As long as your property is not in a conservation area or is a flat, you have permitted development rights (PD). This means you can usually develop your loft space without needing to gain planning permission. Your loft conversion development will need to keep within the permitted development constraints i.e. terraced properties are allowed to develop an additional 40 cubic metres of extra space. Semi-detached and detached properties = 50 cubic metres. If your loft conversion design meets these requirements then you can apply for a certificate of lawful development from your local council. If you do not meet permitted development rights, then you will need to apply for planning permission for your loft conversion project.
>> What is permitted development?
