Article four directives came into effect at the beginning of October and give councils the ability to remove permitted development rights from a specific area, meaning owners would have to apply for planning permission and legal forms to change their property.
Simon Smith, chief executive of Betternest, said that the reform means current development rights could evaporate within a year.
"At the moment most people don't even know what permitted development rights are, most people don't know what the reform is and they certainly don't know what article directives are," he added.
Mr Smith added that local authorities would welcome the legal reform, as they "do not like permitted development".
According to Planning Portal, a permitted development right is the ability to make minor changes to property without planning permission and is derived from Parliamentary planning permission, not from local authorities.
