Overlooked requirements: Some people think as long as you can fit a bed in a loft then conversion can be classified as a bedroom.
The loft needs to be a ‘useable space’ and different Boroughs and District Councils will interpret useable space in different ways.
Required is a proper staircase leading to and from it and enough head height to access the room and walk around the bed comfortably. Not forgetting 50mm of insulation is required which can impact the headroom.
Building regulation require a safe means of escape which differs the higher you go.
You must have planning consent and Building Regulations approval.