How big an extension can I build without needing planning consent?
• Answer: The rules are too complex to explain in a simple form here, and in all cases we would recommend that professional advice is sought. As an indication, providing that you are not in a conservation area or a listed building, and providing permitted development rights have not already been removed, the following gives a guide: (i) if you are in a flatted property, you need permission for virtually all extensions and developments.
