Do I need Planning Permission to Convert the other side of the loft

[Gilmoregirly]

We already have a bedroom in one side of the loft and a staircase. Do we need planning permission to convert the other side of the loft to add another bedroom and an en-suite to the existing loft room please.

Hopeful bump

No it would be permitted development I think. Subject to building regs though of course.

Unless you're adding a dormer etc as part of the conversion - that would need PP.

Thank you @pinkoryelloworgreen . We are not adding a dormer but want to add a roof light.

Likely to be permitted development unless you’re in a flat, or it’s a listed building, or you’re in a conservation area/national park etc.

Are you in Conservation area, AONB or have any restrictions? Will the roof light be facing the street? What other additions have been made to the footprint of the property?

no we are not in Conservation area, AONB nor have any restrictions. Our home is a detached house. The roof light will face our garden to which the other roof light in the loft room faces.

Sounds as though it will be permitted development.
You will need approval under the Building Regulations though.