Number 25 Eustace Street has been identified by the Dublin Environmental Inventory, Department of Architecture, as a Dutch Billy type building, placing it within a category of domestic architecture that was once extraordinarily common in Dublin but is now so rare that each surviving example is treated as a matter of record.

Dutch Billies, as they are known colloquially, are buildings characterised by their distinctive curved or stepped gable ends facing the street, a form that arrived in Ireland largely during the late seventeenth and early eighteenth centuries, carried across with the influence of Dutch and Flemish architectural fashion. The name itself is thought to derive, somewhat cheekily, from King William III, whose Dutch connections were well known to the citizens of the city he transformed politically. At their height, these gabled facades defined the skyline of Georgian and pre-Georgian Dublin, lining its commercial streets in tight terraces. The wholesale redevelopment of the city across the eighteenth and nineteenth centuries swept most of them away, replaced by the flat-fronted brick terraces that now define the popular image of historic Dublin. What the Dublin Environmental Inventory has done, in logging Eustace Street among its entries, is acknowledge that something older and more unusual survives here, though the precise date of the building's construction remains unrecorded.

Eustace Street itself runs through the heart of Temple Bar, a neighbourhood that has been heavily altered since its 1990s regeneration, making the presence of any pre-Georgian fabric all the more notable. The street is short and easily walked, connecting Dame Street to the north with the area around Meeting House Square. Number 25 is best approached on foot, and the gable form, if visible from the streetscape, is the detail to look for, since the defining feature of a Dutch Billy is most legible at roofline level. The area is busy during the day and evening, so a quieter morning visit gives the best chance to stand back and examine the upper storey without the pressure of foot traffic. No special access is required; this is a building observed from the public street, its significance residing less in any grand interior than in what its roofline quietly suggests about the layers of the city that remain, largely unannounced, in plain view.