The original plan was for eight platforms, but half were designated as a "possible future extension" and the cost of building the GCML was greater than expected. The line leading to the station cut through of middle-class housing, including the Eyre Estate in St John's Wood and the area around Lord's, drawing protests and requiring a relocation of the track and station facilities. There was never enough money for the extra platforms, and only four were built, three inside the train shed and one to its west (platform 4). As a result, the concourse is unusually long and had three walls for most of the 20th century. The northern wall was missing, as the GCR anticipated that the other four platforms, under an extended train shed, would be built later on. An office block was later built on the vacant site. The cost of the London Extension meant that the adjoining Great Central Hotel, designed by Sir Robert William Ellis, was built by a different company. The hotel operated for a relatively short time and was converted to offices in 1945, becoming the headquarters of British Rail from 1948 to 1986. The offices were restored as a hotel in 1993.