# How long a commercial EPC lasts and when to get a new one > Why a valid commercial EPC can still be the wrong one, and when a reassessment is worth paying for before the old one expires. Source: https://commercialepcupgrades.co.uk/how-long-does-a-commercial-epc-last --- # How long a commercial EPC lasts and when to get a new one A commercial EPC has a fixed life, and the useful question is not when it expires. It is whether the one you have still describes the building you own. Certificates do not update themselves, so a building that has been improved since it was assessed carries a certificate that is simultaneously valid and wrong. General guidance, not legal advice Energy performance rules for commercial property in England and Wales have changed repeatedly, and proposals have moved during consultation. This page describes the position as we understand it and is written to be useful rather than definitive. Check the current position and your own obligations with a solicitor or a qualified assessor before committing to capital spend. ## Valid and wrong at the same time Change the lighting, replace the boiler, insulate the roof, and the certificate on the register says exactly what it said before. It remains valid. It also now understates the building, in public, to anyone who looks it up. That matters at precisely the moments a certificate matters: a letting, a sale, a refinance, a MEES question. Paying to reassess a building you have improved is usually the cheapest part of the whole improvement project, and it is the step most often forgotten once the contractor has left. ## When to reassess early - After any meaningful improvement works, as the final step of the project rather than an afterthought. - Before marketing the property for sale or letting, so the public record reflects the building accurately. - Before a lender or investor looks at it, for the same reason. - Where the current certificate was produced with poor access or missing documentation, and defaults were applied that you can now evidence away. - Where the building has changed use or been subdivided, because the assessment basis may no longer match the property as let. ## The methodology moves too The modelling methodology and the factors inside it are updated periodically. That means the same unchanged building can produce a different rating when it is reassessed, in either direction, without anything physical having happened. It is a reason not to assume a reassessment will confirm what you expect, and a reason to model before committing capital on the basis of an old certificate. ## Subdivision is the quiet trap A certificate covers the property as assessed. Split a unit into two, or combine two into one, and what is on the register may no longer correspond to what you are letting. That is a problem that surfaces at the letting, which is the worst moment to discover it. If the demise has changed, the certificate position needs checking before the property is marketed. ## Questions we get asked ### How long is a commercial EPC valid for? ### Do I need a new EPC after improvement works? ### Can the rating change without changing the building? ### What if I have split or combined units? Sources - A non-domestic EPC is an asset rating: it is based on the fabric of the building and its services rather than on metered consumption. [A guide to energy performance certificates for the construction, sale and let of non-dwellings, DCLG, 2014](https://www.gov.uk/government/publications/energy-performance-certificates-for-the-construction-sale-and-let-of-non-dwellings) Last updated 8 October 2026 . - [What happens in an assessment What a reassessment involves](https://commercialepcupgrades.co.uk/non-domestic-epc-assessment) - [Selling a property Where an out-of-date certificate costs you](https://commercialepcupgrades.co.uk/commercial-epc-when-selling) Next step ## Find out where your buildings actually sit Before you plan against a deadline it helps to know the gap. Tell us the building and one commercial contractor comes back with what it would take to close it. Or call [07367 293494](tel:+447367293494). Monday to Friday, 9am to 5.30pm.