It can be a confusing topic, and it really helps with local campaigns to improve your area or protect the countryside if you can feel confident in understanding the planning rules.
The CPRE (The Campaign to Protect Rural England) have a few practical guides to help you make sense of it all and influence the future of your local area. We have added the links to these below so that if they are updated you are going to get to the most recent versions.
How to respond to planning applications
How to shape where you live – a guide to neighbourhood planning