There is a hay barn suitable for a two storey renovation. it is covered in sheet metal on the 18m west elevation and the 8m north elevation. the other two sides are open. the sides with the sheeting a 5ft block walls and a floor slab troughout, depth unkown. the roof is bowed and 4.7m at the eaves. I saw the case of Hibbet which had one wall blocked off and 3 open walls on a steel frame and metal sheet roof. I am wondering whether the conversion issue or rebuilding may be the issue here. it will need new walls, repalcemetn roof sheets, windows, doors, insulation walls themselves. I am not sure whether a full planning app is needed or if permitted development would work here