Largely product of remodelling for John Henry Vivian whose family owned Hafod Copper Works, dominating the copper industry in Swansea in the C19. Two phases of remodelling; first between 1817 and 1823, after having bought the property being a simple Classical building; the second, which continued until 1837, involved more radical Tudor rebuilding designed by P F Robinson (1776-1858). This London architect was famous for his `Designs for Ornamental Villas" and other pattern book publications. It was renamed Singleton Hall, Park or Abbey, at this time, although there are no monastic associations. Despite remodelling, aspects of the original, octagonal, villa (Marino), begun in 1782 to the designs of William Jernegan, remain. By 1851 stables and coach-house were added and minor works done in 1887 for visit of Prince of Wales. Fire in 1896 resulted in some rebuilding and Singleton was sold in 1919. In 1920 the University College opened on site; some alterations in conversion plus recent removal of tower.

Tudor style mansion, mostly 2-storeys, with complex plan. Constructed of brick and rubble with scribed cement rendered and freestone dressings; slate roofs and tall rendered chimneys, some ornate.

Entrance front has 3-gables, the central advanced and enriched with angle turrets, griffins, pinnacles and foliated stringcourse. Bath stone porch has a 4-centred arch and ribbed plaster vault, and is linked at the corners to two stone sheriffs posts. Windows are mainly cross-frames, there is a splayed bay to centre and later C19 bay window to right. Front retains part of Marino - the semi-octangonal projection to the centre. Each bay flanked by octagonal turrets with crenellated caps, and coat of arms to central gable, below which is an oriel window.

To right is dining-room extension with high gable parapets; this is not shown in a drawing of 1832 but is included in Robins 1837 drawings. Church-like front with cusped ogee-headed windows, crocketed hoods, carved headstops and panelled buttresses, with intersecting tracery to gable end. By contrast the interior of this range has square-headed window openings.

Building steps back to W and has been variously altered and extended in a similar style. Running N/S at the extreme W end is the former orangery ; its snecked rubble front has tall piered parapet and 4-centred openings with small-pane glazing.

Linked to N is a mid/late C19 2-storey gabled house which was built for one of the staff, later the Registrars House and now University offices; snecked masonry and similar window and chimney detail.

N end of Singleton Abbey is occupied by the stable courtyard with an L-shaped range of buildings; rubble with red brick dressings and slate roofs. Former coach house,altered to ground floor, with symmetrical stable block to N with advanced and gabled 2-storey central and end bays; single-storey and attic between with brick dormers. Central square clock-tower with applied black and white detail and iron brackets carrying the bell; projecting chimney to rear with circular stack. S side of courtyard has later C19 elevation to a range backing onto a central light well/courtyard (partly infilled); this area is shown as the Butler's Room on the 1837 plan.
(Source; Cadw listing description) S Fielding RCAHMW 20/10/2005