Energy and Buildings Policy in Wales: What the Welsh Government Controls

Energy policy for homes in Wales is split between two governments. Westminster keeps the levers over the energy market itself: the price cap, supplier licensing, the electricity and gas networks and the wider UK regulatory framework. The Welsh Government, in Cardiff, controls the rules that shape the building you live in: building regulations, planning policy, housing standards and the schemes that pay for insulation and heating upgrades. When Ofgem and consumer bodies signpost help with home energy efficiency, they point Welsh householders to the government of Wales as the delivery body¹, and help with home energy bills for Welsh residents runs through gov.wales rather than a UK-wide scheme².

The Welsh Government's stated ambitions are specific and dated. Its aim is that by 2035 no more than 5% of Welsh households live in fuel poverty, and none in persistent or severe fuel poverty³. It wants at least 1.5GW of renewable energy capacity in Wales to be locally owned by 2035, excluding heat pumps⁴. And the plan for Welsh homes, set out in the Warm Homes Programme impact assessment, is that they reach net zero by 2050, with publicly owned buildings and social housing leading the way⁵.

What Cardiff controls, and what it does not

The devolution settlement matters to a householder in practical ways. The split looks like this:

The Welsh Government decides the content of the Building Regulations that apply in Wales, including the approved documents that set energy efficiency and ventilation standards, and it runs its own consultation and amendment process separate from England's. It sets planning policy for Wales through Planning Policy Wales and the associated permitted development orders. It owns housing policy, including the quality standards that social housing must meet. And it funds and designs the schemes householders actually encounter: Warm Homes and Nest for those on low incomes, and Green Homes Wales for loans.

What Cardiff does not control is the price of energy, the tariffs suppliers offer, the operation of the grid, or the licensing of suppliers. Those sit with Westminster, Ofgem and the Department for Energy Security and Net Zero. The Welsh Government has been explicit about the boundary: in a March 2026 written statement on rising energy costs it called for the UK Government to take action to support households where the energy price cap mechanisms do not provide sufficient protection against rising prices⁸. In other words, Wales can insulate your home and set the standard your new boiler installation must meet, but it cannot cap your bill.

Within its own powers, the Welsh Government's reach is wide:

• A moratorium, in place since 2021, on large Energy from Waste plants above 10MW⁹
• A commitment to reviewing the heat network zoning powers in the UK Energy Bill and considering the benefits of adopting a similar approach in Wales¹⁰
• A heat strategy run as a Welsh Government consultation, with the Welsh Government as data controller¹¹
• Free impartial energy savings advice offered to all householders in Wales, not only to those who qualify for grant support⁵

The Welsh energy framework and the plans inside it

Wales does not have a single energy act. Instead there is a layered set of documents that a householder trying to follow policy will meet in sequence.

The top layer is the commitment, made in the Preparing Wales for a Renewable Energy 2050 work, to the creation of a national energy plan by 2024, and to the Welsh Government presenting a vision for energy in Wales to 2050 by 2025, including detail on renewable energy production and grid development¹². The National Energy Plan is described as setting out the energy system changes required to achieve net zero by 2050, while delivering a secure and affordable energy system in Wales¹³.

Beneath that sit the delivery bodies. The Welsh Government Energy Service supports renewable energy projects in Wales from the concept stage through to financial close and completion¹³. The Development Bank of Wales manages Green Homes Wales on the Welsh Government's behalf¹⁴. The renewable energy deep dive work carries the target of at least 1.5GW of locally owned renewable capacity by 2035, and continuing to keep pace with consumption thereafter⁴, with the stated aim of maximising local ownership so that economic and social benefits stay in Wales⁴.

The third layer is heat. The draft heat strategy for Wales, consulted on in 2023, addresses how the 2050 target translates into the way homes are heated, and it feeds into the National Energy Plan alongside the Future Energy Grids in Wales project, regional energy strategies and the energy targets⁴. For a household, the practical significance is that the framework pushes in one consistent direction: less energy wasted, more generation owned locally, and heat moved away from fossil fuels.

Nest and Warm Homes eligibility and funding

The Warm Homes Programme is the Welsh Government's main scheme for households that cannot pay for improvements themselves. Its stated focus is on households least able to pay, meaning households in or at risk of fuel poverty and those in severe fuel poverty, in the owner occupier, private rented and housing co-operative sectors³. The approach is described as "a fabric, worst and low carbon first approach, delivering measures to improve the energy efficiency of the least thermally efficient low-income households in Wales"³.

