Report on a historic building survey undertaken to inform the proposed conversion of the Old Coach House, Horncastle, into a residential property. The coach house is to the rear of 15 Queen Street, with which it was formerly associated. Dating to the mid-late 19th century, it is a two storey red brick building under a pitched hipped slate roof. The ground floor is divided into two rooms, separated by a central stair. The northern room appears to have been built as a stable, with an integral drain built into the brick floor and the remains of a probable hay rack on the east wall. It has room for up to two loose boxes, though no internal division remains. The southern room was likely originally a workroom with a small tack room and a small coach house. Both rooms are lit by demi-lune windows and are accessed by large openings in the west elevation, though the segmental arch of the northern opening has been replaced by a flat concrete lintel. Above is a former hay loft, with a loading hatch in the north elevation.