This was filmed at Crom Castle in Northern Ireland.
Beach's name was inspired by Beach Road, a road in the town of Emsworth, England, that leads to the seashore. The road is located near a cottage called Threepwood, which book series author P.G. Wodehouse rented in the early 1900s.
The full names of the characters Clarence Threepwood (9th Earl of Emsworth) and Sebastian Beach are never spoken in the series, although the name Threepwood is attached to Clarence's male relatives who appear in the show.
Timothy Spall (Lord Emsworth) and Mark Williams (Beach in season one) both played alumni of House Gryffindor in the Harry Potter movies.