Every let home in England needs an energy performance certificate, and since 2020 it must rate at least Band E. From 1 October 2030 the minimum energy standard becomes the equivalent of Band C, which most period London flats do not meet. For a Gulf owner whose stucco conversion rates D, that is several thousand pounds and a decision about when to spend it. It sits alongside our guide on letting and managing from the Gulf.
Owning and letting
EPC and the minimum energy standard: what a let London flat must reach now, what it must reach by October 2030, and what it costs
What an EPC is and how the energy rating works
A let flat in England must rate EPC E or better, with a £3,500 cost cap and a penalty of up to £5,000 for letting an F or G. From 1 October 2030 every privately rented home must meet the equivalent of EPC C, with a £10,000 cap and ten-year exemptions. About a third of our clients’ flats are already C and half are D. A D-rated conversion usually reaches C for £6,000 to £12,000; an E-rated flat may need wall insulation and exceed the cap.
An energy performance certificate is a ten-year assessment by an accredited assessor of a home’s energy efficiency, rated A (best) to G, from a model of the building’s fabric, heating, lighting and hot water; it costs £60 to £120 and is required on sale and on letting. The rating is of the dwelling, not of how the occupier uses it, and it rewards insulation, double glazing, efficient boilers and low-energy lighting.
EPC public register and the reformed energy certificate from 2026
The certificate is on the public register, and the letting agent must show it to prospective tenants. From 2026 a reformed certificate is being introduced with several metrics (fabric, heating system, smart readiness, cost) rather than one rating, and the 2030 standard is written in those terms.
Current minimum EPC standard for let flats in England and Wales
A let dwelling in England and Wales must have an EPC rating of E or better, unless a valid exemption is registered. A landlord who lets an F- or G-rated property faces a civil penalty from the council of up to £5,000 per property, and the Renters’ Rights Act’s database will make non-compliance visible. The cost cap for the current standard is £3,500 including VAT: a landlord who cannot reach E for that sum makes the improvements that can be made within it and registers a “high cost” exemption for five years. Most London flats already meet E; the standard that matters is the next one.
EPC C standard for privately rented homes from October 2030
The government’s decision of 21 January 2026, following consultation, is that from 1 October 2030 all privately rented homes in England and Wales must meet a standard equivalent to EPC C, with a single compliance date for new and existing tenancies. The standard is in two parts under the reformed certificate: a fabric performance standard that every home must meet, then a choice of a heating system standard or a smart readiness standard.
2030 EPC cost cap, exemptions and timing for landlords
A home with a current certificate rated C or better remains compliant until that certificate expires. The cost cap rises to £10,000; exemptions are widened and last ten years; short-term lets are excluded. The legislation is to be made by 2027, which leaves the detail to come and the direction settled. Our guide on sell or hold includes this cost in the arithmetic.
How London flats typically score on EPC ratings
A new tower flat: B or C, compliant. A 1930s mansion block flat with double glazing and a modern boiler: D, sometimes C. A stucco or Victorian conversion with single-glazed sashes, solid walls and an old boiler: D or E, and the worst of them F. A house: D to E typically.
EPC ratings we see across our clients' London flats
The firm’s experience across clients’ flats is that about a third are already C, half are D, and the rest are E or need an exemption; the D-rated flats are the ones to plan for, because the works that lift a D to a C are usually within the £10,000 cap, and the works that lift an E are not always.
Energy improvement works that raise an EPC rating
The measures that lift a rating, with indicative London costs:
Energy improvement works and typical London costs, 2026
| Measure | Typical cost on a London flat | Rating effect |
|---|---|---|
| LED lighting throughout | £200 to £500 | small |
| Loft insulation (top-floor flats and houses) | £500 to £1,500 | medium to large |
| Modern condensing boiler and controls | £3,000 to £5,000 | medium |
| Secondary glazing on sash windows (conservation areas will not permit replacement in most cases) | £3,000 to £8,000 | medium |
| Double-glazed sashes where permitted | £8,000 to £20,000 | medium |
| Internal wall insulation on solid walls | £8,000 to £15,000, and disruptive | large |
| Heat pump in place of a gas boiler | £8,000 to £15,000, where the block and the lease permit | large under the heating metric |
| Smart heating controls, smart meter | £300 to £800 | counts under the smart readiness metric |
Source: firm’s indicative London works costs, October 2026; rating effects under GOV.UK minimum energy efficiency standard guidance.
A D-rated conversion flat usually reaches C with lighting, a new boiler, controls and secondary glazing, for £6,000 to £12,000; an E-rated one may need wall insulation and exceed the cap. The assessor can run the model before the work is done and say which measures reach C, which is the first £150 to spend.
Leasehold complications when improving a London flat's EPC
Most works touch the building: windows (often the freeholder’s or subject to the lease’s alteration covenant), external walls, the roof and loft space, and the heating system in a block with communal heating.
