or NIHR evaluation budget for the health study.
    Responsible payer
    central government, landlords
    Budget displaced
    Other homes the same grant could treat; installer time for other work.

    11.First milestone and time to a useful result

    Inspection and remediation standard in scheme rules; first health-referred homes surveyed. (Owner: DESNZ with councils. Proposed by UK Facts, not an official deadline.)

    Time to first useful result: Warmth and energy use after one heating season; health outcomes after two.

    What could delay it: Installer and inspector capacity is available. Health data can be linked lawfully. Delivery under the local grant speeds up (it has been slow to report).

    12.How we would know

    Baseline
    Indoor temperature, weather-adjusted energy use, bills and health of selected households before work.
    Comparison
    Eligible homes treated later (a phased or waiting-list comparison).
    Leading indicator
    Inspections passed first time and defects remedied.
    Follow-up
    Two heating seasons after installation.
    Continue if
    Measured savings and warmth hold after inspection.
    Adapt if
    Defect rates are high or savings fall well below survey estimates.
    Stop if
    A measure causes defects; stop that measure.
    Thresholds
    Not yet set: Set before launch once power, budget and baseline are known, from the business case and evaluation design.

    What is not yet known, and how to find out

    • What would independent inspection and remediation cost per home? (cost)Next step: Obtain current quotes and label the price year.Scope: Inspection, remediation and monitoring per home · Data or quotes needed: Quotes from inspectors and retrofit coordinators; defect rates from scheme data · Who can estimate it: DESNZ with councils and TrustMark
    • Do health gains appear in English homes? (effect)Next step: A phased, health-linked evaluation in the first councils.Defensible route: bounded pilot

    Sources last checked 4 October 2026 · Owner: Evidence editor (James Harris) · Next check: DESNZ Warm Homes: Local Grant statistics, October 2026 (26 November 2026) or the first trigger: DESNZ annual fuel poverty statistics for England (usually published early in the year; date not announced when reviewed).

    More decision briefs on other pages

    What it would take

    The order things have to happen in, who pays, and the effects and appraisals on record.

    The order things have to happen in

    1. First, the prerequisite

      Survey homes; rerun levy modelling on the post-April 2026 baseline

      Owner: Councils and assessors; DESNZ

      No date: the timing depends on the steps before it.

    2. Then, the decision

      Award grants to named schemes; decide the levy design and compensation

      Owner: DESNZ and HM Treasury

      No date: the timing depends on the steps before it.

    3. Then, delivery

      Install, inspect and fix defects; phase in pricing with protection

      Owner: Accredited installers; Ofgem and suppliers

      No date: the timing depends on the steps before it.

    4. Finally, the measured outcome

      Lower weather-adjusted energy use and fuel poverty

      Owner: DESNZ statistics

      No date: the timing depends on the steps before it.

    5. Then, delivery

      Issue Gate 2 connection offers (Phase 1 deadline extended to 31 October 2026)

      Owner: NESO and network companies

      31 October 2026 (Ofgem letter, 2 October 2026) — source

    Who pays, and what is still missing

    Cost, committed funding and the remaining gap for the same scope and years. A programme envelope is not an award to a project; a proposal is not committed money. No total is shown because these costs are on different bases or periods and cannot be added.

    Cost and funding ledger

    • Warm Homes Plan: low-income home grants

      A18 · capital · published programme envelope

      Amount
      £4.42bn in total, 2025–26 to 2029–30, price basis not stated by the source
      Who pays
      central government
      Committed
      None identified
      Proposed, not committed
      £4.42bn (Warm Homes Plan low-income grant allocations)
      Gap
      Not established
    • Property surveys, installation quality checks, remediation and monitoring

      A18 · recurring spending · not costed

      Amount
      Not yet costed
      Who pays
      central government, landlords, households
      Committed
      None identified
      Proposed, not committed
      —
      Gap
      Not established
    • Further levy rebalancing from electricity to gas or taxation

      A17 · bill transfer · not costed

      Amount
      Not yet costed
      Who pays
      bill-payers, central government
      Committed
      None identified
      Proposed, not committed
      —
      Gap
      Not established
    • Protection for households who cannot switch from gas

      A17 · bill transfer · partial

      Amount
      Not yet costed
      Who pays
      bill-payers
      Committed
      None identified
      Proposed, not committed
      —
      Gap
      Not established

    “Not yet costed” means no defensible cost has been found — not that the action is free. Lifetime benefits, benefit-cost ratios and forecast savings are never shown here as money available to spend.

