The building at No. 3a has been identified as a Dutch Billy type house, a style of domestic architecture that was once widespread across Dublin but is now so rare that individual surviving examples are worth recording by name.

The Dutch Billy was a distinctive house type that arrived in Ireland in the late seventeenth century, associated with the influx of Dutch and Flemish craftsmen and merchants who came in the wake of William of Orange's campaigns. The style is characterised by a stepped or curvilinear gable facing the street, a feature that gave these buildings their nickname and set them apart from the flat-fronted terraced houses that would eventually replace them across Georgian Dublin. Over the course of the eighteenth and nineteenth centuries, changing tastes and extensive redevelopment swept most of them away, which makes surviving examples difficult to identify and easy to overlook. It was the Dublin Environmental Inventory, compiled by the Department of Architecture at University College Dublin, that formally recorded No. 3a as belonging to this category, though the precise date of construction remains unestablished.

Because the building sits within the fabric of the south city rather than in any designated heritage zone with interpretive signage, there is nothing to announce its significance from the pavement. Visitors with an interest in early Dublin streetscapes would do best to approach it with some background reading on Dutch Billy typology, since the distinguishing features can be subtle, particularly where later alterations have softened or obscured the original roofline and gable profile. The building is not open to the public as a heritage site; its interest lies in being a fragment of an older city still embedded in everyday use, the kind of survival that repays careful looking rather than formal visiting.