Tramway Power Station, 179 Constitution Street, Aberdeen

The Tramway Power Station, located at 179 Constitution Street, Aberdeen, was originally built in 1885 by Jenkins and Marr, and subsequently substantially remodelled in 1920 by the City Architects Department. It is a long, rectangular building with an asymmetrical classical two-storey, seven-bay principal elevation, and a single-storey section to the rear.

The building is constructed of tooled coursed granite ashlar with finely finished margins on the principal elevation; coursed granite rubble in Aberdeen bond is used elsewhere. A bull-faced base course, ground floor cill course, dividing band, 1st floor cill course, band course above the 1st floor, and eaves cornice are also present.

The south-east (principal) elevation features an advanced three-bay pedimented central block. The ground floor of the centre bay has a pilastered and architraved doorpiece with stone steps leading to a modern glazed door; the left and right bays have corniced single windows. The first floor features a bipartite corniced window in the centre bay, flanked to the left and right by corniced single windows. A blind oculus with a moulded surround sits at the centre of the pediment. To the left of the central block, a stepped-down, recessed two-bay linking section is present, with a large glazed opening and infill screen, topped by a modern glazed canopy, to the left bay, and single windows to both ground and 1st floors in the right bay. An advanced single-bay pavilion on the far left has a shallow segmentally-arched opening with modern glazing and a single window to the 1st floor. To the right of the central block, a recessed single bay block is flanked by lower shaped skews. A double-height basket-arched opening with raised long and short quoins and voussoirs, infilled by a modern glazed screen and door, is centrally positioned, with a modern glazed canopy extending between the ground and 1st floors. A single-storey, flat-roofed section is located to the far right, constructed of Aberdeen-bond granite ashlar, with a door at the centre.

The north-west (rear) elevation comprises two gables, with an advanced gable to the left of modern construction and a blank gable to the right. The north-east (side) elevation is predominantly blank, with an advanced, five-bay, single-storey building to the left. The south-west (side) elevation is predominantly blank, with an advanced section to the right and a modern brick lean-to extension to the ground floor on the left.

Most of the glazing is modern, set within metal frames. The roofs are predominantly grey slate pitched, with some corrugated roofing to the rear. Stone skews are also present. Corniced masonry wallhead stacks are located to the left and right of the central block, and a corniced gable-head apex stack is located at the rear of the central block.

The interior of the centre block features a dog-leg stair with ornate cast-iron balusters on the upper flight and landing. Some timber panelling is present on the stair and landing. A pilastered and architraved round-arched opening is on the 1st floor landing. The remainder of the interior is now largely open plan, featuring modern additions and a mezzanine floor.