Nest is the part of the programme most householders meet. It exists to help households facing an immediate risk to their health and wellbeing due to a lack of essential heating or hot water¹⁵. In 2022 to 2023 the Welsh Government provided £26.9m of funding to deliver the Warm Homes Programme Nest Scheme⁶.

Eligibility turns on two things: the household's circumstances and the home's energy rating.

The scheme is described more generally as offering free energy upgrades for houses with a poor EPC rating¹⁷. What is funded includes the replacement of a boiler or electric storage heaters to ensure a safe and reliable heating system¹⁵.

Applying is by phone: call Nest free on 0808 808 2244 to check eligibility¹⁵.

The long-term ambition behind the programme is stated plainly:

Green Homes Wales loans regardless of income

Nest is means tested. Households above its income thresholds, or whose homes do not meet the EPC conditions, have a second route: Green Homes Wales, a Welsh Government initiative managed by the Development Bank of Wales¹⁴. The scheme supports the installation, in domestic properties located in Wales, of certain types of energy efficiency improvement measures and low carbon heating systems¹⁸. Its stated purpose is to help households implement energy and carbon-saving measures which can lower both energy consumption and energy bills¹⁹.

Because it is a loan scheme rather than a grant, the standard terms and conditions of the Development Bank of Wales apply, and the eligibility rules are set out in those scheme rules rather than in a benefit test¹⁸. One detail matters for anyone planning insulation: ventilation systems are eligible for loan funding support where insulation is being installed, or where additionally recommended by the Retrofit Coordinator¹⁴. That reflects the building regulations position, covered below, that energy work must not leave a home worse ventilated than before.

For a household thinking about energy independence, Green Homes Wales is the Welsh route to paying for solar, storage and heat pumps when no grant applies. The dependence to note is financial rather than technical: the loan is repaid, and the scheme's continuation depends on Welsh Government funding decisions.

Changing fuel source and fuel poverty concerns

The official fuel poverty statistics for Wales are modelled, not surveyed: household energy requirements are modelled using the Building Research Establishment Domestic Energy Model, BREDEM 2012 version 1.1, and the October 2024 estimates published in 2025 rest on that methodology²⁰. The headline figures from those estimates include 22% of households in social housing in fuel poverty, and 23% of households in dwellings with central heating²⁰. Earlier work put the position more starkly: despite numerous energy efficiency initiatives, almost a quarter of Welsh households experience fuel poverty²¹.

The Welsh Government's target is that by 2035 no more than 5% of all Welsh households live in fuel poverty and no households live in persistent or severe fuel poverty³. More detail on how fuel poverty is defined and measured across the four nations is on the fuel poverty policy page.

The difficult finding sits in the decarbonisation analysis. The Homes of Today for Tomorrow work on decarbonising Welsh housing between 2020 and 2050 warns that "light retrofit for decarbonisation (replacing conventional fossil fuel heating systems with low carbon - typically electric heat)" is likely to increase fuel bills and consequently fuel poverty²¹. The point is simple and important: swapping a gas boiler for an electric system in a poorly insulated home can make a household poorer, not greener.

One further position is settled: off-gas areas in Wales will not use hydrogen⁹. Households off the gas grid looking at their future heating options are, on current Welsh policy, choosing between heat pumps, direct electric and heat networks, not hydrogen.

Clean energy requirements for new build homes

For new build, the direction was set early. In 2020 the Welsh Government proposed tough new standards on new homes, to be implemented in stages over the next 5 years, covering energy efficiency, low carbon heating and energy generation such as photovoltaic panels, heat pumps or district heat networks²². The Part L impact assessment framed the 2022 changes as the basis for introducing a performance standard incorporating low-carbon heat in new homes by 2025²³.

The changes made in 2022 to Part L for new dwellings included:

• Improved fabric
• Photovoltaics
• Wastewater heat recovery
• Air tightness tests for all new homes
• Removal of the fuel factors
• Self-regulating devices in the notional specification²³

The 2022 amendment regulations covered energy efficiency, ventilation and overheating together²⁴.

