One is circular, sitting at the centre of the fort's interior; the other is rectangular and lies towards the southern sector. That pairing, a round hut and a more rectilinear house platform within the same enclosure, is a small puzzle worth pausing over.

Hillforts are enclosed areas, typically defined by earthen banks or stone walls following the contours of high ground, and they appear across Ireland in forms ranging from massive prehistoric constructions to smaller, locally significant enclosures. The circular hut at Earlspark conforms to a building tradition that was dominant for much of Irish prehistory and the early medieval period, when roundhouses were the standard domestic form. The rectangular structure in the southern sector is harder to date on shape alone, since rectilinear buildings became more common in Ireland from the early medieval period onward, but without excavation the sequence of occupation at Earlspark remains open. Whether the two structures were ever in use at the same time, or represent successive phases of activity within the same enclosure, is not something the surface evidence can resolve.