Thundercliffe, an eighteenth century mansion house with service wings and stable block, set in 22 acres of mixed park land and woodland on the Sheffield/Rotherham border in South Yorkshire celebrated its 20th anniversary as a co-housing institution in May 2000.

The initial participants, the majority of whom still live at the Grange, were mainly local government officers who, together with friends and family, formed the company "Thundercliffe Grange Ltd." to purchase the Grange, a former residential home for physically and mentally handicapped children, from Sheffield Health Authority and to convert it into self-contained flats together with areas for communal use.

There are twelve flats - some occupied by single people the others by families, in total some two dozen occupants ranging in age from 2 to 65. There is no specific ideology which defines the group and every effort is made to preserve the privacy and autonomy of individuals while sharing the benefits (and the work and expense) of the house and its grounds. The land, apart from the kitchen garden and ornamental gardens adjacent to the house, comprises woodland and park land and is managed in such a way as to enhance the habitat for birds, animals etc.The ground floor of the main building provides communal areas such as workshop, dining room and laundry.