Built almost entirely out of stone, brick and metal, the Brandon Armoury is surrounded by a large brick fence for security. The late Gothic Revival structure rests on a stone foundation and all the exterior walls are covered in brick. Other features include a metal gable roof complete with a battlement, tower, and ventilator. The exterior of the building is decorated with a brick belt and has a recessed entrance. An inscription stone shows the date of construction, and a monumental stone rests on the front lawn.