Between 1834 and 1860 the British government mobilised the latest scientific knowledge in the construction of the new Palace of Westminster, home to the nation's Houses of Parliament. Built in a Gothic style, this legislative building embodied the latest experimental techniques and expertise from geology, mathematics, engineering, chemistry, and optics. By exploring the narrative of this architectural project, it becomes clear just how central scientific values were to Victorian politics. At the same time, this article shows how the experience of constructing Britain's nineteenth-century parliament building has implications and lessons for parliamentary architecture today.