A file of correspondence concerning building projects at Bletchley Park (occasionally referred to as BP) to accommodate expanding manpower requirements in 1942. Subjects covered in the file include delays in and the abandonment of a plan to expand "Block B" at Bletchley Park, and related problems in the relationship between the Ministry of Works and the administration at Bletchley; plans to build a new set of buildings, "Block E", at Bletchley Park; Treasury concerns about the necessity of parts of the projects; and the need for more accommodation, training and entertainment facilities at Bletchley.