Whether you need planning permission for annexes and leisure buildings depends on several factors, such as their size, location, and intended use. In general:
Annexes: If the annex is attached to your existing home, it may be considered an extension and could fall under permitted development rights. However, if it is a separate building, it may require planning permission, especially if it exceeds certain size limits or is used for residential purposes.
Leisure Buildings: Small, detached structures used for leisure purposes (such as a garden room, gym, or pool house) may not require planning permission if they fall within the size limits and are not intended for permanent residential use.
To ensure you are compliant with local regulations, it's always advisable to contact your local planning authority (LPA) through your local council to confirm if your project requires planning permission.