You can appeal a decision made by a local authority on a planning application if you disagree with it or if the application wasn’t determined within eight weeks (for a typical householder development) or 13 weeks for major developments.
The applicant of any type of planning application is usually entitled to appeal the decision of the local planning authority (LPA).
This is usually where an application is refused by the LPA, but there are also other rights of appeal in respect of other matters.
However, there are no third party rights of appeal - so if you have objected to a planning application and it is approved by the LPA then you cannot appeal that decision.
Only applicants or their appointed agents can appeal.