A large part of Penn has been absorbed progressively into Wolverhampton, which became a County Borough in 1930 and a Metropolitan borough in 1974, thus detaching much of Penn from the administrative county of Staffordshire. This gradual expansion of the boundaries of Wolverhampton was accompanied by a rapid development of suburban housing, particularly from the Edwardian period, with many residents depending on the Sunbeam works for employment. Despite the depression of the 1930s, a further surge in housebuilding occurred, with much post-war infill. As a result, the area to the north and west of St. Bartholomew's church is almost entirely occupied by Wolverhampton's suburban housing.