Sennan House, Rostrevor Road, Warrenpoint, Newry, Co Down, BT34 3RT

Sennan House is the right-hand unit of a pair of mirror-image semi-detached villas built around 1860. The two large two-storey houses stand sea-facing in mature grounds on the north side of Rostrevor Road, with their principal elevations facing south and entrances positioned to the side elevations.

The building has a pitched natural slate roof in an L-plan (with the base of the 'L' facing east), featuring moulded advanced eaves and bracketed ogee cast-iron gutters. The left bay gutter carries cast-iron cresting. Stucco chimneys with chamfered bases, moulded caps and yellow octagonal terracotta pots are distributed across the roof—four pots on a shared rendered chimney between the two houses, and two-pot chimneys elsewhere.

The walls are smooth rendered and painted, with a moulded basecourse and moulded platband between floors. Additional thinner platbands sit at quarter and three-quarter height on each floor. All windows feature run-moulded stucco architraves with plain decorative key-blocks. Ground-floor windows are 1/1 sashes (except where noted), while first-floor windows are 2/2 (vertically divided) sashes with segmental heads.

The south elevation is two bays wide. The right bay advances slightly and contains a single-storey canted bay window with moulded and fretted parapet over a blocking course concealing its flat roof, with windows to front and narrow cheeks. Above at first floor is a single window with a stucco roundel in the gable, adorned with keyblocks to the cardinal points. The left bay holds a rectangular single-storey bay with two front windows, narrow blank cheeks, and a swept leaded roof with decorative cresting; a single first-floor window sits above.

The east elevation is three bays wide and contains the main entrance. A single-storey gabled porch with pitched natural slate roof, decorative fretted timber bargeboard on paired brackets, and granite step projects from the central bay. The door comprises two vertical round-headed panels with a beaded muntin, topped by a semicircular headed fanlight and moulded architrave with fluted arris. The porch's left cheek has a 2/2 sash window; the right cheek is blank. The remaining bays each contain a single window opening, with a matching window above the porch. All are 2/2 sashes except the ground-floor left opening, which has a low cill and part-glazed apron below the sash.

To the left of the north gable stands a lower two-storey return, set back slightly from the main block's east elevation, topped by a pitched natural slate roof aligned north-south. The return's east elevation spans four openings wide with rendered walls, platbands at ground-floor cill level, three-quarter height, and first floor. All openings feature moulded stucco architraves and are 6/6 sashes except: the second opening from left at ground floor is a modern timber door with transom light; the opening to its right is a wide window with modern Georgian glazed timber sash; and the second opening from left at first floor is a tiny roundel. A small rendered chimney sits on the return's ridge. The return's north gable is rendered and blank (its central and right portions are abutted by the stable block). The west elevation is rendered and unpainted, with a small modern lean-to at right and a two-storey return at the left end. The lean-to has a chimney stack and shallow artificial slate roof. The left-end return has walls matching the main block, with two six-paned casements on its west wall at ground floor and a 1/1 sash at first-floor south cheek. The remaining section has a two-paned modern window at ground-floor centre, a 6/6 sash at ground-floor left (with a matching window above at first floor) and a 1/1 sash at first-floor right.

A lean-to structure abuts the main block's north elevation, with artificial slate roof and painted cement rendered walls; its front wall contains a modern window.

The stable block stands two storeys, aligned west-east, with pitched natural slate roof and cement rendered walls (painted to north and east only). Its west gable abuts the adjacent extension of St. Leonards. The east gable is blank at ground floor and has a loading door at first floor. The north elevation features a semi-elliptical headed coachway at left (since infilled and glazed with a door) and a door with small cast-iron lattice casement window at right. The south elevation faces into the domestic yard with a ground-floor door at left and a small 1/1 sash window at first-floor centre. A small rear yard enclosed by a rendered wall with gate piers (gates absent) lies to the north and east of the stable block.

The front garden is terraced and lawned.

The house does not appear on the 1859 Ordnance Survey map but is first cited in the 1861 Second Valuation book as unoccupied, indicating construction around 1860. The landowner was recorded as Leonard Watson.

The building is compromised by modernisation undertaken to its partner property.