Horsgate House in Haywards Heath, West Sussex, was built in 1866 by a local banker as a family home and is set on a 1.2-acre site.
In 1990 it was converted into 29 self-contained flats and a one-bedroom bungalow.
Now vacant, the property is being offered with a £1.4m guide price on behalf of Affinity Sutton with scope for commercial or residential development subject to planning.
The auction will be held at the Hotel Russell, WC1, on 20 April.
