Planning permission is before Highland Council for the first stages of the Inverness Castle transformation.
Highland Council took possession of the keys to the castle on March 27, when the court service moved to the city’s new justice centre.
The hope is to get the statutory planning underway for the change of use of the castle from courthouse to visitor attraction by June, although work on site will not be able to start until lock-down is lifted.
Architects LDN want to demolish a cell block and make various internal alterations to enable investigations and surveys of the building fabric.
They have defined the areas which they need to change in order to carry out condition surveys and check for potential problems like asbestos or rot.
Pre-pandemic intentions to hold an open-doors weekend at the castle in May to let the public see the castle before it closes for its dramatic transformation were shelved in March.
A preliminary ecological assessment planned for this period is also on hold, as are plans to put hoardings depicting historical scenes around the castle during the work.
The transformation of Inverness Castle is a Highland Council project, managed by High Life Highland on behalf of The Highland Council.
The project includes new galleries to bring national and international exhibitions to the Highlands, new museum displays celebrating the culture and heritage of the Highlands and a revamped castle esplanade and grounds.
A High Life Highland spokeswoman said: “Nothing will happen physically on the site while the lockdown is in place and, where possible, we are continuing to work on processes that can be undertaken safely by people working at home.”
Inverness provost Helen Carmichael said:“The preparation work will help the team establish what’s behind the walls and down in the dungeons.
“It’s more essential than ever that the project gets underway as soon as possible in order to be able to rebuild our tourism sector after the crisis and be ready to welcome our visitors in future.”
The transformation, planned over three phases and expected to take three years, includes reinstating the original front door of the South Tower as the formal entrance to the castle, and introducing a single-storey infill in the courtyard between the South and North Towers, linking the buildings for the first time in history.
The original court room will be protected and universal access throughout will be improved.
Rural Economy and Tourism Secretary Fergus Ewing, who co-chairs the Inverness Castle Delivery Group, said: “We want to see a new life for the castle that builds on its existing attraction, offering visitors and locals alike a quality offering that encourages tourists to both visit and stay longer in the area.”