The original intention was to build a circular tower similar to the London one but without the public floors above the aerial galleries. At one time the Post Office wanted to increase the height from , which had been agreed by the Ministry of Aviation, to . This was refused in order to avoid non-standard procedures for aircraft approaching Birmingham Airport from the north-west. Cost over-runs on the London tower led to a review of the Birmingham design, and then it was decided to use a circular design of the 'Chilterns' type as used at Stokenchurch, Charwelton, Pye Green, Sutton Common, Heaton Park and Tinshill radio stations, but with the internal diameter increased from to to provide sufficient space on the equipment floors. The square design, as built, was proposed for aesthetic reasons by the Chief Architect of the Ministry of Public Building and Works.