An appeal against planning permission is a formal objection to a planning decision made by a local authority. This can be done by an individual, group, or organization who believes that the decision is flawed or unreasonable.
There are a number of reasons why someone might want to appeal against planning permission. For example, they may believe that the development will have a negative impact on their property, the environment, or the local community. They may also believe that the planning process was not followed correctly, or that the decision was based on incorrect information.