Bank of Ireland, 43-47 Main Street, Larne, Co Antrim, BT40 1JE

Built in 1933 to the design of the Dublin architect A.G.C. Millar, this is a fine example of Art Deco style in architecture, a style that remains relatively uncommon in Northern Ireland. The building demonstrates the distinctive proportions and ornamentation characteristic of Art Deco, and is particularly important because its interior, notwithstanding some changes, retains its characteristic detailing.

The structure is a flat-roofed building of two and three storeys, with its main entrance facing north. The entrance front is symmetrical, comprising a three-storey central block flanked by two-storey lower wings. The central block is three windows wide at upper floors and topped with a flat roof with a crenellated parapet set back slightly from the line of the main wall on the front and sides. The walls are rendered in smooth cement, lined and blocked, and painted cream.

The windows to the upper floors are rectangular metal frames, each comprising a fixed light beside a side-hung casement with transom lights, including one top-hung transom light. The windows sit in white-painted rectangular vertical recesses. Between the heads of the first-floor windows and the cills of the second-floor windows runs a painted metal panel of repeated lozenge motifs in Art Deco style.

The ground floor of the central block steps forward slightly and contains a large three-light metal window with broad mullions, all painted white. This comprises a large central rectangular fixed pane with a rectangular bottom-hung fanlight, with smaller fixed lights and similar fanlights on each side. Below the central and left-hand fixed panes are moulded rectangular metal panels; the panel to the right has simplified moulding and contains a night safe. A fluted frieze band runs between each fixed pane and its fanlight. Above the ground-floor windows is a full-width frieze panel containing the name "Bank of Ireland" in non-original letters. Below the ground-floor windows is a stepped concrete plinth in two stages, one stage painted mauve and the other painted brown.

The flanking two-storey wings step forward slightly from the central block, both symmetrical in design, with flat roofs and step-form parapets set back slightly to the front and sides. Step-form buttresses mark each extremity. Each wing has one window to the first floor, a rectangular metal frame divided into six panes comprising a fixed light with flanking side-hung casements below corresponding top-hung vents and a fixed light, set in a rectangular moulded recess with a projecting concrete cill.

Below the window of each wing is a large rectangular doorway set in a rectangular moulded surround. The doorway to the left is the main entrance to the bank: a pair of rectangular double doors of varnished hardwood, each leaf three-panel, set between moulded hardwood surrounds, with a rectangular fanlight above. The fanlight is subdivided by arrow-pattern metal grilles in Art Deco style, painted white. The original hexagonal brass door knob and Art Deco-style brass knocker survive. Three steps lead to the front door: concrete at the base with two moulded granite steps above. The doorway to the right has what appears to be a four-leaf folding door in varnished hardwood, panelled, set below a hardwood head, with the sides of the doors flush behind stepped concrete surrounds and a metal-grilled fanlight over, as on the other wing. A concrete ramped approach leads from the pavement to the doors; this originally led to a garage for the bank manager. Above the window of each wing modern bank motifs are displayed, with various modern light fittings attached to both wings and the central block.

The east elevation comprises the three-storey side of the central block with the side of the two-storey wing projecting below, incorporating a set-back. The side of the wing is blank, with a smooth cement-render finish painted cream and a flat roof with square-section cast-iron gutter. The side of the central block contains one window centrally positioned, a timber sliding sash, vertically hung, 1 over 1, with horns. At the left-hand extremity is a circular-section cast-iron downpipe; at the right-hand side is a step-form chimney with three pots, with a step-form crenellated parapet returning from the front façade. To the left of the chimney the roof is flat with a square-section cast-iron gutter. Extending from the left-hand extremity of the projecting wing is the side wall of the rear basement storey, finished with dry dashing of white pebbles and chippings. To the left of this is a concrete board-marked boundary wall terminating in an iron door to the rear yard. Modern steel spiked railings surmount the basement storey and the east boundary wall.

The south or rear elevation shows the three-storey central block with two-storey wings, all in the same plane, with flat roofs and square-section cast-iron gutters. Circular-section cast-iron downpipes at each extremity of the central portion have rectangular hoppers; a similar downpipe without a hopper serves the right-hand wing. The walls are smooth cement-rendered and painted grey. Centrally positioned is a full-height rectangular chimney breast to the central block, projecting above eaves height and finished with step-backs all round, surmounted by pots.

The arrangement of windows to the rear elevation is asymmetrical: two to the second floor, four to the first floor, and four to the ground floor. All are rectangular timber sliding sashes, vertically hung, 1 over 1, with horns, and have projecting cills. Horizontal iron bars are fitted to the ground-floor windows. At the base projects a flat-roofed single-storey basement with cast-iron downpipes from the main block extending across its roof and taken down beyond the basement block. The basement has a square-section cast-iron gutter and felt roof covering. A concrete yard at the rear is bounded by rendered walls to the south and west.

The west elevation is largely obscured by an adjoining building, but upper portions are visible: the side wall of the central block is a cream-painted blank wall with a flat roof and square cast-iron gutter. A circular cast-iron downpipe is present; to the left is a chimney with a step-form top surmounted by three pots. To the left of the chimney, the left-hand extremity of the central block has a crenellated set-back parapet returning from the front elevation. The side of the wing is similar to the left-hand portion of the central block but with a plain parapet and a chimney projecting forward.

The building stands in the main street of the town, facing directly onto the pavement. It is abutted to the west by a lower two-storey shop of entirely modern design and materials; to the east is an empty plot.