St Louis Grammar School, 151 Newry Road, Kilkeel, Newry, Co Down, BT34 3ET

St Louis Grammar School is a prominently sited two-storey, multi-bayed building with a tower, constructed in two phases during the inter-war years of the 20th century. The building is of interest because of its association with the religious order of St Louis.

The main elevation faces north. The first phase of construction, occupying the west end, includes a three-stage rectangular tower now positioned at the middle of the entire block. This phase is built of regularly coursed concrete blocks cast to simulate rock-faced stonework, with strap pointing throughout. The concrete block quoins are plain, and there is a projecting chamfered basecourse. The main entrance is set within the tower, with a pair of modern six-panelled doors with fixed side panels and a plain rectangular overlight positioned on the tower's right (west) cheek. All openings have chamfered concrete jambs and heads. The upper floors of the tower each have a pair of 6/6 sliding sash windows; those to the first floor have been replaced in plastic. The tower's cornice is machicolated, and the roof is steeply pitched and hipped, creating a short ridge, crested with lead finials and finished with ogee cast-iron gutters.

The north elevation of the tower displays an infilled pair of transom windows at ground floor, a pair of 6/6 sashes to the first floor, and a pair of modern casements to the second floor. The left cheek has a 6/6 sash at ground floor, a modern 6/6 sash to the first floor, and a pair of 6/6 sashes to the second floor. On the main block to the right of the tower are six matching openings. At ground floor, each opening (except the most westerly, which contains a single 4/4 sliding sash) holds a pair of large 4/4 sliding sashes set within a single opening. Above each are a pair of similar smaller windows separated by a masonry pier. A narrow 2/2 sash window appears at the extreme left.

A single-storey porch abuts the west opening, constructed with walls matching the main façade and a pitched natural slate roof. It features a pair of 4/4 sliding sashes on its north gable and a door to its left cheek; its right cheek is blank. The west gable of the main block has a raised and coped parapet with a finial cross. A full-height window with a solid panel within it divides the ground floor from the first floor, displaying the arms of the diocese and of the nuns of St Louis. The concrete panel has plain chamfered concrete head, cill and jambs.

The rear elevation is similar to the front but eight openings wide. In the east bay at right is a single-storey porch with a crenellated parapet, featuring a Gothic door on its south elevation and a 1/1 casement on its left cheek. At the extreme right, at the junction with the second building phase, is a single-storey timber link corridor with a shallow flat roof leading to the former convent house to the south. The rear elevation displays pairs of 4/4 sliding sashes at ground floor (each pair within the same opening) and paired 4/4 sliding sashes (smaller and not sharing the same opening) to the first floor.

The second phase occupies the left section and extends ten bays, terminated by an advanced three-bay hipped section set at right angles at its east end. The roof is pitched with natural slate, with ventilators informally positioned along the ridge. The walls are constructed as in the original block with similar dressings but without a raised basecourse. A door appears in the middle bay of the advanced east section. Large steel casement windows, one to each bay on each floor, appear throughout, with those to the first floor diminished in height. The rear elevation is similar to the front.

The entire building is finished with a pitched natural slate roof. Eaves courses project and support cast-iron ogee gutters throughout.

Abutting the east end of the advanced end bay is a post-Second World War three-storey extension of the same height as the adjoining block. It has a flat parapeted roof, grey brick walls, and vertical curtain walling with painted fixed apron panels. Tarmac playgrounds occupy the front of the site.

The school was erected in the 1920s and has been extended on a number of occasions. It was initially run by the nuns of St Louis.