Mill Number Three With Turbine House, New Lanark

Mill Number Three with Turbine House in New Lanark was built between 1826 and 1833. It is a six-storey, fifteen-bay rectangular building designed in an astylar classical style with a piend roof. There is a five-storey, three-bay link to the former Mill No. 4, which has a separate piended roof. The main block is symmetrical, featuring an advanced central section with a gable-pedimented design that includes three bays, an oval oculus, and a chimney at the apex, along with advanced single outer bays. The link to the outer left has a central doorway.

The building is constructed from sandstone rubble, with droved and stugged ashlar dressings. It has a band course at the pediment, an eaves course, and a blocking course on the advanced outer bays. The corners are accented with long and short quoins. The windows are regularly spaced and feature tabbed ashlar margins, with small dormers on both the front and rear of the main block. There is a large opening on the left at the first-floor level, which has a covered late 20th-century ramp leading from the Institute to the first bay of the third floor.

The windows are timber sash and case, with 16-pane and 12-pane glazing. The building has a coped stack and is roofed with grey slates.

Inside, some 19th-century details remain. The construction is fireproof, featuring brick arches between cast-iron beams supported by cast-iron columns. The basement floor is laid with black and red floor tiles. A unique cast- and wrought-iron roof frame is present at the eastern end of the link section, and the attic is floored with cast-iron plates. Additionally, there is a 1920s turbine located in the basement.