An F or G EPC rating is the lowest two bands on the energy performance scale. For sellers, it can suppress your property’s value and deter buyers. For landlords, it is much more serious — in most cases it is illegal to let a property with an F or G rating, and the financial penalties are substantial.

This guide explains exactly what the law requires, what the fines are, where the exemptions sit, and — most importantly — what practical steps you can take to resolve the situation quickly. Our team at EPC Rate carries out assessments and reassessments across London every day, and we see F and G-rated properties regularly. Here is what you need to know.

What an F or G rating actually means

The Energy Performance Certificate uses the government’s Standard Assessment Procedure (SAP) to calculate a score from 1 to 100. An F rating covers SAP scores of 21–38; a G rating covers 1–20. These are the two lowest categories on the scale, indicating a property that is poorly insulated, difficult and expensive to heat, and a significant contributor to carbon emissions.

Common characteristics of F and G-rated properties include solid walls with no insulation, single-glazed windows, an old inefficient boiler or no central heating at all, uninsulated lofts, and no meaningful heating controls. Many pre-1920 London properties — particularly older Victorian terraces — fall into these bands without remedial work.

“An F or G rating is not a minor inconvenience — it is a legal liability for landlords and a serious deterrent for buyers and tenants. In most cases it is also a sign of genuinely poor living conditions: cold, damp, and expensive to run.” — EPC Rate senior assessor, East London

The SAP score also drives a separate metric: the Environmental Impact Rating, which measures CO₂ emissions. Properties rated F or G on the energy scale are almost always rated equivalently poorly on the environmental scale. Both ratings appear on the EPC certificate.

Legal consequences for landlords

The Minimum Energy Efficiency Standards (MEES) regulations, which came into force in England and Wales on 1 April 2018 for new tenancies and 1 April 2020 for all existing tenancies, make it unlawful to let a domestic property with an EPC rating below E.

This means that if your property is rated F or G, you are — in most cases — currently in breach of the law if you have a tenant in occupation or if you attempt to grant a new tenancy. The only lawful routes are:

• ✓ Carry out improvement works to raise the rating to at least E before letting
• ✓ Register a valid exemption on the PRS Exemptions Register
• ✕ Continue letting without either — this is unlawful and subject to enforcement

Enforcement is carried out by local authorities. If a tenant complains, a neighbour reports a property, or a routine check by the local housing team flags an issue, the landlord can face investigation, formal notice, and ultimately financial penalties.

The fine structure — how much you could owe

Fines for MEES breaches are calculated based on the rateable value of the property and the length of time the breach has been in place. The penalty structure is as follows:

It is also worth noting that penalty notices are published on the PRS Exemptions Register, which is publicly searchable. This means fines become part of the public record — visible to future tenants, lenders, and buyers — in addition to the financial impact.

Does an F or G rating affect selling?

There is currently no legal prohibition on selling a property with an F or G EPC rating. You are required to have a valid EPC before marketing a property for sale, and that certificate must be made available to prospective buyers — but the rating itself does not prevent a sale from completing.

The practical impact, however, is significant:

• ✕ Buy-to-let investors will typically walk away, as the property is unlettable without remediation
• ✕ Some mortgage lenders apply restrictions or surcharges on F and G-rated properties
• ✕ Buyers may negotiate heavily on price, citing the cost of required improvements
• ! Owner-occupier buyers may proceed — but will factor energy costs and improvement works into their offer
• ✓ The certificate must still be displayed and provided to all prospective buyers

In practice, a property with an F or G rating can sell — but it will typically sell for less, take longer to sell, and attract a narrower pool of buyers. If you are planning to sell, having improvement works carried out before going to market — and booking a reassessment with EPC Rate to get an updated certificate — will almost always improve both the saleability and the sale price.

Exemptions — when the rules don’t apply

There are specific circumstances in which a landlord can legally continue to let a property rated below E, provided they register a valid exemption on the government’s PRS Exemptions Register. Exemptions are not automatic — they must be actively applied for, documented, and registered.

The seven-year payback exemption

If the cheapest improvement measure identified on the EPC recommendation report would cost more than £3,500 to implement, and there are no other cost-effective measures available under that threshold, a landlord may register a “high cost” exemption. This exemption lasts five years before it must be reviewed.

Third-party consent exemption

If improvements cannot be made because necessary consent from a third party — typically a freeholder, head leaseholder, or local planning authority — has been refused or is not forthcoming despite reasonable efforts, a landlord may register this exemption. It requires documented evidence of the refusal.

Property devaluation exemption

If an independent RICS surveyor certifies in writing that the proposed improvement measures would reduce the market value of the property by more than 5%, an exemption may be registered.

New landlord exemption

Landlords who become landlords through inheritance or unexpected circumstances (rather than a deliberate investment decision) may register a temporary exemption of six months to allow time to bring the property up to standard.

What tenants can do

Tenants living in F or G-rated properties have rights under MEES. Specifically, a tenant can submit a written request to their landlord asking them to carry out energy efficiency improvements. Once this request is made, the landlord has an obligation to respond and to bring the property up to at least band E — unless a valid exemption has been registered.

• ✓ Tenants can request improvements in writing at any time
• ✓ Landlords cannot evict tenants in retaliation for making such a request
• ✓ Tenants can report non-compliant landlords to the local authority
• ✓ Local authorities can issue improvement notices and ultimately enforce remediation

Tenants should also be aware that an F or G-rated property is likely to be cold, damp, and expensive to heat. If the property has damp or condensation issues related to poor insulation and ventilation, there may be additional routes under the Housing Health and Safety Rating System (HHSRS).

The 2028 rule change — what’s coming

The current minimum standard of band E has been in place since 2020. The government’s proposed trajectory is to raise the minimum to band C for new tenancies from 2028, with all existing tenancies to follow by 2030. While these dates have been subject to political discussion and the precise regulatory implementation is still being confirmed, the direction of travel is clear.

For landlords currently holding F or G-rated properties, this means two things:

• ✕ Reaching band E is not the end — band C will become the target within two years
• ✓ Improvement work done now to reach E can be built upon to reach C — making early action far more cost-efficient than two separate rounds of work

What to do right now

If your property is currently rated F or G, here is the order of action we recommend based on assessments carried out across London: