20, Montagu Street W1

No. 20 Montagu Street is a terraced town house built around 1790 to 1800, with some minor alterations from the early 19th century. It is part of the Portman Estate development that extends from Great Cumberland Place. The building is constructed of stock brick, featuring a channelled stucco ground floor and a concealed slate roof. It has five storeys and a basement, with three windows across the front.

To the left, there is a square-headed doorway, which is sheltered by a stucco porch supported by Doric columns. The entrance includes a panelled door and a fanlight above. The upper floors have recessed sash windows that are set beneath flat gauged red brick arches. A plat band marks the top of the ground floor stuccowork. The building is topped with a stucco cornice and a blocking course. A continuous cast iron balcony with a geometric pattern is present on the first floor, and there are cast iron area railings with tasselled spearhead finials.