17, 19 Dundas Street, Bonnyrigg

17 and 19 Dundas Street is a mid 19th century classical house that has undergone later alterations and has an addition at the rear. The building is two stories tall with a four-bay rectangular plan, constructed from stugged ashlar sandstone, with sandstone rubble at the rear and a harled elevation on the southeast side. It features droved, raised margins around the windows and a droved, chamfered, architraved doorway. There is a base course and an eaves course, along with three-quarter height buttresses on the southeast side.

On the northeast (principal) elevation, the central bay contains an architraved doorway with a timber panelled door and a two-light fanlight above, with a window located above it on the first floor. Each of the flanking bays has a window on both floors. To the outer right, there is a replacement door with a blinded fanlight at ground level and a window above it on the first floor. A walled path leads to a redundant door located to the right of the principal elevation.

The southwest (rear) elevation is also two stories with four bays. It features a single-storey square plan addition in the center, which has a window on the southeast side and a door on the left return, with a non-aligned window above on the first floor. There is a window in the bay to the right on the first floor and a window at each floor in the bay to the left. A lintelled opening leads to a pend at ground level in the outer left bay, with a window above it on the first floor that has 12- and 4-pane timber sash and case windows. The roof is piended with slate, and there are ashlar coped skew and wallhead stacks on the southeast and right sides, respectively. The building also has cast-iron rainwater goods.

The boundary wall is made of ashlar sandstone with a curved cope, while the walls flanking the path to the pend are constructed from sandstone rubble with a curved ashlar cope.