Work is to start this month on a new Stables restaurant at Belton House.
South Kesteven District Council has approved the £3.2 million scheme, which will take around a year to complete.
Project manager Emma Lockwood said the National Trust is excited to be moving forward with “essential conservation work that will rehabilitate the stables building.”
The Stables are only one of 21 Grade 1 listed stables in the country, making them extemely significant, but over the past 40 years their upper floors have fallen into decline.
Emma explained: “We have been working closely with the local planning office and Historic England to find the right approach for this unique building. Work will begin in late February to preserve the existing features and reinstate those that have long since been lost.
“Over the next 12 months, specialist conservation builders will work alongside skilled craftsmen to repair lime plaster, conserve the historic stabling and enable a sustainable use to secure the future of this special building.”
Plans include extending the ground-floor restaurant by adding a dog-friendly cafe. There will be education space, offices, meeting rooms and welfare facilities for staff and volunteers on the upper two floors. As a Grade 1-listed structure, the outside appearance of the building will not change.
The National Trust says the £3.2 million cost will be funded by money raised at Belton House through membership sales, day admissions, retail and in the cafes.
While the work is underway and the restaurant is closed, Belton House plans to have a temporary catering pavilion erected nearby to help maintain services, but the application for this has yet to be approved.
Emma added: “It is thanks to our supporters visiting and enjoying Belton, that enables us to save this special building. This project is absolutely what the National Trust is about, preserving historic places and providing greater access for our supporters.”
South Kesteven District Council’s decision notice commented: “The proposed alterations will bring the currently unused and under-used parts of the building into use. Although the works will result in less than substantial harm it is considered that the harm is outweighed by the public benefit.
“Furthermore, the proposed uses are considered to conform with the existing use of the site whilst not impacting adversely on residential amenity, protected species or highway safety.”