If you let commercial property in England or Wales, you cannot let a building rated F or G. The only way round it is a valid exemption. That is the rule today. The government also plans a higher bar of EPC B from 2031 for larger buildings. Solar can help a rating, yet how much depends on the building. So it needs modelling, not guesswork.
The rule today
Since 2018, the Minimum Energy Efficiency Standards (MEES) have sat in the government’s landlord guidance. Two dates matter:
- From 1 April 2018, a landlord may not grant a tenancy on a property rated F or G.
- From 1 April 2023, a landlord must not keep letting a property rated F or G.
The first check is simple, because the rating is public. Look up the EPC for each building and confirm it is E or better. If it is not, the landlord must raise the rating or register an exemption.
What happens if you get it wrong
Local weights and measures authorities enforce MEES, and the guidance sets two levels of maximum penalty:
- A breach of under three months: up to £5,000, or up to 10% of rateable value, with a cap of £50,000.
- A breach of three months or more: the greater of up to £10,000 or 20% of rateable value, with a cap of £150,000.
The authority can also publish details of the breach. That can hurt in a sale, a refinancing or a tenant’s checks, long before any fine is paid.
What the 2026 update says
While the rule is fixed for now, the government updated its response on the non-domestic MEES consultation. In summary:
- The idea of an EPC C milestone for 2027 will not go ahead.
- From 2031, it is proposed that private rented buildings over 1,000 square metres reach EPC B, where cost effective.
- Smaller buildings stay under the current EPC E standard.
- The seven-year payback test and exemptions stay in place.
- The change takes effect only after secondary legislation passes Parliament.
Read that with care. The 2031 date is a proposal, not yet law. Plan for it, but do not tell a tenant it is settled.
| Building size | Today | Proposed from 2031 |
|---|---|---|
| Up to 1,000 m² | EPC E | Stays EPC E |
| Over 1,000 m² | EPC E | EPC B, where cost effective |
The seven-year payback test
The guidance says a landlord must only fit a measure that pays back within seven years. A package of measures can pass even if one measure alone would not. This is the safety valve, yet it only works if you do the sums and keep the proof. Our glossary defines the terms used here.
Where solar fits
The guidance lists photovoltaics among the energy-saving improvements it recognises, although it gives no standard uplift. Non-domestic EPCs come from approved software. SBEM is one such tool. An accredited assessor can model a planned array and show the effect on your rating.
Two warnings apply, because solar is not a quick fix:
- There is no standard uplift. The result depends on array size against floor area, the heating system, and the building’s other energy use. A claim that solar “adds two bands” is a guess. Only an assessor’s re-run with your system in it gives a reliable figure.
- Other measures often do more. Lighting, controls, heating and insulation may give cheaper gains, so a good study ranks them all.
A rating gain is not the same as a payback gain. A system might lift an EPC and still pay back slowly on a leased building. That is because the landlord and tenant split the costs and the savings.
The landlord and tenant split
The landlord pays for the system, while the tenant may enjoy lower bills. Leases often ignore that. A landlord could share the benefit through a green lease clause. Another option is to charge the tenant for the power supplied. A third is a PPA, where a funder owns the system. Our guide to PPA, outright purchase and lease compares them. The guidance also warns that solar panels can need planning consent or other approvals, so check lease terms and lender rules.
Roof and building checks
Before you count on solar for a rating, confirm the roof can take it, since a weak roof ends the plan. Our article on roof surveys, structural loading and asbestos covers the checks. Commercial solar insurance covers the policy side. For offices and larger estates, see our commercial and offices and property developers pages.
Start with the numbers
Before you commit capital to an EPC target, find out what the building’s model shows with a set system in it. Check that the roof, structure and grid link allow it too. Our feasibility studies give an independent, site-specific answer. Then you decide on evidence, not a sales claim.
Solar is one of several ways to lift a rating, so test it against the others. A feasibility study checks the roof and the likely EPC effect, while our net zero strategy work places solar beside insulation and heating. Energy and ROI modelling shows the payback, and portfolio optimisation ranks which let buildings to treat first. For the wider carbon picture, read what net zero actually requires.