Pirn Inn, Banker's Brae, Balfron

The Pirn Inn, located on Banker's Brae in Balfron, is a late 18th and early 19th century building that has undergone several expansions and alterations. The original block is a 3-bay, 2-storey structure, which was extended to the west during the earlier to mid-19th century, likely when it functioned as a bank. A further single-storey addition extends to the north. A linking bay connects both main blocks. The building is now a public house.

Architecturally, the original block and the western extension each have a rectangular plan and are regularly fenestrated on their south (principal) elevation, with later gabled porches added. The western block is slightly taller than the original. The exterior is built of roughly coursed stone, except for the south elevation of the western block, which is rendered and lined to resemble ashlar. Both sections have a base course. The original block features an eaves band, while the western block has a frieze and eaves cornice, along with vertical margins at the arrises. The windows on the western block's southern elevation have moulded architraves, with the ground-floor architraves extending down to form aprons. The ground-floor windows of the original block have been slightly enlarged and retain architraved surrounds.

On the south elevation, the original block's central entrance is adorned with a gabled porch displaying a carved coat of arms, a panelled timber door, and windows on either return; the right return having a round-arched window. An upper window is directly above the entrance, and there is one window per bay on the ground and first floors. The linking bay has a cornice above the ground floor and windows on both floors, with a gabled, round-arched dormer breaking the eaves. The western block has a gabled porch over its entrance with a two-leaf timber door and small windows on either return. The ground and first floors of the western block are each pierced by two windows, though the window to the left of the ground floor may have originally been an entrance. The attic of the western block has a pair of modern, piended dormers.

The east elevation shows a small attic window to the gable end of the original block, with a single-storey addition adjoined to the right, including a gabled section, likely a former stable block. The west elevation features a central timber door and an inserted window on the gable end of the western block, as well as a central window to both the first floor and the attic. The north elevation of the building, including both blocks, is largely hidden by later additions, but a nepis gable is visible at the center of the western block.

The majority of the windows on the south elevation are timber sash and case windows with 12 or 2 panes. A fixed, heraldic leaded-glass window is found on the upper storey of the linking bay. The roof is covered with grey slate, and the original block and west extension are topped with coped gablehead stacks. A nepis stack is located on the north side of the western block.

The interior, particularly the ground floor, has been significantly altered for its use as a public house.