Glandavon is a c.1660 country house in whitewashed roughcast (mostly covered in creeper) with a hipped slate roof and paired bracket eaves. The roof has a centre valley and two big axial three-shaft rendered stacks. There is a two-storey five-window front of timber cross-windows with slate sills and a centre early 19th century 6-panel door with sidelights in an early 19th century timber porch of two Roman Doric columns, pilaster responds, and cornice. The house is to a regular square plan with a centre rear stair projection also hipped. There is an added block in the rear.

The interior, in a Renaissance square plan, is typical of the later 17th century. The staircase is exceptional in scale though relatively crude in detail, open-well, with plain string, square newels, carved finials and pendants, and turned balusters. The two front rooms and parlour have plastered panelled ceilings, with simple mouldings framing the beams. The kitchen has three exposed beams, and the remains of a small stair to the left of the fireplace. Three ornate figured wood doors were introduced from Surrey in the 20th century. Two upstairs bedrooms have similar plastered panelled ceilings, and there is some fielded panelling to the wall to the small centre room.

On the east of the forecourt are two stone early 19th century gatepiers.

Reference: Cadw listed buildings database.