The Minimum Energy Efficiency Standard doesn’t mention conservatories by name — but if you’re a landlord, adding one to a property you let can still interact with your EPC obligations in ways worth checking before you build.

What MEES actually requires

The Minimum Energy Efficiency Standard (MEES) applies to domestic private rented properties in England and Wales that are let on an assured tenancy, a regulated tenancy or a domestic agricultural tenancy, and that are legally required to have an Energy Performance Certificate (EPC). Since 1 April 2020, landlords have not been able to let or continue letting a covered property with an EPC rating of F or G unless a valid exemption is registered. In practical terms, this sets a minimum EPC band of E as the baseline a rental property must meet, or the landlord must be relying on one of a defined set of exemptions.

Does building a conservatory trigger a new EPC?

An EPC is generally required whenever a property is built, sold or let, and government guidance notes that a property which has been materially modified in the past 10 years typically needs a current EPC before it can be marketed or let again. A conservatory is exactly the kind of change — added floor area, new glazing, a different roof structure — that can be considered a material modification. If you’re a landlord adding a conservatory to a property that’s currently let or about to be re-let, it’s worth checking with an accredited energy assessor whether your existing EPC is still valid for the property as it will stand once the work is finished, rather than assuming an EPC issued before the conservatory remains usable indefinitely.

How a conservatory can affect the rating itself

A conservatory itself is often excluded from a property’s heated floor area for EPC assessment purposes if it isn’t thermally separated from the rest of the house and isn’t heated by the main system — in which case it may have limited direct effect on the rating. But the position changes if the conservatory is integrated into the home’s heating system, if it replaces double doors with a large area of glazing that increases heat loss from the connecting wall, or if the assessor treats it as habitable space with its own heating provision. Because the effect depends on how the conservatory is built and used, a landlord planning one shouldn’t assume the outcome either way, and should treat the EPC impact as a genuine unknown to check rather than a formality.

Exemptions and the cost cap

If a property is rated below E, government guidance describes six categories of exemption a landlord can potentially register, including where all relevant energy efficiency improvements have already been made, where the cheapest recommended measure would cost more than the £3,500 (including VAT) cost cap for self-funded improvements, or where a listed building or similar consent constraint would be breached. Third-party funding, such as certain grant schemes, doesn’t count towards this £3,500 cap. Registered exemptions last five years before they need reviewing again, so an exemption in place when a conservatory was added isn’t necessarily still valid at the next check.

Penalties for getting it wrong

• Local authorities enforce MEES and can issue penalty notices for letting a non-compliant property without a valid exemption.
• Non-compliance for under three months can attract a fine of up to £2,000; longer non-compliance can attract a fine of up to £4,000, with a maximum combined penalty of £5,000 per property.
• A conservatory that unexpectedly drags a property’s rating down, or that triggers a need for a new EPC a landlord wasn’t aware of, can leave a property technically non-compliant without the landlord realising until a check is made.
• Getting an up-to-date EPC assessment after any significant alteration, rather than relying on the certificate that predates the work, is the straightforward way to avoid this.

FAQs

Does MEES apply if I live in the house myself?

No — MEES specifically applies to properties let under qualifying tenancies in the private rented sector. An owner-occupied home isn’t subject to these letting restrictions, though a good EPC rating can still matter for other reasons, such as a future sale or mortgage terms.

Will adding a conservatory automatically lower my EPC rating?

Not automatically — it depends on whether the conservatory is thermally separated from the main heating system and how it’s assessed. Get a professional assessment rather than assuming either outcome.

What’s the cost cap if I need to improve my property’s rating?

Landlords self-funding improvements are not currently required to spend more than £3,500 including VAT to reach compliance, though this figure and the wider MEES rules can be updated by government, so check the current position before budgeting.

Sources

This guide draws on the following primary sources, current as of 17 September 2026:

• GOV.UK: Domestic private rented property, Minimum Energy Efficiency Standard – landlord guidance

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Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not energy assessment or legal advice on any specific property — always confirm with an accredited assessor or your local authority.