Trenethick Barton Farmhouse Including Rear Courtyard And Walls And Gateway

Trenethick Barton Farmhouse is a large and architecturally significant farmhouse of probable 16th-century date, built on the site of and possibly incorporating parts of an older house. It was built by the Hill family and underwent extension and remodelling throughout the 17th, 18th, and 19th centuries. The building is constructed of granite and killas rubble walls with granite dressings, and has steep asbestos slate roofs with gable ends, three of which are finished with granite copings. The roof structures include 16th and 17th-century granite ashlar axial, gable, and lateral stacks, with cast-iron ogee-section gutters.

The overall plan is a large, slightly irregular U-shape. The principal front range includes a through passage positioned towards the right, fronted by a two-storey porch. To the left of the passage is a large hall with a front lateral fireplace. A stone straight-flight stair in a projection at the rear right-hand side of the hall is approached from the passage. The parlour, under a cross roof, occupies the left side; a probably 17th-century inner parlour or buttery sits within a small axial wing at the far left, and a large service room lies to the right of the passage at the lower end. Above the service room is a large chamber with two closets at the front and a window bay between them. The rear wings are probably 16th and 17th-century service ranges built on the site of earlier wings. The left-hand wing was extended or remodelled in the 18th century; the other wing was partly rebuilt or refaced in the 19th century. The first floor of the left-hand wing was once approached by a stone stair, now blocked in and hidden, possibly from the rear courtyard, suggesting it may have formerly been a first-floor hall or servants hall.

The exterior presents two storeys with an irregular eight-window south front. The principal 16th-century front features a gable-ended two-storey porch to the right of centre, a two-bay hall front to the left of the porch, a gable-ended parlour front on the left, and a lower-end front on the right. The original door and window openings survive on this front, with mullioned windows and hoodmoulds retaining most of their mullions. The porch has a central four-centred arched doorway with hoodmould and a complete three-light window, with a coped gable above. The Hill coat of arms appears over the doorway. The inner doorway has a four-centred arch and retains an original oak door. The hall front has a four-light principal window on the left with the king-mullion missing but other mullions surviving, and a two-light window on the right with its mullion removed. Two three-light first-floor windows are positioned approximately above the ground-floor windows; the left-hand window is complete. The parlour front has a four-light window with the king-mullion removed and a complete three-light window above. The front of the lower end has a very wide six-light ground-floor window with a central king-mullion, and above are two three-light windows flanking a two-light window at a higher level, with a coped ashlar gable above. All windows in this section are complete. The masonry here is banded with alternate granite ashlar stretchers and rubble bonding courses, and is probably later than the rest of the front, likely built forward in the late 16th or early 17th century. At a later date the right-hand corner, originally an angle, was built up to align with the front windows and the return wall of the gable end. Set back from the main front at the far left is a single-window front of a 17th-century wing with original square 17th-century windows without mullions; the ground-floor window is rebated for probably a former shutter. The left-hand return wall of the parlour has a complete probably 17th-century three-light window.

The rear wall of the front range includes a four-light hall window; a four-centred arched through-passage doorway; a narrower four-centred doorway above (perhaps indicating a former rear porch); two stair windows; and a cellar doorway, all now contained within a 20th-century axial passage extension. The left-hand wing, on its east courtyard front, has a probably 17th-century segmentally-arched chamfered doorway towards the left; a window and blocked doorway at the stair position farther left; some blocked pigeon holes under the eaves; and 18th-century remodelled walls on the right. The rear of the left-hand wing (west wall) has a four-window 18th-century front of a cottage on the left and a 17th-century wall on the right with a 17th-century single-light round-headed window on the first floor. In front of the right-hand side is a studwork wall (now under a later lean-to) containing a resited 17th-century ovolo-moulded four-light window with holes for central stanchions for each light. The inner courtyard (west) front of the right-hand wing has two small 17th-century chamfered granite window openings approximately midway to the first floor, and two wide blocked openings with wooden lintels on the right, these openings appearing to be the same size as the reused 17th-century wooden mullioned window.

The east front of the right-hand wing has a slate-hung gable on the left with two probably 17th-century chamfered openings lighting the attic; a 17th-century rebated window lighting the first floor; a small 17th-century stair window; and another 17th-century chamfered window to the ground floor towards the left. Joints indicate an infilled corner on the left, and unaligned ground and first-floor joints to the right of the gable end suggest the rear wing was rebuilt on an older site in the 17th century. Immediately right of the gable end is an 18th-century two-light window with horizontal glazing bars and leaded panes. Under the eaves towards the right are two resited family crests, the Hill crest and another crest with detail resembling a spoked wheel. At the rear of this wing is a small 17th-century round-headed closet or stair window.

The interior remains largely unaltered since the 18th century and retains many 16th and 17th-century features. The hall has a probably original coffered ceiling covered with good 18th-century plasterwork. The parlour and the room behind have probably 16th-century chamfered and stopped axial beams aligned with the front range. The entry chamber over the parlour and the chamber over the entry and part of the hall have 18th-century plaster cornices. The chamber over the lower end has four-centred arched granite doorways into the closets from the window bay at the front. In the room underneath, these closets are carried on two chamfered granite piers. Behind the lower-end rooms is a circa late 17th-century stair with heavy turned balusters to the lower flight. Several 18th-century panelled doors are present throughout. 16th or 17th-century chamfered fireplaces are found in the hall (front wall), the chamber over the entry (rear wall), and over the parlour (others may be blocked in or in rooms not inspected).

The oak roof structure over the hall and over the lower end is 16th-century with chamfers under the lower parts of the truss blades and under the cranked collar. There are sockets for threaded purlins, with one original purlin in situ over the hall. The trusses over the hall have curved feet and show no trace of smoke-blackening. Other roof structures were not inspected. There is a probably 16th-century shouldered-headed oak doorway between the front and second first-floor rooms of the left-hand rear wing.

Trenethick was held by the Seneshalls in the Norman period. Walter Seneshall, a member of this family, was Member of Parliament for Helston in 1377. The Hill family, who were assigned Trenethick in 1392, adopted the arms of the Seneshalls. The Hill family sometimes adopted Trenethick as their family name.