No 240 (Former Chertsey Lock House)

This is a late 1812-13 lock-house, altered in the 1830s and after 1897. It was designed by Stephen Leach, Clerk of Works to the Corporation of the City of London, and is constructed of painted brick and stucco, with a slate roof. The building consists of a central gabled wing with a projecting chimney breast featuring arcading; a flight of steps leads to a half-glazed door with a modern porch, and a sash window with glazing bars and horns is to the right. Flanking wings, added in the late 19th century, have parapets. The north wing has a wide round-arched blocked opening in the north end wall, a sash window with horns and glazing bars, and a post-1897 canted bay window with sash lights. The south wing has a similar front elevation, with a blocked window opening to the right. The south elevation of the south wing includes a post-1897 three-light sash window with horns, replacing ledged doors and an arch matching that in the north wing's north elevation.

The cellar under the central wing features a stone flagged floor and exposed wood ceiling beams and joists. The cellar of the north wing has a brick floor and two blocked door openings in the rear wall. The main floor includes mid to late 19th-century fireplace surrounds, panelled doors, and steps leading up from the flanking wings to the original central wing. The central wing retains a king-post roof truss with a ridge piece.

This lock-house is one of six apparently designed by Stephen Leach and built in the early 19th century to accompany new locks on the River Thames, commissioned by the Corporation of the City of London between Penton Hook and Teddington. The other five were built to two storeys and cellar, to a similar pattern. Chertsey lock-house appears to have been a one-story and cellar building, likely to preserve the view from Lord Lucan’s Laleham mansion. In 1835, alterations were proposed to raise the roof, back wall, chimneys, partitions, floors, and window frames, similar to changes made at other lock-houses. In 1838, the lock-keeper requested connecting a portion of an adjoining warehouse to the lock-house to create two small rooms. The original appearance of the lock-house before 1897 is depicted in John Leyland’s 'A Picturesque Journeying from Richmond to Oxford'. The Chertsey lock-house is one of three remaining lock-houses built to the original design.