Imperial Chemical House has five main storeys, with a four-storey attic and pitched leaded roof. It was constructed on a steel frame, with the ground floor façades faced in grey granite. The higher floors are faced in Portland stone, rusticated on the second to fifth stories. There are 27 bays including three doors along the Millbank façade, seven bays including one door in the corner splay at the junction of Millbank and Horseferry Road, and five bays along Horseferry Road. To the rear, part of the building faces onto Smith Square.