    Effects on record, with evidence ratings (6 records)

    What the evidence says each action changes

    Effects on record — these measure different outcomes, so they are not drawn on one scale
    ActionOutcome and areaEffectCompared withEvidence
    Make electricity pricing support cheaper clean heatingRunning cost of switching from a gas boiler to a heat pump Energy and billsDirection plausible; size not established—modelled; limited confidence; Great BritainNesta modelled a saving of about £400 a year for a typical switcher, on 2025 prices before 75% of the Renewables Obligation moved to taxation; not re-run on today’s baseline, so no size is shown.
    Make electricity pricing support cheaper clean heatingBills of households that stay on gas Energy and bills · harmSize not established—modelled; limited confidence; Great BritainNesta put the rise at about £76 a year for gas households not eligible for support (about £20 for some 19 million households only if other levies also move to taxation, at about £1.1bn a year), modelled on the April 2025 price cap; households that cannot switch — many tenants — bear it. Corrected 4 Oct 2026 (was “about £20 before compensation”).
    Fix cold and inefficient homes with quality-assured workGas use in homes after solid wall insulation Energy and bills−17% median gas useindicative; varies year to year and includes households choosing to heat moresimilar homes without measures; 2024 savings for measures installed in 2023evaluated; moderate confidence; England and WalesObservational comparison, mostly from government schemes; savings for cavity and loft insulation are smaller.
    Fix cold and inefficient homes with quality-assured workGeneral, respiratory and mental health of residents Health and careDirection plausible; size not established—evaluated; limited confidence; Studies in several countries, searched to 2012The review says improvements “are possible”, clearest where warmth was inadequate; no current UK estimate and no cashable NHS saving.
    Fix cold and inefficient homes with quality-assured workLow-income households counted as fuel poor Poverty and inequalityDirection plausible; size not established—plausible spillover; limited confidence; EnglandThe fall in the headline count partly follows from the definition. Whether hardship actually falls depends on real bills, heating behaviour and prices, which the count does not measure.
    Fix cold and inefficient homes with quality-assured workDamp and mould after poorly specified or installed insulation Housing · harmSize not established—plausible spillover; limited confidence; EnglandThis is why A18 pairs grants with a survey before work and checks after it. No national rate of defects is published in the sources we checked.

    How we would know

    Households in fuel poverty; Price cap at typical use (dual fuel, direct debit); Electricity-to-gas unit price ratio in the cap; and 1 more.

    The outcome measures to watch. A baseline is where we start, not a target; where there is no official target we say so.

    Measured results

    What each option would be judged on, and the latest value of the measures already on this page. A measure moving is not proof that an option caused it.

    Where the ideas come from

    Research, counter-evidence and methods (15 sources; 2 claims held back)

    Counter-evidence and criticism

    • Warm homes, inspected before payment: Savings vary year to year and include households choosing to heat more; health effects are uncertain and the review is old. (Cochrane / Hilary Thomson and colleagues)
    • Make electricity pricing support cheaper clean heating: After Budget 2025 policy costs are about a tenth of a typical bill, so further rebalancing has less to move; networks are about a third. (UK Energy Research Centre)
    • Connect the power Britain needs: Deadlines have already slipped twice; network reinforcement, not the queue order, may be the binding constraint. (Ofgem)

    Claims held back

    • Heat-pump switchers would save about £400 a year under levy rebalancing — Modelled on 2025 prices before 75% of the Renewables Obligation moved to taxation; not re-run on the current baseline. Needed: Re-modelling on post-April 2026 tariffs.
    • The price cap is not a maximum bill (brief weakness, cited to S13) — Not located in S13. Needed: Cite Ofgem’s own explanation of the cap.

    “Full text checked” means we read the report itself; “relevant passages” means the sections behind each figure; “summary or abstract only” means we could not read the full study, so no number from it is published here without another source.

    Other options compared — not on the shortlist (4)

    Other options compared

    Options from earlier work on this page that are not on the shortlist. They remain valid choices; their evidence is shown as before.

