If you let commercial property in England or Wales, the Minimum Energy Efficiency Standards (MEES) regime is the single piece of regulation most likely to disrupt your portfolio over the next two years. The 2027 tightening to EPC C, while not yet in force, is on every serious landlord's capex plan and is already shaping leasing decisions.
This guide explains what is currently law, what is still consultation, and what a London commercial landlord can sensibly do in the next 12 months to stay ahead of it.
Where MEES sits today: the current sub-E prohibition
Under the Energy Efficiency (Private Rented Property) (England and Wales) Regulations 2015 (SI 2015/962), it has been unlawful since 1 April 2018 to grant a new commercial lease, or extend an existing one, on property rated F or G. From 1 April 2023, that prohibition was extended to all continuing commercial leases regardless of when the tenancy started.
The penalties are significant. For a breach of less than three months, the financial penalty is the greater of £5,000 or 10% of rateable value, capped at £50,000. For a breach of three months or more, it rises to the greater of £10,000 or 20% of rateable value, capped at £150,000 per property. A separate publication penalty also applies, naming the landlord on the public PRS Exemptions Register.
For most London landlords with reasonably modern stock this is no longer a live problem. The compliance challenge has shifted to the next threshold.
What's proposed for 2027 and 2030
The previous government consulted on raising the minimum commercial EPC rating to C from 1 April 2027 and to B from 1 April 2030. The current administration has signalled intent to legislate but, as of mid-2026, no statutory instrument is in force for either threshold. Treat C-by-2027 and B-by-2030 as 'highly likely' rather than 'definite' for legal-risk purposes, but plan capex on the assumption they will land.
The reason most experienced landlords aren't waiting for the SI: lead times. A non-trivial MEES improvement plan, especially in older Central London office stock, can run 12 to 24 months from initial EPC re-rating to completed works and re-lodgement. If 2027 is the target, the conversation needs to happen in 2026.
What an EPC C uplift actually involves
The route from D or E to C depends almost entirely on the building. For a 1980s air-conditioned office, the typical path is: replace remaining gas-fired heating with electric heat pumps, upgrade lighting to fully controlled LED, install a modern BMS, and address any single-glazed sections. For converted Victorian or Edwardian commercial stock common across Camden, Islington and Westminster, listed-building constraints often rule out external fabric upgrades, so the lift comes from services, controls and renewables.
The least helpful approach is to treat MEES as a binary EPC pass/fail exercise. The most useful approach is to model your stock against both the current sub-E rule and the proposed C and B thresholds, and prioritise capex toward the buildings that are MEES-critical and lease-critical.
Exemptions you can register today
If genuinely cost-effective improvements still leave a property below E, you can register an exemption on the PRS Exemptions Register. The most-used exemption is the seven-year payback rule: if all relevant improvements that could be made do not pay back through energy savings within seven years, you can register a five-year exemption supported by three contractor quotations and an assessor's calculation.
Other exemptions include the consent exemption (where a tenant or planning authority has refused consent for the works), the devaluation exemption (where works would reduce the property's market value by more than 5%), and the new landlord exemption (a six-month grace period on becoming the landlord). Each requires specific evidence; none allow the property to remain non-compliant indefinitely.
Practical 12-month plan for a London landlord
Step one: get a current EPC on every property. Many landlords are still relying on certificates lodged in 2014 or 2015 against the old SBEM 4.x calculation methodology. Re-rating against the current methodology often shifts a property by a band, in either direction.
Step two: build a portfolio gap analysis showing the rating, lease expiry date, and indicative cost-to-C for each asset. Properties with a long lease expiry and an expensive cost-to-C should be queued for early intervention; short-lease low-rated stock might be candidates for refurbishment between tenancies rather than mid-term.
Step three: where C looks expensive or impossible, model the seven-year payback exemption now so you have evidence in the file when enforcement officers ask.
Need an EPC or MEES audit on your London commercial stock?
Accredited assessors, lodged on Landmark in 24-48 hours. 1,000+ certificates delivered across Greater London.