The date is set into a breakfront, a slight forward projection of the facade that draws the eye upward through a tall round-headed window to a bellcote above. The rest of the entrance front is random-rubble sandstone, left exposed, while the remaining walls are rendered, giving the building a quietly two-faced quality. Flanking the central doorway are smaller doors set beneath blind window opes, openings that have the shape of windows but no glazing, purely decorative gestures that lend the facade a sense of symmetry and occasion.

The story of how this church came to exist is compressed into a single sentence recorded by Samuel Lewis in his 1837 Topographical Dictionary of Ireland, written when the building was still just a plan. Lewis described it as a small plain building about to be rebuilt on a site given by one Jas. Hennessy, Esq. That earlier chapel, the one being replaced, appeared on the 1842 Ordnance Survey map as the Old R.C. Chapel on Ross Street, roughly 150 metres to the east, and no longer survives. The new church completed in 1839 was therefore a step up in ambition, something reflected in its classical reredos, the decorative screen behind the altar at the south-west end, and the gallery that was installed at the north-east end, though that gallery was later replaced during a refurbishment in the mid-1990s. The interior is lit by five round-headed windows on each side wall, the repetition giving the space a calm, even rhythm that sits comfortably with its modest architectural pretensions.