    • immediate reliefStatus: operating

      Targeted help with bills for low-income households

      Aims to:
      Lower net bills this winter for the households least able to pay.
      How:
      The Warm Home Discount takes £150 off the electricity bill of eligible households. From winter 2025/26 it was widened to every household on means-tested benefits.
      Who decides:
      DESNZ (scheme rules); energy suppliers (payment); DWP (data matching).
      Main constraint:
      Eligibility is tied to benefits, so low-income households not claiming them miss out; £150 is fixed whatever the household’s usage.
      Evidence:
      Limited evidence — plausible mechanism, little direct evaluation
      See the trade-offs and evidence
      What the evidence shows
      The expansion added about 2.7 million households, to around 6.1 million across Great Britain. DESNZ estimates that more households receiving the discount, together with modelled efficiency upgrades, would on their own have taken about 153,000 households out of fuel poverty between 2024 and 2025 — an effect within the official measure, not an evaluation of warmth, health or arrears.
      Policy status
      Expanded for winter 2025/26 by regulations following the June 2025 government response.
      Resources
      Rebates paid by suppliers and recovered through a levy on all domestic bills; data matching between DWP and suppliers.
      Consent and decisions needed
      Set by regulations; the cost is recovered through all customers’ bills.
      Time
      Within one winter.
      Cost and yield
      Funded by a levy on bills: about £22 a year for a typical dual-fuel household before the expansion, and about £15 a year more after it (DESNZ impact assessment). Not funded from taxation.
      Trade-offs and who pays
      Paid for by everyone else’s bills, including some low-income households who are not eligible. Relief, not a fall in the cost of energy.
      How we would know it worked
      Leading indicator: Number of rebates paid each winter. Outcome: Fuel poverty rate and the average fuel poverty gap (DESNZ). It would not be working if: Rebates paid but the fuel poverty gap and arrears among eligible households do not fall.
    • immediate reliefStatus: operating

      Move policy costs and VAT off bills

      Aims to:
      Lower unit rates and standing charges for every household.
      How:
      Costs once collected through bills are paid from general taxation instead: from April 2026, 75% of the domestic Renewables Obligation and the end of the Energy Company Obligation; from October 2026, no VAT on domestic electricity.
      Who decides:
      HM Treasury and DESNZ; Ofgem (reflects the changes in the cap).
      Main constraint:
      Competes with every other call on public spending; time-limited unless renewed.
      Evidence:
      Moderate evidence — evaluated, with limits on scope or transfer
      See the trade-offs and evidence
      What the evidence shows
      The arithmetic effect on the cap is visible in Ofgem’s components: the policy-cost line fell in April 2026. The government put the saving at about £150 a year for a typical household (£88 Renewables Obligation, £59 Energy Company Obligation, £7 VAT); Ofgem put the October VAT removal at about £45. Whether it lowers what households pay in total depends on how the taxes that fund it fall.
      Policy status
      Renewables Obligation funding from the Exchequer covers 2026–27 to 2028–29; the electricity VAT change applies from 1 October 2026.
      Resources
      Exchequer funding each year in place of bill funding.
      Consent and decisions needed
      Budget decisions by the Chancellor; any extension needs a further fiscal decision.
      Time
      Immediate on the next cap period.
      Cost and yield
      Recurring public spending; see the Budget 2025 policy costings for the scored cost. Gross transfer from taxpayers to bill-payers, not a fall in the system’s cost.
      Trade-offs and who pays
      Shifts who pays from energy users (in proportion to use) to taxpayers (in proportion to income). It helps high users most in cash terms and ended a bill-funded insulation scheme.
      How we would know it worked
      Leading indicator: Policy-cost component in Ofgem’s cap. Outcome: Cap at typical use, and energy costs as a share of income for low-income households. It would not be working if: The policy line falls but the cap rises by more because of other costs — the relief is real but swamped.
    • structuralStatus: announced

