The government body which champions England’s heritage has thrown its weight behind a proposal to secure the future of a 16th century mansion ranked among the country’s most outstanding properties by transforming it into a retirement resort.

Historic England said The Timeless Collection Holdings’ plan to create 35 rental “Luxury Later Living” homes for over-55s at grade I listed Gilling Castle, in the Howardian Hills Area of Outstanding Natural Beauty, is “eminently compatible with the heritage significance of the site”.

Planning documents lodged with North Yorkshire Council state “following years of neglect”, the multi-phase country house, which was previously owned by Ampleforth College, will undergo specialist restoration and repairs “to host, enhance and celebrate the history of the buildings and features on site”.

Remnants of a fortified 14th century manor house survive in the basement of the property built by High Sheriff of Yorkshire Sir William Fairfax in 1571 on top of the medieval walls.

At the beginning of the 18th century Viscount Fairfax of Emley remodelled the interior of the house and added wings enclosing the front  court, work which has been attributed to John Vanbrugh, James Gibbs or Yorkshire gentleman architect William Wakefield.

In the 20th century the house was used by Ampleforth College as a pre-school and saw a new wing fitted out with Robert ‘Mouseman’ Thompson furniture, fixtures and fittings. The school closed in 2018.

Historic England describes the building as “a tour de force of high quality architecture” retaining historic fabric and features from a number of different periods, “each telling a story about how the building has evolved over the centuries”.

The body highlights how its grade I listing places it in the top two per cent of

buildings in the country listed for their exceptional architectural and historic interest, while the extensive grounds are separately designated as a grade II registered historic park and garden.

In the planning papers, agents for the developers said the proposed redevelopment would “renew a key site within the heart of North Yorkshire, to ensure the future of the heritage assets” by creating a “continued revenue stream”.

The documents reveal plans for 24-hour staffing and leisure and social facilities, including a dining room in the Long Gallery, landscaped and formal gardens and improved sporting facilities, alongside Ampleforth golf course and clubhouse.

The development would feature common areas such as the Great Chamber along with sitting rooms to be retained as residents’ common areas for lounge and private bar facilities and rooms devoted to arts and crafts, a cinema and a golf simulator.

In its response to the planning application, Historic England said it was “very supportive of the new use in principle as it is eminently compatible with

the heritage significance of the site”.

Setting out “conditions that could help to ensure the applicant’s aspirations for the site are secured”, a spokesman for the body said it had concerns over the “enabling development delivery model and the need to secure the repair and long-term maintenance of the heritage assets on the site”.

The spokesman said: “The balance between private and publicly accessible spaces (for residents and visitors) both inside and around the Grade I listed building and its registered historic gardens, is an important consideration.

“We are pleased to see the high status rooms in the castle that display historic fabric and features of the highest heritage significance are to be accessible to all visitors.

“We strongly support bringing Gilling Castle and its associated heritage assets back into an active new use compatible with its conservation.

“We welcome the applicant’s commitment to conserving the heritage values attached to this fascinating group of heritage assets.”