Wimbledon champion took over running of hotel with wife Kim in December
It was run by a management firm until December when Sir Andy, 36, and wife Kim announced they would be taking over the running of it. A planning application has been submitted to Stirling Council for permission to transform a disused building in woodland surrounding the hotel into a 'wellness cottage'.
Plans show the building will incorporate a reception area, a treatment room and shower facilities.
Documents accompanying the application state: 'The current planning approval has been reviewed with the decision to take forward the existing estate property as a Wellness Cottage.
'The intention is to repurpose the vacant property to provide a range of therapy treatments for visitors and guests within the woodland setting of Cromlix.
'The property will be given a range of external improvements including new replacement windows, roof and render repairs.
'The internal spaces will be fully designed to provide a reception and treatment room. All aligned to the Cromlix Vision as exemplified with the recent hotel internal refurbishment.'
The local authority is due to make a decision on the application by next month.
Last month Murray won a battle with wildlife campaigners over plans to build luxury woodland cabins in the grounds of the hotel.
A planning application has been submitted to Stirling Council for permission to transform a disused building in woodland surrounding the hotel into a 'wellness cottage'
Plans show the building will incorporate a reception area, a treatment room and shower facilities. The local authority is due to make a decision on the application by next month
Sir Andy's plush five-star hotel has won a string of hospitality industry awards. Its website describes the 'luxurious rooms' as 'tranquil, restorative places that aspire to bring a little of the outside, in'
Cromlix reopened in March following a three-month refurbishment programme overseen by Kim Murray. As well as billiards, the hotel offers falconry and shooting, and of course tennis
The tennis star held his wedding reception at the hotel in April 2015, and elder brother Jamie was married there
He submitted proposals to erect nine chalets of varying sizes to accommodate more guests.
However, the Scottish Wildlife Trust opposed the planning application over concerns of the impact it will have on breeding birds and frogs and toads.
Cromlix reopened in March following a refurbishment programme overseen by Kim Murray.
She said at the time: 'It feels like the right time to look to the future, and what we can achieve over the next 10 years and beyond.
'The hotel has closed for a three-month refurbishment which is the first stage in a series of planned works to breathe fresh life into both the building and business.
'This is very much a family affair and I am delighted to be getting involved in overseeing this makeover (selecting wallpapers, toiletries, logos and everything in between!) so that Cromlix becomes more reflective of our personal tastes and attitudes.'
The tennis star held his wedding reception at the hotel in April 2015 after getting wed to Kim, 35, at Dunblane cathedral and elder brother Jamie was married there.
