If you believe a development has breached a planning control you can contact your local planning authority.
A planning breach usually occurs when:
A planning breach in itself is not illegal and the council can permit a retrospective application where planning permission has not been sought.
However, if the breach involves a previously rejected development (or the retrospective application fails) the council can issue an enforcement notice.
In considering any enforcement action, the main issue for the local planning authority (LPA) should be whether the breach of control would unacceptably affect a public amenity. It is illegal to disobey an enforcement notice unless it is successfully appealed against.
The decisive issue for the LPA in considering any enforcement action should be whether the breach of control would unacceptably affect public amenity or the existing use of land and buildings meriting protection in the public interest.
Enforcement action should always be in proportion with the breach of planning control it is related to. For example, it is usually inappropriate to take formal enforcement action against a trivial or technical breach of control which causes no harm to an amenity in the site's area.
You can report a planning breach to your local council. It is the council's responsibility to organise how it enforces alleged breaches of planning control. How LPAs manage the administrative function and process of enforcing planning control is for each authority to decide.
When complaints about alleged breaches of planning control are received from members of the public or parish and community councils, they should always be properly recorded and investigated.
If the local planning authority decides to exercise its discretion not to take formal action following a complaint, it should explain its reasons to any organisation or person who has asked for an alleged breach to be investigated.