Freeholder consent for energy improvement works in leasehold blocks
The leaseholder needs the freeholder’s consent, which cannot be unreasonably withheld for improvements of this kind but takes months and fees; a conservation area and a listed building limit what can be done to windows at all; and a block-wide measure (insulating the roof, replacing a communal boiler) is the freeholder’s to do and the service charge’s to pay, as our guide on service charges explains.
A landlord who cannot obtain consent registers a third-party-consent exemption. The sensible approach is for the block’s leaseholders to press the managing agent for a building-wide plan now, because 2030 will arrive for every flat in the block at once.
Exemptions and penalties
Exemptions, registered on the national register: all relevant improvements made within the cap; high cost; wall insulation that would damage the fabric; third-party consent refused; devaluation by more than 5 per cent certified by a surveyor; and a six-month exemption for a new landlord. Under the 2030 regime exemptions last ten years and are to be widened.
EPC penalties under the current and 2030 regimes
Penalties under the current regime are up to £5,000 per property; the 2030 regime’s penalties are not yet set but the government has signalled higher figures. A landlord abroad relies on the agent to keep the certificate current and the exemption registered, and our guide on choosing an agent includes it in the questions.
A year-by-year plan to reach EPC C by 2030
This year: obtain the current certificate and the assessor’s list of measures that would reach C. Next year: do the cheap measures (lighting, controls, boiler if due) and write to the freeholder about windows and the roof. By 2028: decide whether the flat reaches C within £10,000 or needs an exemption, and budget accordingly.
By 2029: complete the works while contractors are available and before every landlord in London wants the same ones; the firm expects prices for secondary glazing and insulation to rise sharply in 2029 and 2030. For a flat that cannot reach C economically, the decision is the one in our sell-or-hold guide, and 2027 to 2028 is the time to make it.
Sources: Domestic private rented property: minimum energy efficiency standard (GOV.UK) · Improving the energy performance of privately rented homes: consultation outcome (GOV.UK, January 2026) · Find an energy certificate (GOV.UK). Checked against GOV.UK on 14 October 2026: the domestic minimum energy efficiency standard guidance (Band E, £3,500 cap, exemptions, penalties) and the government’s response of 21 January 2026 to the consultation on improving the energy performance of privately rented homes (EPC C equivalent by 1 October 2030, £10,000 cap, ten-year exemptions). Works costs are indicative London figures. General information, not advice on a particular property. Figures verified 14 October 2026.
Frequently Asked
Questions about EPC and the 2030 energy standard
No; D is compliant until October 2030. You should find out this year what it would take to reach C, because the answer decides your spending over the next four years.
Not automatically; listed buildings need an EPC when let and must meet the standard where the works would not unacceptably alter their character, with an exemption where they would. An assessor and the council’s conservation officer decide.
No; the 2030 standard requires the fabric standard plus either a heating system standard or a smart readiness standard, and a flat with an efficient gas boiler and smart controls can meet it.
An energy performance certificate costs £60 to £120, lasts ten years and is required on sale and on letting. It is prepared by an accredited assessor from a model of the building’s fabric, heating, lighting and hot water, rated A to G. The certificate sits on the public register and the letting agent must show it to prospective tenants.
A civil penalty from the council of up to £5,000 per property under the current regime, and the Renters’ Rights Act’s database will make non-compliance visible. The 2030 regime’s penalties are not yet set, but the government has signalled higher figures. A landlord abroad relies on the agent to keep the certificate current and any exemption registered.
A D-rated conversion flat usually reaches C with lighting, a new boiler, controls and secondary glazing, for £6,000 to £12,000, which is within the £10,000 cap in most cases. An E-rated flat may need internal wall insulation at £8,000 to £15,000 and exceed the cap. The assessor can run the model before any work is done and say which measures reach C; that is the first £150 to spend.
Consent cannot be unreasonably withheld for improvements of this kind, but obtaining it takes months and fees. A landlord who cannot obtain consent registers a third-party-consent exemption. Block-wide measures such as insulating the roof or replacing a communal boiler are the freeholder’s to do and the service charge’s to pay, so leaseholders should press the managing agent for a building-wide plan now.
Yes. A home with a current certificate rated C or better remains compliant until that certificate expires, even though the 2030 standard is written in the terms of the reformed certificate with its fabric, heating and smart readiness metrics. A certificate lasts ten years.
On the national register: all relevant improvements made within the cap; high cost; wall insulation that would damage the fabric; third-party consent refused; devaluation by more than 5 per cent certified by a surveyor; and a six-month exemption for a new landlord. Current exemptions last five years. Under the 2030 regime they last ten years and are to be widened, and short-term lets are excluded from the standard.
