Aberdare Hall including attached NE wing at rear

Aberdare Hall is a Jacobean style hall of residence of three storeys with an attic, comprising seven bays. It is constructed in brick with terracotta dressings, has a tile roof behind coped gables, and brick chimney stacks.

The symmetrical front elevation features mullioned and transomed windows with moulded drip stones, grouped under three linked Flemish gables with open pediments and apex obelisk finials. The lower storey has a deep cornice with a billet frieze. The central doorway is embellished with terracotta detail, including rusticated Tuscan half columns on square bases and a terracotta entablature crowned by obelisk finials. The entablature carries a relief inscription recording the date of the building and the founding of the University College. The doorway itself has a round arch with continuous egg-and-dart moulding and keystone, with double panelled doors and a leaded overlight featuring heraldic stained glass.

Flanking the doorway immediately are 3-light windows. Beyond these are 2-storey 3-light bay windows, with double transoms in the lower storey and open strapwork parapets. On the outer sides of these bays are tall 3-light windows with double transoms. The middle and upper storeys have windows similar to the lower storey, with a 3-light window above the doorway flanked by 2-light windows. In the upper storey, above the bay windows, 3-light windows open onto balconies. The attic has 5-light mullioned windows in each gable, with the central window framed by Ionic pilasters.

The left side wall, which faces Queen Anne Square, extends seven windows and features a deep cornice between the lower and middle storeys, continuous with the front. Two-storey canted bay windows with openwork parapets flank a central 3-bay loggia below the middle storey balcony. The loggia has terracotta detail including Tuscan columns with keyed arches, an open central bay, and pierced strapwork balustrade to the outer bays. Inside is a boarded door with strap hinges on the left side under an elliptical arch, with a 2-light window above, and a 2-light window to the right with double transom. The balcony has an open strapwork parapet.

Flanking the 2-light double transomed bay windows in the lower storey are two 2-light double transomed windows to the left and a similar window to the right. The middle storey has two 2-light windows opening onto the balcony, a single-light window to the right, and two 2-light windows to the left of the bay window. The upper storey has a similar arrangement, with 2-light windows opening onto the balconies of the bay windows. A central shaped gable with obelisk pinnacle has a 5-light mullioned attic window with Ionic pilasters similar to those on the front. Behind the parapet are two flat-roofed dormers. At the left end is an added single-storey projection continuous with the elevation, which has a 2-light double transomed window with brick dressings.

The right side wall is plainer. It has 2-light windows in the middle and upper storeys with plain mullions. To the right, the wall is lower, extending only two storeys behind which is a small open courtyard. Beginning at the left end, the wall features a 2-storey canted bay window, then a doorway with side and flanking lights in a surround with pilasters and pediment, below two upper-storey windows. A second 2-storey canted bay window follows. Further to the right, the lower storey has an inserted window, two 2-light windows, a doorway with mullioned overlight, and a 2-light window. In the upper storey is a 2-light window above the doorway, a 3-light window to its left, and at the right end a 3-storey projection with a linking bridge to a wing added in the 1930s. This wing has brick-mullioned middle and upper storey windows above an earlier terracotta-mullioned lower-storey window. The rear has brick-mullioned windows to projections added in the early twentieth century. Set back at the right end is the north end wall of the original building, which has a single-storey projection above which is an enclosed bridge to a detached wing built in 1963. Otherwise this elevation retains terracotta-mullioned windows and a 5-light attic window.

On the left (north-east) corner of the rear is a 5-bay two-storey brick link to a wing of 1938-40. The bay at the west end has a round-headed arch to a through passage. The remaining bays constitute an arcaded cloister with round-headed arches, with a similar single bay to the return at the east end. The upper storey has replaced windows. The detached 6-bay brick wing has French doors to a library in the lower storey, and replaced middle and upper-storey windows with sill and lintel bands. A further bay is set back at the left end.

Internally, the entrance vestibule has three arches leading to rooms at the rear and to the stairway, which has turned balusters. To the left of the entrance are a common room and dining room. The common room at the front has two fireplaces with canopied wood surrounds, strapwork mantels and Ionic columns. Between the common room and dining room is a wooden screen with strapwork pilasters. Offices occupy the lower storey on the right side of the entrance.