The multi-million-pound extension will include a brand-new ballroom and 68 bedrooms, following the news of planning approval from the Loch Lomond and The Trossachs National Park Authority.
A new 7,345-square-foot ballroom and "pre-function" space will feature spectacular views of Loch Lomond.
Expected to be completed by summer 2021, the extension will feature the bedrooms on the upper three floors, the majority featuring large balconies with loch-facing views.
A large outdoor terrace on the lower ground floor will create a separate, external space for smaller events with views overlooking Loch Lomond and the hills beyond.
Cameron House Hotel is due to re-open in late 2020. The main section of the hotel was destroyed by fire in December 2017. Two holidaymakers were killed in the incident.
Andy Roger, resort director at Cameron House, said: “We warmly welcome the National Park Authority’s planning approval, which is a major step forward in the multi-million-pound redevelopment of the hotel.
“The proposed extension will maximise the stunning views of Loch Lomond whilst fully respecting the architectural integrity of the original house.
“The extension will also allow us to increase the number of weddings, functions and guests we’re able to accommodate at Cameron House, and we’re confident these improvements will have a significant positive impact on the local economy.”
Cameron House is investing £17.5 million in the extension, which has been developed by architectural firm 3DReid, closely supported by principal designer Thomson Gray, interior designer Greyline Design, and Hirst Landscape Architects.