Water Pavilion At Carshalton House

The Water Pavilion at Carshalton House is an early 18th-century structure, completed before 1721, and is likely designed by Henry Joynes. This building is one storey high, featuring a square tower that rises three storeys. The ground floor is constructed of brown brick with red rubber brick dressings. The west front has a 1-3-1 arrangement of old round-headed sash windows, each with stone keystones, and the central three windows project fully. The corners of the building have angle piers with stone bases and fluted capitals. There is a plain frieze, a band-cornice, a tall parapet, and a moulded stone capping.

At the rear of the centre front, the tower features a large open round arch with a keystone and cill on brackets on each face. Attached piers with stone cornice tops rise to the springing level of these arches, supporting flaming vases. The top of the tower has a segmental cut-out frieze of brick, along with brick and stone bands, and diminutive Flemish gable style crenellations capped with ornamental pyramidal corner finials topped with balls. The tower's fronts are uniform, while the ground floor fronts are also similar. The north front is short, but the south front, which serves as an orangery, has a long range of windows.

Inside, the entrance hall is located at the centre of the east front and features a Vanbrughian ceiling supported by pendentives and a dome. To the north is the bathroom, which contains an original marble-lined plunge bath and walls completely lined with blue and mauve Delft tiles. The pump chamber includes brick piers and arches, a water channel, and a wheel; water flows beneath the building (formerly into the lake) and is pumped into a tank at the top of the tower to supply the house and bathroom. The original wheel was removed in 1960.

The Water Pavilion and the boundary wall to Carshalton House form a group with nearby properties, including Nos 3 to 11 (odd) and No 15 West Street, as well as Nos 2 to 12 and 18 to 24 (even) West Street, and The Old Rectory on Festival Walk.