The defensible lockmaster's house at Chaffey's lockstation occupies the north side of Chaffey's Lock Road south of Chaffey's lock.
The Chaffey's defensible lockmaster's house was built of limestone in 1844 as a lower cost alternative to a blockhouse. It was originally a single storey building with a tin roof to protect it from fire and with gun slits to provide defence in case of attack. The house was continuously occupied by five lockmasters from 1844 to 1967. In 1894 the house was renovated with the addition of a second storey, a kitchen, and a pyramidal-shaped roof. On August 16, 1990 The Government of Canada recognized the Chaffey's lockmaster's house as a federal heritage building, according to Treasury Board Heritage Buildings Policy.