A Grade II listed building is to be sold to raise funds for vital repairs to Willersley Castle.
Derwent House is located within the grounds of Willersley Castle, in Cromford, and has been used as offices since the 1980s.
Now the owners of Willersley Castle, Christian Guild, have won planning permission to turn Derwent House back into a home.
The purpose of the scheme is to allow Derwent House to be sold to raise funds towards a complete overhaul of Willersley Castle roof, which is in urgent need of repair at an estimated cost of more than £425,000.
Money from the sale will go towards repairing the roof of the castle, which retains its original format and materials that have deteriorated over 220 years, leaked and caused some internal damage.
Willersley Castle, the former home of the Arkwright family, is set in the heart of the Derwent Valley World Heritage Site and is the jewel in the crown of the Cromford conservation area.
The castle, set in 60 acres of grounds, has been a holiday centre since 1928, apart from being a Salvation Army maternity hospital from 1940-46 when more than 4,000 babies were born there.
Derby firm Planning and Design Practice worked on the planning application to Derbyshire Dales District Council with the castle’s owners.
Jon Millhouse, of Planning and Design Practice, said: “We are delighted to be able to use the planning system creatively to help preserve a famous and important part of Derbyshire’s heritage.
“Derwent House is a gem, part of the Arkwright story, and now has the opportunity to be restored to its original use.”
Derwent House, which has three reception rooms and five bedrooms, is thought to pre-date the castle, with the rear believed to be the remains of a stone-built farmhouse.
It is likely to have formed part of what was Willersley village, prior to its reorganisation by industrialist Sir Richard Arkwright.
The three-storey frontage was built around 1800, shortly after the castle, and has detail to its construction which contributes to the setting of the castle.
Before it was converted into offices in the 1980s, Derwent House had always been used as a home.
Planning and Design Practice also secured planning permission for the change of use of a former stable block within the curtilage of the Grade II* listed castle to provide alternative offices.
As part of the scheme, Christian Guild will pay a sum towards providing low-cost housing in the district.