Former Chapel at North West Corner of Garden to Number 7 Former Chapel in Outer Ward of the Castle, with Wall Attached

The building is a 19th-century byre incorporating fragments of the Chapel of St Margaret, located in the outer ward of Barnard Castle. Parts of the structure date to the 12th and 13th centuries. A wall is attached to the byre, and a further wall runs south behind the gardens of houses along The Bank.

The byre has a square plan, situated against the corner of a garden belonging to number 7, The Bank, and lies west of number 6, Market Place. It is constructed of rubble with ashlar dressings, and has a pantile roof with a stone ridge and stone slates at the eaves. The attached wall is of coursed rubble with ashlar dressings.

The north elevation of the byre features a boarded Dutch door at the left and a window with hit-and-miss vents below three panes to the right. The return elevation on the right has a stone lintel over a blocked central door. The south elevation, facing the garden, shows a blocked door with left block jambs, disturbed masonry, and a blocked opening with a flat stone lintel and well-cut block jambs.

The interior, largely obscured by limewash, contains a fragment of a round pier approximately 0.8 metres high, of 13th-century character, with a moulded plinth. Above this fragment are two blocked rectangular lights. The attached wall, approximately 3 metres high, has a boarded door with block jambs and two lancet windows with stone slate shelves; the left lancet head comprises a single stone, the right head of two stones resting on block jambs and a mullion. The wall extends north-south to join the Castle Wall and has irregular coping.