As a landlord of a property rented on an Assured Shorthold Tenancy (AST) you are legally required to provide your tenants with an Energy Performance Certificate (EPC).
This certificate will show the energy efficiency of your property, as well as its environmental impact in terms of CO2 emissions. It's useful for your prospective tenants to have an idea of heating costs and forms part of a general government push to improve the energy efficiency of the UK's housing stock.