Mrs C

We live in an old farm house which is grade 2 listed, and surrounded by several very old barns which are considered in the curtilage. There is a modern barn further from the house (approximately 20 metres away) which was built after 1948, but was used as part of the farm until the farm was split and sold about 15 years ago. Does the fact it is post 1948 mean we can put solar panels on the barn roof under permitted development rules? Thank you