The scheme hopes to safeguard the future of the Torwoodlee Tower near Galashiels which dates back to 1601.
A fundraising campaign was launched in 2001 to generate the resources necessary to consolidate the building.
A two-year £150,000 project is now able to get under way which should help to make the structure safe to view.
The tower plays a part in the history of Galashiels and its annual Braw Lads' Gathering celebrations.
James Pringle, the 14th and current laird of Torwoodlee, said: "In 2001 we launched a campaign to raise the funds we needed to consolidate this romantic ruin.
"That year was the quincentenary of 1501 when we first came to Torwoodlee and it seemed a very apt moment to be thinking of the next 500 years.
"Now, thanks to the generosity of the Fallago Environment Fund, Historic Scotland, local people and Pringles around the world, we are in a position to undertake the two year project to stop the tower falling down any more."
He said when the project was finished the tower would be "safe for people to look at and admire once again".
A project has started to try to stabilise a historic Scottish Borders tower which has fallen into an "increasingly precarious" condition.