23, Nassau Street W1

No. 23 Nassau Street is a terrace house built around 1770-1780. It features a brown brick exterior with a rusticated stucco ground floor and a slate roof. The building stands four storeys tall and is three windows wide. The entrance is located on the left and is highlighted by an elegant wooden doorcase with engaged Doric columns, triglyph dosserets, and a mutule pediment, which frames a six-panel door with a fanlight above. The ground floor has rustication that extends to the flat window arches. The upper floors contain recessed sash windows without glazing bars, set under flat gauged arches. The parapet has coping.

Inside, the ground and first-floor front rooms are simply panelled and feature fluted friezes and sharply profiled cornices. There is a geometrical staircase with enriched S-pattern wrought iron balusters. Notably, No. 23 was the residence of the geographer James Rennell in 1792, as indicated by a plaque from the Greater London Council. The quality of the doorcase suggests a connection to the now-demolished contemporary houses designed by Robert Adam in Berners Street.