Walk into any letting agent's back office in England or Wales right now and you'll find a spreadsheet nobody wants to open: the EPC register, sorted by rating, with every D, E and F highlighted in red. The government's Warm Homes Plan puts a hard floor under rental-property energy performance — EPC C for new tenancies from 2028, and for all existing tenancies by 2030 — and landlords who assumed this would slip, the way so many green-home deadlines have before, are starting to realise it probably won't this time.
The consultation closed in May 2025 with broad cross-party support, and the Department for Energy Security and Net Zero has said the final regulations will be laid well ahead of the 2028 cut-off so landlords have time to plan. That's the theory. In practice, roughly 2.9 million privately rented homes in England currently sit below EPC C, according to English Housing Survey data, and the tradespeople who install insulation, air source heat pumps and double glazing are already booked up months in advance in parts of the South East and East Anglia.
What actually moves a property from D to C
An EPC rating isn't a vague impression of a home's greenness — it's a points score (SAP score) built from specific, costable interventions. Loft insulation topped up to 270mm is usually the cheapest win, often £400–£600 through an installer like Building Materials Nationwide or a local TrustMark-registered contractor. Cavity wall insulation typically adds another 5–8 points for £1,500–£2,500 depending on wall area. Where a property has solid walls — common in Victorian terraces across Leeds, Bristol and large parts of London — external or internal wall insulation runs £8,000–£15,000, and that single line item is what tips many landlords from “manageable” to “is this property still worth keeping.”
The boiler question nobody wants to answer honestly
A modern condensing combi from Worcester Bosch or Vaillant, correctly sized and commissioned, will usually get a property most of the way to a D or high D on its own. Getting to C reliably, especially on a mid-terrace with single glazing, increasingly means either a fabric-first retrofit or a heat pump — and heat pumps are not, whatever the marketing suggests, a drop-in replacement for a combi boiler in a poorly insulated Victorian house. Do the insulation first. A heat pump installed into a leaky building just means an expensive appliance working harder to lose the same heat through the walls.
The cost, in full, not the headline figure
Government modelling has floated a £10,000 per-property cap on required spend, but that number deserves scepticism — it's a cap on what a landlord can be compelled to spend under the regulations, not a forecast of what most retrofits will actually cost. A mid-terrace two-bed currently rated E, needing loft top-up, cavity insulation, new radiators and a boiler service, might land at £4,000–£6,000. A solid-wall Victorian flat needing internal wall insulation and window replacement can run to £18,000 once scaffolding, decorating make-good and displaced-tenant costs are added in. Get three quotes, not one — installer pricing for the same spec varies by 40% or more across the same postcode, and the cheapest quote is not automatically the one to take if the survey behind it looks rushed.
- Loft insulation top-up: £400–£600, fastest payback
- Cavity wall insulation: £1,500–£2,500 where cavities exist
- Solid wall insulation (internal or external): £8,000–£15,000
- Double glazing replacement, per property: £4,000–£9,000
- Air source heat pump, post-insulation: £7,000–£13,000 after the Boiler Upgrade Scheme grant is deducted — and the grant itself has been extended but is not guaranteed to survive every future Budget, so don't bank a purchase decision on it lasting past this parliament
Exemptions exist, but they're narrower than landlords assume
The current exemptions regime — inherited from the 2018 Minimum Energy Efficiency Standards rules and expected to carry through in similar form — allows a landlord to register an exemption where the “all improvements made” cap has been hit, where a relevant improvement isn't technically feasible for the property, or where a third-party consent (freeholder, planning, listed building) has been refused. What it does not cover is “I’d rather not spend the money” or “the tenant likes the current setup.” Listed buildings get particular scrutiny because conservation officers routinely block external wall insulation and uPVC replacement windows on heritage grounds — genuinely one of the few situations where the exemption is close to automatic, since you can't be required to do work your local authority won't permit.
Exemptions also expire. A five-year exemption registered in 2026 needs re-assessing in 2031, by which point cheaper technology or a change in circumstances may remove the justification — this isn't a one-time paperwork exercise that lets a property coast indefinitely below the standard.
What to actually do this quarter
Get an up-to-date EPC assessment before you do anything else, even if your current one isn't due for renewal — assessors vary in how generously they score existing insulation, and a poor initial assessment can overstate the work needed by two or three whole bands. Then get a retrofit assessment (PAS 2035, if the property qualifies for any grant funding) from a coordinator rather than going straight to an installer's sales quote, because installer-only surveys have an obvious incentive to recommend the product that installer sells.
If you own more than two or three sub-C properties, spreading the work across 2026 and 2027 rather than compressing it into 2028 is the better call — not just for cashflow, but because installer capacity is going to tighten hard as the deadline approaches and prices for both materials and labour will move with demand. Landlords who treat this as a 2027 problem are going to pay a premium that landlords who start now will avoid entirely.
None of this changes the maths for every property. A handful of pre-1900 solid-wall houses in conservation areas are going to sit in exemption limbo indefinitely, and a small number of landlords will conclude that selling to an owner-occupier — who faces no EPC C obligation at all — is genuinely the more sensible exit than a five-figure retrofit on a property that was never going to command a rent uplift to match. That's a legitimate answer. It just needs to be a deliberate one, made this year, rather than a default arrived at by ignoring the letter until 2029.