A renowned Charles Rennie Mackintosh property is "dissolving like an aspirin in a glass of water".

Since The Hill House in Helensburgh was built, the designer's 1904 domestic masterpiece has been absorbing the rain, putting the building and its unique interiors at risk.

Thermographic imaging previously revealed the severity of the water damage.

To protect the much-loved property, the National Trust for Scotland has embarked on a pioneering conservation programme.

The trust's president, historian and conservationist Neil Oliver, hopes the construction of The Hill House Box will stop the building from "dissolving like an aspirin in a glass of water".

Designed by architects Carmody Groarke, the steel frame - covered in a chainmail mesh designed to protect the house from rain - will allow the walls to dry after years of disintegration.

The semi-permanent enclosure will also prevent more damage and allow further conservation work to take place.

Oliver said: "Once under cover, the building can dry out under controlled conditions and the trust's experts will begin the process of finding the long-term solution that will save this iconic structure forever."

As well as protecting the property from the weather, the box will give visitors the chance to get a new perspective on The Hill House from elevated walkways looping around the building.

A gradual opening to the public will take place on Saturday, with a full opening set for June 7.