Social housing is treated as the pathfinder. The Welsh Government committed to building 20,000 low carbon social homes for rent over five years, announced in 2021⁷, alongside a ban on fossil fuels to heat newly built social homes⁷. A further £150m was committed for insulation, clean energy and carbon reduction in social homes⁷. The draft heat strategy adds that all new social housing must have an Energy Pathway in place to achieve EPC A by 2033, or by a later date the Welsh Government has authorised¹⁰. Local authority housing must meet the Welsh Housing Quality Standard²⁵, and the 2016 to 2026 energy efficiency strategy also backed supporting new technology like smart meters in family homes²⁵.

The scale of the task is quantified in Welsh Government-commissioned case study material: Welsh homes are responsible for 27% of all energy consumed and 15% of all demand-side greenhouse gas emissions, and the decarbonisation programme requires Welsh homes to have reduced carbon demand by 80% by 2050²⁶. Estimates of homes' share of Welsh emissions differ across documents: one impact assessment puts homes, new and existing, at 20% of greenhouse gas emissions²³, while the Warm Homes impact assessment puts Welsh homes at approximately 10% of all greenhouse gas emissions in Wales in 2021, counting emissions from electricity consumption separately⁵. The difference turns on what is counted as a home's emissions; both are official figures and they differ.

Welsh Building Regulations documents on energy and airflow

Building work in Wales is governed by the Building Regulations 2010 as they apply in Wales, with Welsh-specific approved documents. The 2026 edition of Approved Document L Volume 1 gives guidance for compliance with the Building Regulations for building work carried out in Wales²⁷, and the consultation version describes its role as providing "practical guidance on ways of complying with the energy efficiency requirements of the Building Regulations 2010"²⁸. The full detail of the Welsh system is on the building regulations in Wales page.

Ventilation is handled by Approved Document F, Volume 1: Dwellings, 2022 edition, introduced by the Building Regulations etc. (Amendment) (Wales) Regulations 2022²⁴. The key rule for anyone having energy work done is in those same regulations:

Insulation that seals up a home without ventilation provision is therefore not compliant.

Notification duties follow completion. For new dwellings, the building control body must be notified once the work is complete of the as-built target primary energy rate, dwelling primary energy rate, target emission rate, dwelling emission rate, target energy use intensity, dwelling energy use intensity, fabric performance values and the list of specifications²⁷. The same five day deadline applies to giving the local authority the as-built notice or a certificate from an accredited energy assessor²⁷.

Information must also reach the owner. Not later than five days after the work has been completed, the person carrying out the work must provide the owner with sufficient information about the use of fuel and power²⁹, and the same deadline applies to on-site electricity generation systems, including their operation and maintenance requirements²⁸. Before work starts, Regulation 25A requires in Wales that, not later than the beginning of the day before the day on which the work starts, the building control authority is given a notice stating that the energy analysis has been undertaken, is documented and the documentation is available for verification³⁰. The energy efficiency requirements themselves apply to the erection, extension of, and any work to or in connection with a building that is a roofed construction having walls, uses energy to condition the indoor climate, and is not in an excluded category³⁰.

Airflow after energy improvements to existing properties

When Part L work is carried out on an existing dwelling, Approved Document F groups the work into categories, and the ventilation expectations rise with the extent of the work. The consultation draft of the Welsh Approved Document F sets out the detail, and several of its figures are the ones an installer will work to³¹.

In wet rooms, the rule is direct: "Intermittent extract fans should be fitted in all wet rooms."³¹ Typical extract rates in the guidance are 15 l/s for a bathroom and 30 l/s for a utility room, with kitchens ducted to outside³¹.

A worked example in the impact assessment for existing dwellings shows what a compliant natural ventilation system looks like: 12 background ventilators of 5000 mm2 slot-type in the head of the window, a 15 l/s intermittent fan in the bathroom, a 30 l/s intermittent fan in the utility room, and the existing kitchen canopy reconfigured to duct to outside²³.

The connection to funding is worth noting: because Green Homes Wales loans fund insulation, and the scheme rules make ventilation systems eligible for loan funding where insulation is being installed or where a Retrofit Coordinator recommends them¹⁴, a household financing insulation through the scheme can finance the ventilation work the regulations require at the same time.

Welsh planning permission exemptions for energy upgrades

Permitted development rights in Wales are made under Welsh instruments, not the English ones. Two orders matter historically: the Town and Country Planning (General Permitted Development) (Amendment) (Wales) Order 2013³² and the 2019 Order, which amended the 1995 General Permitted Development Order and added provisions for minor operations for recharging electric vehicles, along with schedules substituting Part 24 and covering the installation of devolved associated lines³³. The practical effect for householders is that an EV charge point at home is treated as a minor operation rather than development needing an application.