      Weaken the link between gas and electricity prices

      Aims to:
      Electricity prices that depend less on the international gas price.
      How:
      More low-carbon generation on fixed-price contracts (Contracts for Difference), more storage and interconnection, and reforms to the wholesale market, so gas plants set the price less often and generators are paid more stable amounts.
      Who decides:
      DESNZ (market design, contracts); NESO (system operation); Ofgem; generators.
      Main constraint:
      Grid connections, planning consent, supply chains and the cost of capital. Electricity still carries network and policy costs that do not fall with wholesale prices.
      Evidence:
      Limited evidence — plausible mechanism, little direct evaluation
      See the trade-offs and evidence
      What the evidence shows
      Research cited by ONS found gas plants made 43% of UK electricity in 2021 but set the wholesale price 97% of the time, so gas prices pass through to electricity. How far more fixed-price generation lowers bills depends on contract prices, network and balancing costs; there is no evaluation of the whole package. The government rejected zonal pricing in July 2025 in favour of reformed national pricing.
      Policy status
      Reformed national pricing announced July 2025; Contracts for Difference allocation rounds continue.
      Resources
      Private capital for generation, backed by bill-funded contracts; transmission build; skilled engineers.
      Consent and decisions needed
      Planning decisions for each project; Contracts for Difference budgets set by DESNZ.
      Time
      Years: projects take several years from contract to operation.
      Cost and yield
      No official estimate of the net effect on household bills is cited here; contract payments are made through bills over each contract’s term.
      Trade-offs and who pays
      Fixed contracts protect against gas spikes but can cost more than the market when gas is cheap; new lines and plants affect local landscapes.
      How we would know it worked
      Leading indicator: Share of hours in which gas sets the wholesale price. Outcome: Wholesale component of the cap, adjusted for consumption, during a gas price spike. It would not be working if: A gas spike still moves the wholesale component as much as in 2022.
    • capacityStatus: operating

      Connect projects to the grid faster

      Aims to:
      Cheaper generation and storage connected sooner, rather than waiting years in a queue.
      How:
      Connections reform replaces “first come, first served” with “first ready and needed”, removing speculative projects from the queue so viable ones get earlier dates.
      Who decides:
      NESO (queue management); Ofgem (approval); transmission and distribution network operators (build).
      Main constraint:
      Physical network build, which reform does not speed up by itself; local consent for new lines.
      Evidence:
      Not evaluated — a mechanism to test, not an evidenced fix
      See the trade-offs and evidence
      What the evidence shows
      Ofgem approved NESO’s reform in April 2025; NESO says it can remove up to two-thirds of the oversubscribed queue. Faster connection dates are a delivery measure, not yet evidence of lower bills.
      Policy status
      Gated application process in force since 2025.
      Resources
      Network investment through Ofgem’s price controls, paid through bills; planning and supply-chain capacity for new lines and substations.
      Consent and decisions needed
      Ofgem code decisions; planning consent for transmission projects.
      Time
      Revised connection offers from 2025–26; physical reinforcement takes years.
      Cost and yield
      Administrative cost of reform is small; the network build it enables is paid through the networks part of every bill.
      Trade-offs and who pays
      Projects that lose their queue position bear the cost; more network spending raises the networks component of bills before any wholesale saving arrives.
      How we would know it worked
      Leading indicator: Median time from application to connection. Outcome: Wholesale and balancing costs per MWh over time. It would not be working if: Connection dates improve but network and balancing costs rise faster than any wholesale saving.
    The options side by side
    OptionResourcesTimeEvidenceOutcome to watch
    Targeted help with bills for low-income householdsRebates paid by suppliers and recovered through a levy on all domestic bills; data matching between DWP and suppliers.Within one winter.limitedFuel poverty rate and the average fuel poverty gap (DESNZ).
    Move policy costs and VAT off billsExchequer funding each year in place of bill funding.Immediate on the next cap period.moderateCap at typical use, and energy costs as a share of income for low-income households.
    Weaken the link between gas and electricity pricesPrivate capital for generation, backed by bill-funded contracts; transmission build; skilled engineers.Years: projects take several years from contract to operation.limitedWholesale component of the cap, adjusted for consumption, during a gas price spike.
    Connect projects to the grid fasterNetwork investment through Ofgem’s price controls, paid through bills; planning and supply-chain capacity for new lines and substations.Revised connection offers from 2025–26; physical reinforcement takes years.not evaluatedWholesale and balancing costs per MWh over time.

    Plan reviewed 2026-10-07. How we judge evidence.