House, now 2 dwellings. Low Startforth Hall dated 1633, probably incorporating earlier fabric, refenestrated on south and 2nd floor added c.1750; mid-C19 east extension is now Low Startforth Hall East. Old part rubble with roughly- shaped quoins and cut dressings; C19 part roughly-squared stone with tooled stone east front and tooled-and-margined quoins; graduated stone slate roof. Double-span plan. South elevation in 2 sections: Left part 3 storeys, 2 bays; 3-light Gothick casements in raised and tooled surrounds with lintels (except top left); let into wall between lower windows a shaped slate panel with quotation from Horace, 'Hoc erat in votis: modus agri non ita magnus,/Hortus ubi et tecto vicinus iugis aquae fons/Et paulum silvae super his foret' (This is what I prayed for: a plot of land not too large, containing a garden and near the house a fresh spring of water, and a bit of forest to complete it); still very appropriate: Gill Beck flows through the garden. Left gable coped on moulded kneeler; stepped and corniced ridge and left end stacks. Right part same height but 2 storeys, 1 wide bay; similar 1st floor window above canted bay with plate-glass sashes; roof hipped to right. Right return (east front) shows three 12-pane sashes above C20 extension. Left return shows large projecting stepped stack-with 2 small chamfered windows on right, the upper blocked; line of steeply-pitched Cl? roof visible. Rear elevation: Old right part has restored chamfered doorway on left with re-set slab, dated 1633 with initials AA and IC above; scattered small windows, with fancy glazing, all in chamfered surrounds, that on 1st floor centre with head dated 1633. Left part has part-glazed 6-panel door in Tuscan doorcase and similar fenestration. Interiors: Low Startforth Hall ground-floor east room has large fireplace with flat-pointed arch in moulded square frame; heavy stop-chamfered ceiling timbers. West room has C18 fireplace and chamfered beams. Fielded-panel doors in panelled reveals and panelled segmental arches to lobby. Carved front door, probably from Streatlam Castle. Open-well cut-string stair with column-on-vase balusters, square newels and steeply-ramped moulded handrail, continued up to 2nd floor. Thick spine wall might be pre-C17. Low Startforth Hall East: Elaborate plaster cornices and ceiling rose. Carved chimneypiece and panelling brought from Streatlam Castle. Lower 2-storey part of Low Startforth Hall in former stable range to west, is not of special interest. The adjacent Low Startforth Close and West Mews, previously included in the listing, have been much altered and are not of interest.