12, Upper Grosvenor Street W1

No. 12 Upper Grosvenor Street is an end-of-terrace townhouse built around 1728 by Benjamin Turnbull for his own use, with early 19th-century alterations and likely heightening. The building is faced with stucco and has a slate roof, rising four storeys above a basement and featuring four windows across its façade. The ground floor is channelled, with an entrance on the left that includes a six-panel door flanked by sidelights and topped with a patterned fanlight under a square head. The recessed sash windows above have channelling struck to flat arches, while the first and second floors feature segmental arched windows with architraves, the first-floor windows adorned with pediments. Shallow corner pilasters frame the upper floors, leading to a crowning cornice and blocking course, with plat bands at the first and third floors. A geometric pattern cast iron balcony from the early 19th century is present on the first floor. The return to Park Street is painted brick with irregularly placed windows. The property has cast iron area railings with urn finials. Inside, the layout likely retains its original plan, showcasing primarily early 19th-century features alongside early 18th-century doors and doorcases in the hall, as well as a geometric staircase with iron balusters.