Came across this building in the grounds of an old manor house. I don't know what its original use was but it is currently being used as the estate management office.
@julzmaioro Thank you for your comments Julia, gatehouses are always on the entrance to a manor or stately home from the main road this was tucked around at the back out of sight:)
@onewing Thank you Babs I found its shape interesting original building was an Hetegon (7 sided) with an additional oblong section added at the back much later I believe should have go into the office and asked its history:)