Thornybank House, Dalkeith

Thornybank House is a mid 19th century, two-storey farmhouse with an asymmetrical design and a first floor that breaks the eaves. The exterior is finished in stugged ashlar with a base course, raised margins, and angle margins, featuring deep overhanging eaves.

The principal elevation has a corniced basket ashlar porch at the center, which is set in a re-entrant angle formed by a broad advanced gabled bay to the right. The porch has a leaded roof and a panelled door. In the advanced bay to the right, there is a corniced canted window with a half-piend leaded roof at the ground floor and a window at the first floor. To the left, there is a broader window at the ground floor and a dormer-headed window at the first floor.

The south elevation is three bays wide, with an advanced gabled bay to the right that features a broader window at the ground floor and a window at the first floor. At the center, there is a gabled two-leaf door that has been enlarged from a window, along with a dormer-headed window at the first floor. There is also a window at the ground in the left bay.

The north elevation is also three bays wide. It has a window at the ground and a piended dormer-headed window at the first floor in the right bay. The center features a shouldered off-set chimney-breast, while the left bay is blank. There is a later rendered gabled projection forming a porch, which is adjoined to the west gable by a single-storey block to the left and a two-storey lean-to to the right. The porch has a two-leaf door to the right and a window to the left, with two windows on the left return.

The west elevation has a window at the first floor in the gabled bay to the right. There is a single-storey gabled wing running north, which is adjoined to the left and features a window at the center to the west, a door at the center, a window to the left, and a garage door to the right on the east side.

The windows are timber mullioned with a lying-pane glazing pattern, some being three-light and others featuring unusual vertical sliding sashes. The house has corniced stacks located at the wallhead to the north, gablehead to the west and south, and a ridge to the south pitch, all covered with grey slates, with some original cans still present.