For solar, the Welsh guidance on permitted development rights for solar photovoltaic and thermal panels applies to installations where capacity does not exceed 50kW for the generation of electricity, and 45kW for the production of heat³⁴. Those thresholds are far above anything a house would install, so a domestic array is well within the right. General planning guidance likewise confirms that in many cases, even in conservation areas, homes can have solar panels without requiring planning permission from the council under permitted development³⁵. Listed buildings remain the significant exception, and a conservation area check is worth making before ordering equipment.

Heat pumps are the acknowledged gap. The Welsh Government's own draft heat strategy states that "the current permitted development rights related to heat pumps are a barrier to heat pump installation rollout"¹¹. Unlike solar and EV charging, a heat pump's outdoor unit and acoustic issues are not fully covered by Welsh permitted development rights, so householders may need a planning application where an English householder would not. The general rules are on the permitted development rights page.

Local benefit and fuel choices in planning policy

Planning Policy Wales is where the Welsh Government's energy ambitions meet the planning system, and it differs from England in emphasis: local ownership and local benefit are written into the policy rather than left to the market.

The Preparing Wales for a Renewable Energy 2050 consultation proposed that all new energy projects should have at least an element of local ownership, with an aspiration of 1.5GW of local ownership of renewable electricity and heat capacity in Wales by 2035¹². It suggested a size threshold, for example 5MW, below which projects would be treated differently¹². Its first recommendation on capturing the value of renewable energy projects to Wales was to provide support to local authorities, including a ministerial directive and updated guidance, to develop a local planning policy environment that supports delivery of more renewables through planning and land use¹².

On heat, the draft heat strategy commits the Welsh Government to consult on introducing planning policy that restricts fossil fuel heating in new developments, with a firm date communicated as a ban¹⁰. Combined with the existing ban on fossil fuel heating in newly built social homes⁷, the direction is that new development in Wales is expected to be fossil-free, with the planning system used as one of the levers.

For householders, the significance is that Welsh planning policy is deliberately aligned with the energy framework: the same documents that set the 1.5GW local ownership target also shape what a council will approve on your roof or in your garden.

Wales compared with England and Scotland

The differences are concrete, not just constitutional.

Building regulations. Wales amends its Building Regulations separately. The 2022 Welsh amendments covered energy efficiency, ventilation and overheating together²⁴, and Wales now has its own 2026 edition of Approved Document L Volume 1²⁷, while England works to the 2021 edition of its Approved Document L, incorporating 2023 amendments²⁹. The two documents look similar but are not interchangeable.

Wales runs its own legislative track. Wales amends the Town and Country Planning (General Permitted Development) Order 1995 through its own instruments rather than following England's, including the 2019 Order 2019 No. 330 (W. 80), which treats the installation of electric vehicle recharging points as minor operations and substitutes Part 24 of the Schedule³³. Earlier Welsh amendments include Order 2013 No. 1776 (W. 177), again applying to Wales alone³². England's Future Homes Standard, by contrast, operates through Approved Document F and Approved Document L²⁷, so the two nations diverge both in the instruments used and in the documents that carry the technical requirements.

Fuel poverty and heat policy. Wales has a dated statutory-style aim of no more than 5% of households in fuel poverty by 2035³, and its official estimates are modelled on BREDEM 2012²⁰. Scotland runs its own separate system of building standards and heat policy, covered on the energy policy in Scotland page, and England's rules are on the building regulations in England page.

Planning. Welsh permitted development is made under Welsh orders³³, and the Welsh Government itself identifies heat pump rights as a barrier in a way no equivalent English policy document does¹¹. Wales also writes local ownership of energy projects into its planning framework¹².

Housing. Wales commits its social housing sector to lead: 20,000 low carbon homes for rent⁷, a fossil fuel heating ban in new social homes⁷, EPC A pathways by 2033¹⁰ and the Welsh Housing Quality Standard for council housing²⁵.

For a household's energy independence, the Welsh picture is this: the rules and the money available to you depend on which nation you live in, and in Wales they are unusually favourable to fabric-first retrofit and locally owned generation. What remains outside Welsh control is the price of the energy your improved home still buys, and the grid connection your solar and heat pump depend on.