The Top 5 Reasons Planning Applications Are Refused

Waiting eight weeks for a planning decision only to receive a refusal is incredibly frustrating. It wastes time, money, and delays your project. But refusals are rarely random. Local planning authorities assess applications against strict local and national policies.

By understanding the most common pitfalls, you can dramatically increase your chances of a first-time approval.

1. Overdevelopment of the Plot

Councils want to ensure that a property doesn’t look cramped on its plot. If your proposed extension takes up more than 50% of the garden, or pushes right up to the boundary leaving no breathing space, it will likely be refused as "overdevelopment."

2. Loss of Light or Overshadowing

Your extension must not unfairly plunge your neighbours into darkness. Planners use the "45-degree rule" to assess this. If your extension breaks a 45-degree line drawn from the centre of your neighbour’s nearest habitable room window, you’ll face strong opposition.

3. Out of Character with the Local Area

Your design doesn't have to be a carbon copy of the house next door, but it must respect the "street scene" and local vernacular. A hyper-modern, zinc-clad box extension might look stunning on paper, but if it's attached to a row of traditional Victorian terraces, it may be rejected for being visually incongruous.

4. Overlooking and Loss of Privacy

Balconies, roof terraces, and side-facing windows are notoriously difficult to get approved if they allow you to peer into your neighbour’s private garden or windows. If you include these features, you must mitigate the impact using obscured glazing or privacy screens.

5. Highway Safety and Parking

If your extension converts a garage into living space or removes off-street parking, the council’s highways department may object. Similarly, if your project creates a new driveway with poor visibility, it will be refused on safety grounds.

Mitigate the Risk with Data

The best way to avoid a refusal is to know what your local council cares about before you apply. Planzoola analyses thousands of local planning decisions to show you the specific refusal trends in your borough. If your council has a 60% refusal rate for side extensions due to "loss of light," Planzoola will alert you immediately.