107 and 109, Harley Street W1

These are a pair of terraced town houses, built around 1777 as part of the Harley Street Portland Estate development. The design was likely a partnership between John White and the plasterer Thomas Collins, both associates of Sir William Chambers. The houses are constructed with stock brick, with boldly channelled stucco on the ground floors, and have slate roofs. They feature a bowed rear elevation.

The houses are four storeys high, with basements and dormered mansards, and each has a three-window front. They have broad, semicircular arched doorways on the left-hand side. Number 109 retains its original vermiculated Coade stone surround to the doorway, featuring a head keystone. Number 107 was likely altered around 1900, introducing a curved cornice and panelled jambs flanking the door, which sits beneath a fanlight. Number 109 retains its original panelled door, with framed side lights and a patterned fanlight designed as a Venetian window composition. The upper floors have recessed sash windows within stucco architraves, with cornices above on the first floor. The houses have parapets with stone copings. 19th-century cast iron bombé balconies are present on the first floor, along with cast iron area railings topped with urn finials.

The interiors are of a high quality, characteristic of the prestigious Harley Street houses of the 1770s. They are more elaborate than typical examples, featuring arched hallway openings leading to top-lit, stone geometrical staircases with scrollwork wrought iron balustrades. The ceilings and friezes display delicate plasterwork including flutes, palmettes, and wreath-and-garland motifs. Stucco mythological relief medallions, reminiscent of the work of Sir William Chambers, are framed by garlands and inlaid marble chimneypieces supported by Ionic columns and pilasters. Other original features include mahogany doors and panelled shutters.