Spelthorne St Mary

Spelthorne St Mary is a former large mansion that later became a convent and is now part of the American School in Switzerland (TASIS). It was built in the early 19th century and features yellow brick walls with hipped slate roofs and numerous chimneys. The building has three storeys.

On the garden elevation (south), the ground floor has three 12-pane sash windows at the center. The first floor has three similar windows, while the second floor features three 6-pane sashes. There is a plain pediment and a parapet with stone coping only at roof level. On either side, there are two-storey splay-sided bays with sash windows in the splays and French windows at ground level, both with parapets and coping.

To the east, there are large extensions of two and three storeys that match the style and materials of the original building. The west elevation is three storeys high with a parapet and includes a similar two-storey bay window on the left. The three bays to the right consist of one window and two recesses on the ground floor, two windows and one recess on the first floor, and one window and one recess on the second floor. At the end of the bay, there is a porch supported by two Tuscan columns, featuring a flat entablature with triglyphs and a single glazed door, along with a corridor link to the chapel.