The name, hengastell, may refer to an Iron Age hill-fort on the site. The oldest part of the present house is the north-east wing, of about 1840. In 1863 the industrialist C. R. Vickerman acquired Hean Castle. He employed the Manchester architects Pennington and Bridgen to rebuild the house in 1875-6. The house was enlarged in 1926 by the addition of a north-west wing in similar style.
There is a main range of Victorian-Tudor buildings in an ambitious style which extends east/west. The outline in both plan and elevation is irregularly composed, but the east half of the main south front is advanced for extra emphasis. There are octagonal turrets at the corners and a high tower in a central position set back from the front. The parapets are all crenellated. There are return wings at the east and west and a rear service range.
The main building is of two storeys, in a masonry principally of small regular rock-faced courses of a red stone brought from Runcorn. All the stone dressings are in a lighter sandstone. A darker stone is used for aesthetic variation in bands and in a battered plinth beneath a string course at ground storey window-sill level. All the roofs are concealed behind parapets. The windows throughout are dressed in a lighter coloured sandstone and are glazed in plate glass.
For the duration of the War the house was occupied by a school evacuated from Wandswsorth.
