Barry planned an enfilade, or what Christopher Jones, the former BBC political editor, has called "one long spine of Lords' and Commons' Chambers" which enabled the Speaker of the House of Commons to look through the line of the building to see the Queen's throne in the House of Lords. Laid out around 11 courtyards, the building included several residences with accommodation for about 200 people, and comprised a total of 1,180 rooms, 126 staircases and of corridors. Between 1836 and 1837 Pugin made more detailed drawings on which estimates were made for the palace's completion; reports of the cost estimates vary from £707,000 to £725,000, with six years until completion of the project.