Old Tay Works Mill, 25 Brown Street, Dundee

This is an early 19th-century flax mill, situated at 25 Brown Street, Dundee. The core of the mill complex dates to circa 1833-36 and is constructed of rubble, with an iron frame.

The original mill section (a) was built between 1834 and 1836. This is a three-story and attic structure with ten bays, featuring a three-bay gable to Brown Street. The gable includes a hoist door at the second floor and two windows in the attic. A projecting one-by-two bay stair and hoist door section is present, topped with a pedimented gable, an oculus, and the base of a small bellcote on its eastern side. Windows on the north elevation have been blocked up, while the others are multi-paned sash and case windows, some retaining their original hoist doors. Attached to the east gable is a tall engine house with two round-headed windows facing north and south; one window has a larger door inserted to accommodate a replacement engine.

A western wing (b), constructed circa 1836, is also three stories tall with a smaller attic. It has seven bays facing Brown Street and a blank southern gable decorated with skewputts and a flat-topped finial. The windows facing Brown Street are four-paned casements, while the rear windows are multi-paned sash and case.

Between 1849 and 1851, a two-story batching house (c) was added, forming a U-plan layout with the main mill. Its walls are partially obscured by later concrete external stairs. The building has a piended roof, and the court is covered by kingpost trusses. Ground floors of two- and three-story blocks are supported by stout, flanged iron colonnades. A one-story batching shed with a piended roof was added to the south circa 1889-91. All roofs are slate.

The interior of the mill is characterized by an iron frame and brick arched construction, with stone flagged floors. The oldest mill section has two rows of iron columns with Bell capitals, eyelets, and no visible tie-rods. The western wing has a single row of columns. A fine spiral stair is also present, as are timber collar-beam roofs. The engine house has a massive masonry base with a wooden stair and platforms and features a large belt-driven pulley.

A West Mill, dating to circa 1851, is located between the dyeworks and the Lochee Road block. This two-story rubble, iron-framed block was used for batching, preparing, and winding, and features five wide arched ground floor doors. Fourteen large cast-iron brackets supported a lean-to roof (now without glazing) that connected to the main mill. The interior is iron framed. This section is topped with a piended slate roof. The adjacent engine house (1851) is built of rubble with two round-headed windows, a cornice, a parapet, and a piended slate roof. Its interior is plastered and painted, with decorated corbels and a timber roof. The engine house originally powered a power-loom factory (now demolished) and later the northern section of the Lochee Road block. The north elevation is blank and has a cornice running along the top, directly adjoining a 1851 square-section chimney constructed of rubble to the height of the engine house, with brickwork and firebrick at the top.