CIH response to ESNZ Committee inquiry into warm and comfortable homes

CIH is a member of the End Fuel Poverty Coalition, and we generally support the priorities the coalition has set out on the Warm Homes Plan (‘the Plan’)[1].  We would like to add evidence on four important priorities that would accelerate the delivery of the Plan if resolved quickly. 

Minimum Energy Efficiency Standards (MEES) and the Home Energy Model (HEM)

The government must prioritise finalising the regulatory requirements and guidance for Minimum Energy Efficiency Standards (MEES) in both rented sectors. We are particularly concerned that the delay in finalising these requirements is impacting on the social housing sector’s ability to plan upgrades efficiently and effectively between now and 2030, and over the medium and long-term. 

For several years prior to 2026, most of the social housing sector was working towards a rating of C on the current energy performance measurement regime, the Standard Assessment Procedure (SAP) (usually termed ‘EPC Band C’). It was widely expected prior to 2025 that this would be the minimum regulatory requirement to comply with MEES[2].  However, the government’s final MEES decision withdrew this target and replaced it with as-yet unknown minimum requirements on the government’s forthcoming energy performance measurement regime, the Home Energy Model (HEM)[3]. 

The major reform introduced through the MEES and HEM policies is to replace the anticipated target of EPC Band C with a target based on three new, alternative HEM metrics[4].  These metrics are called Fabric, Heating, and Smart. Social housing providers are required to achieve a rating of C on one of these three metrics for all homes by 1 April 2030, and on two of the three metrics by 1 April 2039 (unless a valid exemption applies). For example, a home will be considered compliant with MEES in 2039 if it meets Smart C and Heating C. 

CIH supports the broad direction of these reforms which, while centred on tackling fuel poverty, also have an important secondary aim: the decarbonisation of social homes, in line with our statutory net zero target and carbon budgets. However, at the time of writing, the target metrics themselves are not finalised. The government consulted on the minimum requirement to meet C on the Heating, Smart, and Fabric HEM metrics between 21 January 2026 and 18 March 2026. The response to this consultation has not yet been published. As a result, the minimum regulatory requirement to comply with MEES is not yet known. 

It is therefore increasingly urgent for the government to publish the outcome of the aforementioned consultation. Even a partial response, setting out the C bandings for each of the three regulated HEM metrics, would enable social housing providers to understand the required levels of investment for meeting MEES (in both 2030 and 2039), and therefore allow them to begin allocating additional resources in their business planning between now and 2030, and over the medium and long-term. 

The Heat Network Technical Assurance Scheme (HNTAS)

The Plan set out an ambition to unlock and accelerate the potential of heat networks. One of the ways the Plan approaches this is by pledging action to tackle, “unregulated, under invested and inefficient” heat networks[5].  The centrepiece of this action is, “mandatory minimum technical standards for heat networks underpinned by an assurance scheme”, which has subsequently been termed the Heat Network Technical Assurance Scheme (HNTAS)[6].  The design of HNTAS was consulted on between 21 January 2026 and 15 April 2026, and at the time of writing, we are still awaiting the outcome of the consultation.

CIH strongly agrees with the overarching aims of HNTAS. Too many heat networks are inefficient, subject to outages, and unaffordable for many people who rely on them for warmth. However, we do have some concerns about the complexity and cost of the policy design that was consulted on. 

The total estimated cost for upgrading heat networks to meet HNTAS in Great Britain is stated in the consultation options assessment to be around £3.9 billion over at least 10 years[7].  Of existing heat networks across Britain, 60% are in the not-for-profit sector,[8]  and CIH understands that many heat networks owned and/or operated by not-for-profit entities such as social housing providers actually operate at a loss. There is therefore a significant cost associated with the proposals that will have to be met for HNTAS compliance to be achieved. 

The Plan commits £15 million a year to 2029/30 for the Heat Network Efficiency Scheme (HNES), which at the time of writing is the only government scheme that provides financial support to improve the technical performance of existing heat networks[9].  However, even if we make the unrealistic assumption that all of this funding goes to not-for-profit heat networks, it will cover only a tiny fraction of the overall expenditure described in the consultation options assessment. 

It is therefore unclear how the government expects the costs of meeting HNTAS compliance in the not-for-profit sector to be paid for[10].  In social housing, if HNTAS is primarily paid for by rental income, it will severely compromise the ability of the sector to build desperately needed social and affordable homes[11].  Alternatively, some or most of the costs could be passed onto social housing residents and leaseholders through service charge increases, which seems equally undesirable, given that service charges are already unaffordable for many households. 

