A blaze broke out in the roof of a cottage in warden-assisted accommodation.
The cottage, one of 10 run by the Hand Sisters Homes Charity Trust in Station Road, Cropston, is unoccupied and undergoing refurbishment.
Fire crews attended the incident, which happened at about 9.30pm on Saturday.
Flames were coming through the roof of the property, built in 1928 as homes for retired teachers and nurses by the charitable organisation of the Hand family, who owned slate quarries in Swithland.
A couple in a neighbouring cottage left their property while firefighters tackled the blaze.
Warden Joan Chambers, whose cottage adjoins the fire-damaged property, said: "The alarm system, which is connected to my cottage, went off and I thought it was a burglar.
"I saw the smoke and flames and went to get the residents out who live on the other side and called the fire brigade. It was all over by 11.30pm.
"They were very quick to respond and have been amazing, even coming back this morning to cover the roof with tarpaulin."
The 10 cottages, set back off Station Road, were built and endowed in memory of Sarah and Henrietta Hind, of Ibstock, the daughters of Henry Hind, owner of Brant Slate Quarries at Swithland, in 1928.
The cause is believed to have been an accidental electrical fault.
