Trewern Mansion

Trewern Mansion is a three-storey house that faces west towards a large forecourt. The exterior is rendered over ashlar masonry and features a small plinth and an oversailing plain parapet. There are small chimneys, one offset to the right of the centre, one over the right side parapet near the front, and another over the left side parapet near the rear. The roofs are concealed with slate. The front range has five windows, with the outer pairs positioned slightly closer together. The windows have recessed exposed frames and an unusual reeded window-frame ornament. The glazing bars on the ground storey have likely been removed for conversion to plate-glass glazing, while the upper windows consist of four panes.

A central tetrastyle porch, featuring plain Doric columns, rear pilasters, and a paterae frieze, leads to the entrance. The doorway has double three-panel doors, sidelights, and a traceried fanlight, designed as a Venetian window.

The rear elevation is symmetrical, featuring outer full-height bows. The centre has three windows, with each bow containing three windows. The left bow includes a small front area with basement windows. The rear also has an oversailing plain parapet. The sash windows match those at the front, but the top storey windows have six panes, while the others have four panes. The joinery of the bow windows is curved. There are two French windows in the centre block, one uniquely constructed with an upper sash.

The interior is arranged around a central entrance hall that opens into a lateral rear hall. It features a cantilevered open-well staircase with nosed treads and a scrolly ironwork handrail. Notable interior details include plaster cornices (with a paterae frieze in the dining room), ceiling roses, elliptical arches on brackets, and six-panel doors in moulded architraves. The drawing room has a chimneypiece with an Adamsesque frieze, a carved tablet, and fluted columns.