At the same time, we are not clear how adjacent policy, such as the cap on social housing repairs costs under Florrie’s Law,[12]  will impact the distribution of HNTAS costs across landlords and residents, or if the government anticipates no costs at all to fall on residents, as previous administrations have intended to be the case for some building safety remediation costs[13].  

For these reasons, the government urgently needs to set out its final decision on the policy design of HNTAS, and how it expects the technical improvements to be paid for. CIH supports the prospect of the Warm Homes Fund (WHF), the design of which has also been consulted on in 2026, providing financial support to not-for-profit heat networks to help cover the costs of the improvements[14].  

Heat adaptation and the need for a more ambitious plan 

The Plan acknowledged the urgency of tackling overheating in homes. It recognised that, “integrating adaptation into home upgrade policy is essential to mitigate overheating and other climate-related impacts.”[15]  Some very welcome policy commitments have followed, such as the inclusion of air-to-air heat pumps in the Boiler Upgrade Scheme, and a stated intention to, “embed the most appropriate and cost-effective passing cooling measures into funding schemes targeting low-income households and social housing.” [16]

While these commitments are essential, CIH believes that a more ambitious plan is needed to protect homes and communities from overheating. This plan will necessarily cross individual government departments, and will require collaboration between the Cabinet Office, DEFRA, DESNZ, and MHCLG.

CIH has a longstanding programme of policy and research work that has examined prospective solutions to overheating in homes[17].  We are especially supportive of the use of the cooling hierarchy as a guiding principle for heat adaptation, and the development of financial support, such as a Hot Weather Payment, to help low-income and vulnerable households with the running costs of air-to-air heat pumps, air conditioning, and other forms of electricity-reliant active cooling in very hot weather[18].  We also support a rigorous review or ‘stress-test’ of Part O of the Building Regulations, which should go further than the recently announced technical review to robustly assess if the homes we are building are resilient to the temperatures and climate we are already seeing today, and will increasingly see in the future[19].  

Whatever its detail, a more ambitious plan for preventing overheating in homes is required, and the government should move quickly to set out how it will supplement the Warm Homes Plan with a parallel strategy to keep homes safe, cool, and healthy all year-round. 

Finalising how the capital allocation will be spent

Lastly, a significant proportion of the £15 billion committed to the Plan is not yet in delivery or confirmed. £5 billion of investment, implemented through financial transactions, has been allocated to the WHF. The design and priorities of the WHF were consulted on between 24 March 2026 and 1 June 2026. CIH responded with our view that it could support social housing providers to upgrade complex mixed-tenure blocks and meet HNTAS, as well as supporting middle-income households with low-interest loans to cover the high upfront cost of low-carbon technologies[20].  Concluding the design of the WHF, and quickly shifting it into delivery, is a critical priority, especially given the amount of funding – a full third of the Plan’s overall envelope – that sits behind it waiting for deployment. 

Meanwhile, we understand that around £3 billion of the Plan’s funding for low-income households has yet to be allocated. This funding should be allocated and deployed as quickly as possible, either at the 2026 Autumn Budget or at a subsequent Spending Review. 

Yes. In our view, the Warm Homes Agency (‘the Agency’) should have a remit that includes the delivery of support to households and landlords to make their homes safe and affordable to cool, heat, and power. Its focus should in other words be holistic and concerned with supporting households and landlords to upgrade their homes to good levels of thermal comfort all year-round.  

We feel this is particularly important given the multiplying, and often confusing, range of upgrades that are being discussed to keep homes cool and safe in summer. In this landscape, active cooling solutions such as air conditioning and air-to-air heat pumps exist alongside passive solutions such as shade sails, awnings, external blinds, and shutters. Among this proliferation of different solutions, households and landlords will need tailored, personalised support regarding the cooling solutions that might work best for them, including their upfront cost, suitability for their home, upkeep and maintenance requirements, any running costs, and rights around redress. 

Generally, CIH believes that any support given to households and landlords about cooling should follow the principles of the cooling hierarchy, whereby in broad terms, external shading, passive measures, and insulation are considered before active solutions requiring electricity consumption. Even in the 22% of homes where active cooling may be needed,[21] prioritising passive cooling and shading first is a vital way of reducing carbon emissions, minimising the discharge of waste heat into the environment, softening demand on the energy grid, and decreasing the ongoing electricity costs of running the unit, which may be difficult for lower-income households to afford[22].  

