Late 16th / early 17th century with additions of 1660; enlarged 18th century and finally remodelled Orphoot, Whiting & Bryce, 1925. 2-storey and attic, L-plan towerhouse to SW with two 2 and 3-storey and attic additions of differing dates to E. Single and 2-storey ranges adjoining and forming open courtyard. Piecemeal whinstone construction concealed by cream-wash harling; sandstone dressings and margins. Chamfered arrises to earlier windows.
N (PRINCIPAL) ELEVATION: irregularly fenestrated 2-storey and attic. 5-bay ground floor with remodelled (circa 1920) stone entrance door to 4th bay incorporating Hay family armorial plaque above, stones to flanks with a wrought-iron dog (right) and cat (left); 3 regularly placed windows to left and one to right. To 1st floor, 3 irregularly placed bays with small square window to upper right of entrance door; tourelle in upper left re-entrant angle. To right, projecting gabled bay with square attic window; adjoined at lower levels by W range (see below); to left return (forming re-entrant angle with main house), former main entrance door from L-plan tower house with moulded architraved surround and incised date of 1730, Hay family armorial panel inserted above (post 1660); single window to 1st floor.
S (REAR) ELEVATION: to left, 2-storey, 3-bay range with extra window to left of 3rd bay at 1st floor level and at attic level; to centre, 3-storey 2-bay stepped range with arched door to ground floor left. To right, multi-bayed, 2-storey elevation with timber and stone conservatory at ground floor in-filling former terrace below projecting balustraded loggia at 1st floor; attic dormer to above left.
E RANGE: W elevation comprising irregularly fenestrated, multi-bayed range rising from single storey at left to 2-storeyed central gable; irregularly fenestrated 1?-storey range to right with stone surrounded entrance door and stone wallhead dormer breaking eaves; adjoining main house to right return; to left return, gabled end with 2 stepped doors; to right, single bay lower addition with window. E elevation comprising advanced canted bay outshoot with regular fenestration, to right return, tall narrow stack with irregularly placed windows to both storeys right; to centre of elevation, 2-storey, 6-bay with gable rising above central bays; to right, single storey with single window to left.
W RANGE: E elevation comprising recessed single storey, irregular 6-bay range adjoining main house to left and rising into 2-storey 6th bay; corbelled 8-hole dovecote in re-entrant angle. Timber entrance door to 4th bay with small projecting ledge window to upper right; 3 bays to left and single bay to right; to 6th bay, gabled end with door at 1?-storey accessed by flight of random rubble and stone stairs with wrought-iron handrail, gablehead stack rising at apex. To right return, small window off centre right with wrought-iron grille; central window to gablehead. W elevation comprising 1?-storey gable to left with sliding timber doors to ground and paired windows to ?-storey; single storey to centre of elevation partially concealed by flat-roofed store with high stepped chimney flanked by windows to right. Irregularly fenestrated 2-storey and attic main house adjoining to far right, gable rising to extreme right.
9 and 12-pane glazing in timber sash and case windows; some 2 and 4-pane glazing to lesser courtyard windows and single fixed pane glazing. Pitched grey slate roof with metal and stone ridging; small louvred roof ventilators surviving to courtyard wings. Painted cast-iron rainwater goods with decorative hoppers.
INTERIOR: thick internal stone walls with some early door surrounds. A fireplace from the former kitchen (now main entrance) is found in the main hall. Much fine wrought-iron work survives, including stair rails, garden gate and window grills. Integral corbelled 8-hole dovecote in re-entrant angle of W range.
WALLED GARDEN: whinstone rubble walls adjoining to E elevation of E wing and enclosing square-plan former formal garden; doorway to NE corner with lintel incised 1729.
Statement of Special Interest
Haystoun was the heart of a great old estate that projected eastwards to the border of the parish; the old mansion house (incorporated into SW angle, 1st stage of work) of the Hays of Haystoun stands with its farm steading and offices at the mouth of the valley of the Glexsax burn. It had belonged to the Hay family for centuries. As John Hay, the third baron, married twice, his 'second' family succeeded at Haystoun. By 1635, the lands of Henderstoun, Glensax and Newbie had become part of the estate. The house was extended to the east (2nd stage of improvements, towards the late17th / early 18th century) by the addition of a "new kitchen". In 1762, Dr James Hay (a physician in Edinburgh) succeeded his father. His wife was a daughter of Campbell of Greenyards and together they had 2 sons who both lived near by; Adam in Hay Lodge and John in King's Meadow (now Kingsmeadow House, listed separately). Haystoun remained Dr Hay's principal country residence, although his main address was New Street, Canongate. He further improved and extended the property (again to the E); this 3rd stage of improvements saw a new staircase in the old tower house and a dovecot on its exterior. His maiden sisters, Miss Betty and Miss Alice - both accomplished wool spinners, also lived in Haystoun. He revived the Smithfield baronetcy in 1805 and in turn passed it to his son and heir, Sir John Hay who resided at Kingsmeadow House. The maiden aunts returned to live in Edinburgh and the house became the residence of the factor of the estate. At this point, additional ranges of buildings were added (4th stage) and Haystoun turned to a more agricultural usage. The building was remodelled in 1925 and since then has ceased to be the residence of the factor but become, once again, the principal residence of the owner. A farm and remains of a mill stand to the NW of the house, which is accessed by a stone bridge over the Haystoun Burn. A walled garden stands to the E of the house and courtyard range.