Work is due to start in January following planning approval from the Lake District National Park Authority.
The hotel, part of Lake District Hotels, will start with a ground-floor refurbishment of the bar, lounges, reception, restaurant, lobby and function room, for completion by summer 2017.
Then the existing leisure facilities, including the outdoor pool and squash court, will be demolished to make way for a riverside brasserie-style restaurant overlooking Watendlath Beck, 18 new bedrooms and a full spa with treatment rooms, heat experiences and infinity spa pool.
The Graves family, which owns the group, says it worked with architects and interior and spa designers to give a contemporary feel to the 146-year-old property, while retaining its proud identity.
Director Charles Graves said: “It’s a natural progression and will ensure that the hotel remains synonymous with luxury and maintains its position among the leading hotels in Cumbria.”
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here