Vehicle store and workshops at Merthyr Mawr House

The vehicle store and workshops at Merthyr Mawr House is a roughly square building with two lower wings on its left side, arranged one behind the other. It is constructed of coursed tooled stone and has slate roofs. The roofs of the vehicle shed and the rear wing are hipped, while the front wing features a gabled roof. The vehicle shed has double sliding boarded doors at the front, and its right side wall is made of rubble stone. The front wing includes a full-height boarded door at the front. The rear wing is wider and has a full-height opening on the left side, along with an overgrown stack at the rear. The rear wall is made of snecked stone and has shallow buttresses, forming part of the boundary wall. The building was not inspected at the time of the survey in May 1998.