The Town and Country Planning (General Permitted Development) Order 2015 grants an effective nationwide planning permission for various minor forms of development. This is know as "permitted development". The Order restricts some permitted development rights more tightly in Conservation Areas. In addition planning authorities have the power to remove further permitted development rights by issuing what is known as an Article 4 Direction. Article 4 Directions can be made on any land within a planning authority's area, not just in Conservation Areas, but they are more likely to be imposed in Conservation Areas. When a planning authority makes an Article 4 Direction, it has to notify all owners of land or buildings in the area.
Article 4 Directions can only apply to development which is proposed - they cannot apply to development which has been completed or is in progress.
Before undertaking any development, check with your Planning Department to see if any restrictions on permitted development have been made. In addition to Article 4 Directions, sometimes conditions on a planning permission that has been granted in the past can take away rights to carry out permitted development.
It is important to remember that the removal of permitted development rights does not mean that you (or anyone else) will not be allowed to make changes to your property. A planning application has to be made for it in the usual way. If a proposal only requires planning permission because of an Article 4 Direction or a condition on a planning permission, no fee is payable for the application.