MEES and the commercial EPC standard

The minimum energy efficiency standard comes from the Energy Efficiency (Private Rented Property) (England and Wales) Regulations 2015. It works by fixing a floor under the EPC rating of let property. Below that floor, letting is unlawful unless you have registered a valid exemption.

For non domestic property the floor is band E. New lettings below band E became unlawful on 1 April 2018. Continuing to let a building that was already let and sits below band E became unlawful on 1 April 2023. That second date is the one that catches people, because it applies to standing tenancies where nothing has changed and nobody has signed anything.

The certificate is a modelled result, not a measurement. It reflects the fabric, the plant and the services of the building against a standard pattern of use. That is why a building with a poor band can have a low bill, and why a building with a good band can still be expensive to run. Both facts are true at once and both matter, for different reasons.

Two things are worth separating here. What is law today, and what is confirmed policy direction that still needs secondary legislation before it binds anybody.

The practical point is that a band E building is not comfortable. It is one assessment away from a problem, and the work to move it takes months to specify, price and deliver. If you are planning around a lease event, count backwards from that date.

Enforcement sits with the local authority. Penalties are civil and they are calculated from the rateable value of the property, which is why they scale with the size of the building rather than with the cost of the work you avoided. They can reach £150,000 per property, with a higher band applying where the breach has continued for three months or more.

There is a second penalty that costs nothing and hurts more. A breach can be published on the public register, where anybody can find it, including your tenants, your lender and the next party you try to let to.

In practice the commercial consequence usually arrives before the enforcement does. A building you cannot lawfully let has no income, and the position surfaces at a lease event when a solicitor asks for the certificate. At that point the work becomes a negotiation conducted at speed with somebody who knows you have no alternative. That is the expensive version of this problem, and it is entirely avoidable by knowing your bands in advance.

An exemption is not something you decide you have. It has to be registered on the private rented sector exemptions register, with the evidence the regulations require, and it is time limited. An unregistered exemption is simply a breach with an explanation.

Most exemptions last five years and the recent landlord one is much shorter. Nothing rolls over. When one expires you either do the work or requalify with fresh evidence, and the costs and the payback tests will have moved by then. Diary the expiry dates alongside your certificate expiry dates.

Only measures that are modelled into a non domestic assessment change the band. That is a narrower list than the list of things worth doing, and it is worth being clear about the difference before you spend money expecting a rating movement.

How far each one moves your building depends on where the modelled result currently sits. A building close to a band boundary can cross it with a lighting retrofit alone. A building deep inside a low band usually needs fabric and plant together. Anybody who quotes you a band improvement without modelling your specific building is guessing.

• LED lightingLighting is modelled directly and is usually the cheapest way to move a band. It is also the least disruptive work in the list.
• InsulationFabric is a direct input. On older stock with a poor roof it can be decisive, and it improves every heating measure that follows.
• Heat pumpsChanging the heating fuel changes the modelled carbon and energy use, often by a large margin. Cost and electrical capacity are the constraints.
• Boiler replacementPlant efficiency is modelled, so a new condensing boiler with proper controls moves the result, though less than electrifying the heat.
• Solar panelsOn site generation reduces the modelled energy use. Rarely the cheapest route to a band on its own, but it comes free on a building having solar anyway.

Measures that do not move a band include battery storage, EV charging and voltage optimisation. They can all be worth doing. They will not help with this.

A non domestic certificate is produced by an accredited assessor who surveys the building and builds a model of it. They record the construction and insulation, the glazing, the heating and cooling plant and its fuel, the ventilation, the lighting and its controls, the hot water, and any on site generation. The model then runs a standard pattern of use against that description.

Because it is a model, evidence changes the answer. Where the assessor cannot see or confirm something, they must assume the default, and defaults are conservative. Drawings, specifications, product data sheets and commissioning certificates for plant and lighting can move a rating without a single change to the building. Gather them before the visit.

A certificate lasts ten years, but the rules apply to the building rather than to the paperwork. If your certificate is old and the building has changed, ask for an indicative assessment before commissioning a new one. A new certificate supersedes the old one, so finding out that the band has fallen is much better done before it is lodged.

The recommendation report that comes with the certificate is generic and it is not a specification. Treat it as a prompt, not a plan.

Fees are quoted per building and are not standard. What moves them is floor area, the number of separately serviced zones, how many heating and cooling systems are involved, how much of the building the assessor has to survey rather than read from drawings, and whether the unit has been subdivided. A single let warehouse is at the cheap end. A subdivided office with mixed plant and no drawings is at the expensive end, and the survey itself takes longer. We do not quote assessment fees, so get two or three from accredited assessors and compare what each one includes, particularly whether an indicative result is given before the certificate is lodged.

If you let buildings, our page on what to do when you let the building out covers who pays, how recovery works and what to do about a tenant who benefits from work you fund.

Add your buildings and we will show the band on each, when the certificate expires, and which measures would move it, with costs and savings as ranges.

This page explains the regime in general terms. It is not legal advice on a specific building or lease.