What sets Laburnum Cottage on Harmony Avenue apart is its age. According to a 1996 property supplement in the Irish Times, it dates from the late seventeenth century, making it one of the earliest surviving domestic structures in the area, a period when Donnybrook was still a village well outside the city boundary rather than the built-up suburb it is today.

The late seventeenth century was a period of considerable upheaval and resettlement in Ireland, following the Cromwellian land confiscations of the 1650s and the subsequent Restoration. Suburban cottages from this era are rare survivals precisely because they were modest and utilitarian, built without the ambitions of a great house and therefore unlikely to be preserved by later generations with an interest in architectural heritage. Laburnum Cottage's longevity is therefore something of an anomaly. In 2003, when archaeological testing was carried out in connection with a proposed extension to the building, excavators found no archaeological material of note, a result that, while unremarkable on its face, at least confirms the site was not disturbed by earlier buried remains. The findings were documented by M. Mc Quade and published in 2006.

Harmony Avenue is a short residential road, and Laburnum Cottage is a private dwelling rather than a heritage site, so there is no public access. The interest lies less in visiting than in knowing it is there at all, a seventeenth-century structure absorbed so thoroughly into an ordinary street that it would be easy to pass without a second glance. For those with an interest in Dublin's early suburban history, the surrounding area rewards a slow walk: Donnybrook retains fragments of its village character around the old church and the Dodder river, and the contrast between those remnants and the encroaching city makes the presence of a late-1600s cottage feel less improbable than it might otherwise seem.