What SAP actually measures
EPC ratings in England and Wales are calculated using the Standard Assessment Procedure, a methodology maintained by the Building Research Establishment and approved by government. SAP assesses the energy efficiency of the dwelling based on fixed elements: insulation, glazing, heating systems, lighting, and permanently installed renewables such as roof-mounted solar photovoltaic panels.
The critical word is "installed". SAP considers technologies that are integrated into the fabric or services of the building and assessed by an accredited Domestic Energy Assessor during the inspection. Plug-in devices are currently treated as portable electric appliances and entirely excluded from the EPC assessment because they are not permanent features of the property and cannot be verified as present at future assessments or tenancies.
This creates a binary outcome for compliance-focused landlords. A technology might cut a tenant's energy use by 20 per cent, but if it doesn't meet SAP's permanence and integration criteria, it contributes nothing to the EPC rating. That makes it commercially irrelevant for a landlord facing a legal minimum of grade C by 2030.
The cost-benefit split
The landlord's complaint about the payback timeline is structurally sound. Energy efficiency improvements in rental properties create a split incentive: the landlord funds the capital expenditure, the tenant captures the reduction in bills. There is no automatic mechanism to share the benefit unless the landlord increases rent, at which point the tenant's net saving shrinks or disappears.
This has been acknowledged in government consultations and sector research for more than a decade, but it remains unresolved in policy. The 2030 minimum standard is a prohibition, not an incentive. Landlords must achieve grade C or face a letting ban. The absence of grant funding for most private landlords, combined with EPC methodology that excludes low-cost modular technology, compresses the range of affordable compliance routes.
For portfolio landlords operating on volume and tight margins, this matters. If plug-in solar panels retail at £1,500 per property and deliver no EPC improvement, that is £1,500 per unit that should be redirected towards measures that do: loft insulation, cavity wall fill, boiler replacement, or fixed solar PV. The question is whether landlords have access to clear, current technical guidance that tells them which technologies count before they commit capital.
Feed-in tariffs and current export payments
The landlord's reference to feed-in tariffs is outdated. The Feed-in Tariff scheme closed to new applicants in March 2019. It has been replaced by the Smart Export Guarantee, which requires licensed electricity suppliers with more than 150,000 customers to offer a tariff for electricity exported to the grid by small-scale renewable generators.
SEG rates are set by suppliers and vary widely, from under 4p per kWh to over 15p per kWh for time-of-use export tariffs. Eligibility requires the installation to be certified under the Microgeneration Certification Scheme. Ownership matters: the SEG contract is between the supplier and the account holder, typically the tenant in a rented property. If the tenant holds the electricity account and the plug-in solar system is registered to them, they would receive any export payments. The landlord would see no income from generation.
This further narrows the financial case for landlord investment in plug-in technology. No EPC recognition, no SEG income, and full capital cost.
The 2030 deadline and current policy status
The requirement for private rented properties in England and Wales to achieve a minimum EPC rating of C by 2030 was proposed under the previous government and consulted on in 2020 and 2021. Implementation was deferred, and as of early 2025 the policy has not been enacted in regulations. The current minimum standard remains EPC grade E, in force since April 2020.
Landlords should not assume the 2030 deadline is confirmed law. But they should also not assume it will be abandoned. Policy direction under the current government remains focused on decarbonisation of the housing stock, and a phased tightening of private rented sector energy standards is consistent with net zero commitments.
This creates planning tension. Landlords with grade D and E properties must decide whether to invest now in anticipation of the C standard, or wait for regulatory certainty and risk a later capital spike when the deadline is confirmed and the supply chain is compressed.