However, as with heating, it is clear that different solutions will work best in different types of home, for different occupants, with different socio-economic characteristics. The Agency should be designed and resourced in such a way that households and landlords are supported to navigate these decisions and their implications. 

[1] See End Fuel Poverty Coalition (2026) Welcome emails to new Prime Minister and selected ministers.

[2] To our knowledge, this requirement was first mentioned in the Clean Growth Strategy (2017), p.13, and was mentioned in many subsequent government documents published between 2017 and 2024 as an intended policy without ever being consulted on.

[3] MHCLG (2026) Consultation on Home Energy Model: Energy Performance Certificates. All references to the HEM metrics consultation are to this.

[4] MHCLG (2026) Consultation outcome: Improving the energy efficiency of socially rented homes in England.

[5] DESNZ (2026) Warm Homes Plan, p.101.

[6] DESNZ (2026) Warm Homes Plan, p.111.

[7] DESNZ (2026) Heat Networks Technical Assurance Scheme: Impact Assessment, p. 15.

[8] Ofgem (2025) Consultation on Heat networks regulation: authorisation conditions and guidance on measures to mitigate the risk and impact of financial failure, p.18.

[9] DESNZ (2026) Warm Homes Plan, p.98.

[10] The Impact Assessment (note 7) is contradictory on this. It is stated on p.4 that “in the short run, upgrade costs will be passed on to consumers.” However, elsewhere on p.16 it states that “it is difficult to know the level of pass through [of capex costs] from businesses to households and will vary dependent on the type of heat network.” What is meant by ‘type’ in this sentence is not explained.

[11] CIH (2026) Response to Department for Energy Security and Net Zero (DESNZ) consultation on the Heat Network Technical Assurance Scheme (HNTAS).

[12] Florrie’s Law was introduced in 2014, and caps the amount social housing providers can charge leaseholders for repairs to their homes at £10,000 in any five-year period outside of London, and £15,000 in any five-year period in London. Information provided to CIH by our members and sector partners during the HNTAS consultation period suggests that the costs per dwelling of reaching HNTAS compliance will often exceed £10,000.

[13] It is illegal for building owners to pass historical safety remediation and cladding system costs onto qualifying leaseholders. It is also illegal for building owners to pass historical safety remediation costs onto any leaseholder if the building owner was, or was associated with, the developer responsible for that historical safety defect. Feasibly, failing heat networks constructed to poor efficiency and reliability standards by developers some decades ago could be approached the same way.

[14] CIH (2026) Response to Department for Energy Security and Net Zero (DESNZ) call for evidence on the design of the Warm Homes Fund.

[15] DESNZ (2026) Warm Homes Plan, p.44.

[16] DESNZ (2026) Warm Homes Plan, p.44.

[17] CIH (2025) Heat adaptation in the UK: policy brief; CIH (2026) A strategy to reduce the risk of overheating in London’s homes; CIH (2026) Improving heat risk communication in England: lessons for a hotter future, which are based on peer-reviewed academic research.

[18] Scott, M. and Khosravi, M. (2026) Why we should follow the cooling hierarchy before installing air conditioning in UK homes; CIH and CaCHE (2025) Turning up the heat: nine discussion questions on overheating in domestic homes in the UK, pp.9-10.

[19] This recommendation was recently adopted by the Housing, Communities and Local Government Committee (2026) Housing Conditions in England: new-build homes.

[20] CIH (2026) Response to Department for Energy Security and Net Zero (DESNZ) call for evidence on the design of the Warm Homes Fund.

[21] 22% is the Climate Change Committee’s estimate of the proportion of UK housing that would require active cooling in future climate conditions of 2°C global warming. See Climate Change Committee (2026) A Well-Adapted UK: The Fourth Independent Assessment of UK Climate Risk (CCRA4-IA).

[22] Citizens Advice (2026) Nearly half of Brits feel they lack basic control to stop homes overheating, says Citizens Advice; Scott, M. and Khosravi, M. (2026) Why we should follow the cooling hierarchy before installing air conditioning in UK homes; Social Market Foundation (2026) Britain’s cooling debate is blind to passive options.

For more information on our response please email Matthew Scott, Policy Manager at matthew.scott@cih.org.