It measures roughly 7.5 metres by 3 metres, sub-rectangular in plan, and its walls were never made of stone. What marks it out on the archaeological record is a pattern of postholes and a slot trench, the kind of evidence left behind when a timber-framed structure rots away over centuries, leaving only the voids and channels cut into the earth to receive its uprights and sill beams.

The building came to light through test-excavation carried out under Licence no. 06E0799, the findings of which were reported by Frazer in 2007. Eight postholes were identified, along with the slot trench, together describing the footprint of the structure. Its orientation runs roughly west-northwest to east-southeast, a detail that can sometimes hint at function or period, though the notes do not draw firm conclusions on that point. To the south of the site, there is what may have been a historical stream route, which would have made the location practical for any number of uses, whether agricultural, domestic, or industrial.

Because this is a subsurface site with no visible above-ground remains, there is little to see at ground level without prior knowledge of its location and the excavation record. The area around Grange in south County Dublin is broadly rural in character, and the site sits in the kind of quietly unremarkable landscape that tends to conceal earlier layers of settlement and land use. Anyone with a particular interest in early building techniques or the archaeology of the Dublin hinterland would find the published excavation report, cited by Frazer, the most rewarding starting point for understanding what was actually found here.