Re-appraising, rebuilding The House of Commons environment.

The House of Commons, destroyed during air raids in 1941, was rebuilt between 1944 and 1950, incorporating a sophisticated air conditioning system. This was portrayed as a radical departure from the nineteenth-century technology of its Victorian predecessor, but new research has revealed that its design was building on the findings of earlier investigations into improving the historic system, addressing questions thermal comfort and user experience. This article explores the process by which occupants, scientists and engineers collaborated to empirically evaluate and improve the historic system, focusing on the period from 1913 until 1937, and how this had informed the design of the new system for the post-war debating chamber, which was developed between 1943 and 1950, also became subject of post-occupancy evaluation two years after its completion. This offers critical insights into practices in environmental design in the first half of the twentieth century.