Plas Llangattwg

The house is entered from front and rear into a large central stair hall. The full-height dog-leg staircase is on the R (W) side and extends into the rear projection. It is of oak, has a swept handrail, 3 balusters per tread and a substantial round-section newel post. The hall has oak floor boards. The dining room is to the R and the living room to the L of the hall. In the Living Room, the French Doors are below a decorative metal pelmet. There are 2 large arched recesses in the living room. Moulded coving, panelled shutters and doors throughout. From the rear entrance, Tudor-arched openings lead into the stair hall and into the lean-to room behind (S of) the living room. This lean-to room contains Tudor features: a boxed-in cross beam, the timber mullioned window, and part of a curved stone staircase. The interior of the long service range to the S of the W wing contains evidence for fireplaces and beams.

Georgian country house with fine symmetrical front showing Regency improvements. The main block of the house is 3-storey, 3-bays under a hipped roof and with a central pediment and rusticated quoins to the main elevation. Flanking this are two-storey side wings with parapets, concealing lean-to roofs. Staircase turret to rear, along with further ranges. Slate roofs with rendered end stacks and painted roughcast elevations.

The front elevation has a moulded dentilled eaves cornice. The central pediment has a similar cornice and contains an oculus with radial glazing. There is a fine decorative wrought iron veranda of 2-storeys to the front. It is supported on 8 posts composed of narrow strands of iron. There is an iron latticework screen against the wall, presumably for climbing plants. The 1st floor supports a cast iron porch canopy with swept roof and finial. The central front entrance has an ornate gabled doorcase with fluted pilasters, capitals and bases and a moulded cornice. It contains a round-headed doorway containing half-lit panelled double doors with fanlight. The entrance is flanked by square headed French Doors. Each door is of 3-panes with further rows of glazing above and to the sides. The 1st floor has 3 pairs of French Doors. The central pair are narrower and under the iron canopy. The flanking French Doors are like those on the ground floor but without the upper row of glazing. The upper storey has 9-pane hornless sashes, a single central window flanked by paired windows. The side wings are 1-window and have 12-pane sashes to each storey with stone sills.

The W wing continues to the S as a long 2-storey range. The W side has irregularly placed sash windows, four 12-pane sashes to the upper storey and a small 6-pane window. The ground floor has two 20-pane sash windows towards the centre flanked by 12-pane sashes. There is a brick stack to the rear of this range.

The E wing is 2-window with a 16-pane horned sash at the N end and a C16-17 window at the S end, a 3-light casement with timber hexagonal mullions and quarry glazing. The upper storey has two 12-pane sashes. At the S end of the E wing is a porch and panelled door which leads into a rear lean-to, but is no longer in use. The square porch has an entablature supported on 4 columns. Extending S-wards from the door is a random rubble garden wall, with a basket-arched entrance into the rear garden.

The rear is dominated by a full-height gabled stair projection with 12-pane sashes at landing height to the 1st and attic storeys. It is flanked by 2 gabled roof dormers containing multi-pane casement windows. In the lower storey, a door leads into a flat roofed extension. Lean-tos flank the staircase projection. That to the E incorporates part of the Tudor house. Its rear elevation has two 16-pane sashes to the upper storey and a large 5-light multi-pane window below. The lean-to on the W side of the projection is slate hung with a small 4-pane window, but is mainly concealed by the flat roofed, L-shaped extension. At the S end of the flat roofed extension, and abutting the W wing (which has a 12-pane sash to the rear) is a square range with a hipped roof. From this extends a masonry boundary wall.

The S end of the W wing butts a further long range on the same orientation which may be earlier. It is a range of service buildings which included stables, a cart shed and possible groom's accommodation, with a hay loft over. It is of masonry under a slate roof with a large masonry ridge stack. The S end now contains a garage with wood planked doors and 2 further C20 doors. There is also 4-pane window and a 9-pane window. The former hay loft has a raked dormer with wooden shutters. The W wall faces a public footpath and there is evidence for infilling between masonry piers. There are a few small wood-framed windows but otherwise no features.