The Daniel Thwaites-owned hotel, which overlooks Lake Windermere on a six-acre site, will close in April ahead of an extensive refurbishment which will cost between £6m and £15m and could take up to 18 months.
Works on the grade two-listed main house, which was built in 1895, will involve the refurbishment of existing bedrooms, including making one accessible, as well as restoring original features such as the inglenook to the fireplace within the existing piano room.
Various external alterations to the main house include the removal of a Victorian-style conservatory which will be replaced with new glass and bronze clad structure.
The addition of a three-storey, 13-bedroom block is also proposed and will be situated between the main house and the Lakehouse, which will benefit from an additional two bedrooms.
A roof extension to the boathouse, which contains one private bedroom, will provide a larger en-suite bathroom.
A proposed spa would see the alteration and of two existing buildings known as the Carriage House and Staff Block. The Spa contains a new swimming pool at ground floor level and part external hydro pool. At the same level the pool area links with the existing staff block which is reconfigured to provide further guest bedrooms, treatment rooms alongside retained staff bedrooms.
A jetty, for which a planning application was submitted in July last year, and a tearoom form part of the project.
The project team includes Campbell Driver Architects, Rural Solutions on Landscaping and Goff Associates which is designing the interiors. A main contractor is yet to be appointed.
Brewery and hotel operator Thwaites acquired the from Thomas Noblett in August 2017.