The Pumphouse (also known as the Engine House) has three levels; the basement, the ground floor and the gallery. The machinery passes through the three levels and is supported by cast iron columns and brackets. The exterior walls are red brick with cornerstones of basalt. The steps and windowsills are also basalt. Inside, the walls are plastered and finished with a moulded skirting and dado to the height of 1.35 m. The timber flooring and other joinery is all of the best quality heart kauri. The staircase has moulded banisters and a moulded, polished handrail.
The Boiler House is adjacent, and an interesting feature is the exposed timber bracing in the roof. The brick arches over the doors have a basalt keystone in the centre. Originally the roof of this building was made from slate tiles but it is now corrugated iron. The boiler house chimney was removed in 1948.
William Errington. 1877. The Western Springs Pumphouse and Boiler House 1877, 1964.311. The Museum of Transport and Technology (MOTAT).