Energy rules for commercial buildings have quietly become one of the most important things a small business landlord or occupier needs to understand. The two terms you will keep hearing are EPC and MEES. They sound like jargon, but the practical effect is simple: an inefficient building can become harder to let, and it almost always costs more to run.
This guide explains what both terms mean, who is affected, the rules that apply today, the direction of travel for 2031, and the sensible steps you can take now. Win Energy is an energy broker, not an EPC assessor, so we will be clear about where our help ends and where a qualified assessor or surveyor takes over.
What is an EPC?
An Energy Performance Certificate rates how energy efficient a building is, on a scale from A (best) to G (worst). It also sets out recommendations for improvement. Every commercial property that is let generally needs a valid EPC, and the rating sits at the centre of the wider rules.
An EPC is produced by an accredited assessor who looks at how the building is constructed and serviced: the fabric, insulation, lighting, heating and controls. It is a snapshot of the building's designed efficiency, and it is the number that landlords, tenants and lenders increasingly look at first.
What is MEES?
MEES stands for Minimum Energy Efficiency Standards. These are the rules that turn the EPC rating from a piece of paper into something with legal teeth. In short, MEES sets a minimum EPC rating below which a landlord may not lawfully let a commercial property.
Since April 2023 it has been unlawful for a landlord to grant a new lease or continue an existing let of a commercial property with an EPC rating of F or G, unless a valid exemption is registered. This is the rule in force today.
The phrase "continue to let" matters. This is not only about new leases. A landlord already letting an F or G rated property needs to either improve it or register a valid exemption. Exemptions exist for specific situations, but they must be registered properly rather than simply assumed.
Who is actually affected?
Three groups should pay attention:
- Landlords letting commercial space. You carry the primary legal responsibility under MEES. A poor rating can restrict your ability to let and can reduce the value of the asset.
- Tenants and occupiers. You may not hold the legal duty, but the building's efficiency directly affects your energy bills. A draughty, poorly lit, badly heated unit costs more to run every single month. Efficiency is also increasingly written into lease negotiations.
- Small commercial landlords and owner-occupiers. If you own the building your business trades from, you sit on both sides of the issue and stand to benefit most from getting it right.
The direction of travel: EPC B by 2031
The rules are set to tighten. In a June 2026 update, the Government confirmed the direction of travel for commercial property.
- From 2031, commercial buildings above 1,000 square metres are expected to reach at least EPC B, subject to exemptions.
- Commercial property below 1,000 square metres will need at least EPC E, subject to exemptions.
There is also welcome news on timing. The previously proposed interim milestone of EPC C by 2027 has been dropped and will not be taken forward. That gives landlords more breathing room to plan improvements sensibly rather than in a rush.
One important caveat: these future changes still require secondary legislation to pass through Parliament before they take legal effect. Treat the 2031 EPC B target as the clear direction of travel, not a settled certainty. The exact final detail may shift.
Practical steps to take now
You do not need to overhaul everything overnight. A measured plan is far more effective than panic.
- Get or refresh your EPC. Find your current certificate and check the rating and expiry date. If it is old, out of date, or you have made changes to the building, commission a new assessment from an accredited assessor. You cannot plan without knowing your starting point.
- Read the recommendations. Every EPC comes with suggested improvements. This is your ready-made shortlist, often ranked by impact.
- Plan efficiency improvements. Improving an EPC typically involves better lighting (switching to LED), upgrading heating and controls, adding insulation, and sometimes on-site generation such as solar panels. Many of these also cut day-to-day running costs, so they pay you back twice.
- Register any exemption correctly. If your property genuinely qualifies for an exemption, make sure it is registered properly rather than assumed.
- Get the energy contract right. A more efficient building uses less energy; the right contract makes sure you pay a fair price for what you do use. Both levers cut your bills.
Where Win Energy fits in
We are an independent business energy broker, not an EPC assessor. We cannot issue your certificate or carry out the building survey. What we can do is help with the part we know well: getting your business onto a competitive, and where you want it, greener energy contract, and thinking through how your building uses energy.
How a building actually uses energy affects its running costs just as much as its rating. A better building and a better contract work together. If you would like to review your business electricity or business gas arrangements while you plan your efficiency work, our service is free and we are paid by commission from the supplier you choose. That is the whole model, and we are happy to be plain about it.
MEES and EPCs are not something to fear. They reward exactly the kind of improvements that make a building cheaper and more pleasant to occupy. Understand your rating, make a sensible plan, and get the contract right. If you want a hand with the energy side, get in touch and we will talk it through honestly.