The damage caused by the flood took several years to repair. Millbank, the most seriously affected area, was largely rebuilt from scratch; many of the run-down dwellings and warehouses that had characterised the area were so badly damaged that they had to be demolished, while the rest were torn down as part of the area's post-flood regeneration. They were replaced with modern office blocks and apartment buildings. Imperial Chemical House (designed by Sir Frank Baines, the Principal Architect of the Government's Office of Works), was one of the new buildings constructed in the area in 1927–29. The current headquarters of MI5, Thames House, was built to a very similar (though not identical) design in 1929–1930 on the other side of Horseferry Road, with the two buildings forming a landmark pair of office blocks facing the river.