4, Cavendish Square W1

No. 4 Cavendish Square is a substantial terrace house dating from around 1740. The facade has been largely refaced in variegated stock brick with red brick dressings in the early 20th century. The building stands four storeys high, with a basement and a slated mansard roof featuring dormers. It has four windows and includes brick plat bands and a brick modillion parapet cornice with a blocking course.

The entrance features a Portland stone Doric portico with recessed bays and a round arched doorway. There are Portland stone balustered balconettes on the first floor, and the revealed sash windows have segmental gauged arches and shaped brick aprons at the sills. Cast iron area railings with tasselled spear heads return up the steps.

Although the interior was refurbished around the same time as the facade, much of the original detail remains. The large front compartment staircase hall leads up to the piano nobile and features open string stairs with carved bracket tread ends, corkscrew balusters, and a handrail that ramps to Corinthian column newels. The dado on the wall corresponds with the balusters that return to the gallery landing, and there is fielded panelling on the walls. The plasterwork ceiling includes Rococo details, and there are pedimented doorcases among other features.

The building is associated with Lord Nelson.