If you are a landlord, you will be aware that you must have EPCs (Energy Performance Certificates) on your rental properties before renting them out.

EPCs show the energy efficiency of a building and help identify ways to improve it. This applies to both residential and commercial properties. You will probably have considered this to be a bit of EU bureaucracy that needs to be complied with but can then be ignored.

The underlying reason for EPCs is that buildings are a major source of the UK's greenhouse gas emissions. In 2009, domestic buildings were responsible for 25 per cent, and non-domestic buildings were responsible for 12 per cent, of the UK's total emissions.

The introduction of minimum energy efficiency standards on April 1 will change how landlords deal with EPCs. After this date, landlords must ensure their domestic and non-domestic privately rented property reach minimum energy efficiency standards before they can be let. The regulations state that if your EPC is lower than E, subject to exemptions, it will become illegal to:

• grant a new tenancy or renew an existing tenancy of a private rented property

• continue to let a domestic private property after April 1, 2020

• continue to let a non-domestic private rented property after April 1, 2023

The detailed rules are very complex and some buildings are exempt. Watford landlords should check what rating their building EPCs are. If you need to carry out remedial work to improve the rating, plan this as soon as possible. A sub-standard EPC rating may seriously affect your ability to let a property and as such the income stream deriving from it.

- David Marsden is a partner at award-winning Watford-based law firm VWV