In the 1960s Debenhams department stores planned a new, flagship store on London's Oxford Street. Westminster Council's planning regulations at that time required such schemes to provide parking facilities, hence, a car park was commissioned behind the new shop and opposite the head offices, occupying a plot facing onto Welbeck Street, Henrietta Place and Marylebone Lane. The brief was for a car park for 400 cars, storage for the department store space. Michael Blampied and Partners won the commission; the firm had undertaken many large scale commercial and residential schemes during the 1960s, in Britain and abroad. The new department store was built concurrently, to the designs of Adrian V Montagu and Partners.
The site, a somewhat awkward wedge shape, inclines towards Marylebone Lane, and a split-level design with ramp access was deemed the most suitable, though other arrangements were investigated. Split-level parking was, by this period, already an established form. Structurally, the building has a central spinal stack containing a lift and staircase, and external load-bearing walls of precast concrete V-shaped interlocking modular units. These support reinforced concrete beam and plank floors and negate the need for internal columns, providing uninterrupted parking decks facilitating easy maneuvering and clear lines of sight.
Unlike the department store, Blampied's car park attracted coverage by the architectural press. In a comparison of three car parking schemes, the Architects' Journal (1971) commended the successful approach. 'Building' (1971) reported that it 'expresses both the function and the construction in a dynamic and visually exciting structure' and that the development should do much for the tarnished image of car parking buildings generally, which, during the period were built in vast numbers but exhibited, generally, a dearth of architectural quality. In opposition to this, Blampied's design put aesthetic quality and structural ingenuity on a par with functionality creating a striking yet eminently practical building.
From the outset the facility was under used. Westminster's statutory undertaking for car parking as a condition of new development was bolstered by the 1963 Buchanan report, 'Traffic in Towns', published by the Ministry of Transport, which advocated urban multi-storey car parking. However, as stated in the Architects' Journal, motorists were not yet educated in using car parking buildings, preferring on street parking. It is suggested that only further on-street parking restrictions would increase use. The lack of a 'reservoir' in which cars could queue for entry would have resulted in traffic jams on Marylebone Lane, had customers been more numerous. The car park has remained in use since it opened in 1970, though custom remains low owing to Central London's traffic restrictions and the good provision of public transport.
The lettable units have undergone alteration to suit changing occupants. In the basement was a large refrigerated stock room for storage of furs; this was in use for a limited period as tastes in fashion changed. A subterranean linking tunnel to Debenhams head offices at No. 1 Welbeck Street remains extant.