The Government has now brought in a number of changes to planning enforcement practice, that were first passed into law in November 2023 under the Levelling Up and Regeneration Act 2023 (LURA). This Act allowed the Government to make certain changes but required the Secretary of State to pass secondary legislation to bring these changes into force. They include phasing out the '4 year rule' for changes of use to self-contained residential (Use Class C3) and new building works that do not benefit from express planning permission.
If you are a developer or investor who has changed the use of a building to a house or flats or undertaken building works without planning permission in either case, then you can apply to confirm that these changes are now lawful if they were done more than 4 years ago. However, when this law comes into force, you may need to prove 10 years continuous use or that the works were done at least 10 years' ago. You could therefore find yourself vulnerable to planning enforcement action for a longer period of time. Care should also be taken in the prospect of such action being taken against you if you acquire property that is not yet lawful.
The law comes into force from the 25th April 2024. It is not necessary to have obtained a lawful development certificate by this date in respect of the change of use or building works. However, if still seeking to rely on the 4 years' rule after this date when seeking a lawful development certificate, you will need to establish either 4 years' continuous use and occupation or that building works were 'substantially completed' at least 4 years' before (i.e. use started or building works were completed no later than 24th April 2020).
Therefore, if your building was extended or built or its use changed more recently than 24th April 2020, you will likely be subject to the need for 10 years' proof and, if detected by the local planning authority, there is a risk of either enforcement action against you or the need to apply for retrospective planning permission.
These changes apply only to England, as the 4 year rule is retained in Wales.
