South West Steading Range, Thornybank House, Dalkeith

The North West Steading Range at Thornybank House in Dalkeith is a group of single-storey farm cottages built in the mid-19th century. The cottages are arranged in two L-plan ranges that are connected by a gateway, creating a Z-plan layout. They are constructed from squared and snecked rubble with ashlar dressings, featuring eaves and base courses, as well as chamfered reveals and cills on a variety of doors and fanlights.

The gateway consists of two gatepiers and screen walls located at the center of the east-west range. The gatepiers are made of rusticated ashlar, topped with pyramidal caps, and have chamfered angles, a band course, and a cornice. Modern gates are installed, and the gatepiers are connected to the adjacent ranges by flat-coped ashlar screen walls, each containing a doorway.

The L-plan range to the west has a south elevation with nine asymmetrical bays arranged in a 2-1-4-2 pattern. There is a blocked segmental carriage-arch in the outer left bay, and a clock is set in a gabled stone surround above the eaves. The central bay features door number 4, while the remaining bays are fenestrated.

The east elevation of the west range has ten bays arranged in a 4-3-3 pattern. Door number 1 is located in the third bay to the left of center, door number 2 is in the bay to the right of center, and door number 3 is in the penultimate bay to the right. The other bays contain bipartite windows, with a flat-roofed canted bipartite window to the right of the left return and another bipartite window to the left.

The west elevation of the west range has a later flat-roofed harled addition attached.

The L-plan range to the east has a south elevation with four bays arranged in a 1-3 pattern. Door number 5 is in the bay to the right of center, while the remaining bays are fenestrated.

The east elevation of the east range features fifteen bays arranged in a 1-3-1-1-3-3-3 pattern. Door number 6 is in the fifth bay to the left of center, door number 7 is in the center bay, door number 8 is in the third bay to the right of center, and door number 9 is in the penultimate bay from the right. The other bays contain bipartite windows, and there is a blocked doorway between the second and third bays from the center.

The west elevation of the east range also has a later flat-roofed harled addition. The cottages display a variety of glazing patterns in the sash and case windows, including 4-pane, 8-pane, and 12-pane designs. The clock on the west range is skewed to the left. The roofs are covered with grey slates and have piended designs, with coped ashlar and rendered stacks, primarily located at the ridge and gablehead to the southwest.

To the north of the cottages is the steading, which backs onto the cottages and features a variety of windows, doors, and machinery doors on its north and east elevations.