Vandals have wreaked havoc at the former home of Lord Ashton in Lancaster as talks continue on its future.
Ryelands House at Ryelands Park has been targeted for "unbelievable vandalism", said a Lancaster city councillor.
Councillor Sandra Thornberry said over the past few weeks the house was "constantly being damaged by vandals" with "a sea of broken slates at the front" of the premises caused by "children up on the roof, snatching the slates and throwing them".
Speaking at a recent Lancaster City Council meeting, Councillor Thornberry also said that "boarded up windows were being pulled out" and repairs were having to be made.
"The cost of trying to keep the house going and sustainable is really worrying," said Councillor Thornberry.
"It is important that things move fast on Ryelands House."
Ryelands House was the home of James Williamson, Lord Ashton, businessman, philanthropist and politician, known for his lino-making empire of factories on St George's Quay.
He died at Ryelands House in 1930.
In 2023, the building was boarded up after tenants moved out at short notice.
Councillor Caroline Jackson, Lancaster City Council leader, spoke at the meeting on July 23 in response to the concerns.
She said the council was looking to see if they could work with "a community partner" on Ryelands House.
"It's sad to hear that more items have been broken and vandalised," said Councillor Jackson.
"We need somebody in there as soon as possible."
A Lancaster City Council spokesperson said they are working with a provider with the aim of re-opening the building and a decision is expected soon.
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