When the planning committee of the local planning authority is determining a planning application, the planning officer will write a report on which the members of the committee will rely for information and guidance.

Decision makers have a statutory requirement to have regard to the development plan for the area and any other material considerations. Further, there is case law which requires that the decision maker must properly interpret the policy (EC Gransden v SSE 1987).

In R (on the application of Gibson) v Mid Sussex District Council [2014], the council granted permission for 26 houses on the edge of but outside a settlement limit. The relevant policy stated that such development should only be permitted in exceptional circumstances where there was no other suitable site to meet local need – a "rural exceptions" policy.

The officer's report mentioned the policy in general terms but did not draw members' attention to the need for an alternative sites assessment. The officer said in a statement to the court that alternative sites had been considered during the application process, although this was disputed by the claimant.

The claimant applied to the court to quash the decision to grant permission on the basis that the committee had failed to interpret the policy properly and had failed to take account of it. The court agreed. The members had been significantly misled by the report. Consideration of alternative sites by the officer was not consideration by the members. As the court was not satisfied that the committee would have reached the same decision if the report has been properly prepared, it quashed the decision. While the court has discretion not to quash a decision, it declined to exercise it in this case.

The moral of the story for local planning authorities is obvious. There is also a valid issue for developers – if the officer's report is obviously defective and is relied upon by the decision maker, then any grant of permission is vulnerable to challenge, with all the delays that brings.