Having done that, they then bulldozed the rubble into the house's duck pond, in order to completely remove all signs that any such thing had ever existed.
This is of course one of the great architectural scandals of Sheffield and would never be allowed today.
Lees Hall was a three story, triple gabled structure but all that remains of it now is the name - which lent itself to the neighbouring Lees Hall golf club - a bit of rubble and the above ditch which is the last remnant of the duck pond. Up until a few years ago, even that was lost but it was exposed during a clean-up of the site, meaning we can at least have a tantalising glimpse of what was once there.
That may be a picture of Lees Hall as it is now but pictures of it shortly before its destruction can be found at Picture Sheffield.