A well-known Cork building has undergone a €5m revamp in recent years and the results will be seen on RTÉ later this month.

Belvelly Tower House, well-known for its location on the road connecting Fota Island to Great Island, is transformed thanks to new owners, Garry and Anne Wilson.

Born in Belfast, the Wilsons have lived and worked in the UK all of their adult lives, but always wanted a base in Ireland.

By 2016, they were in the market for a restoration project and they found it when they purchased the Belvelly Tower House.

Estimates vary as to when it was built by the Anglo-Norman Hodnett family, to guard the entrance to Great Island, but it is known to be more than 600 years old.

It was taken over by the De la Roch (Roche) and De Barra (Barry) families, before the Hodnetts leased back their lands.

Its last occupant was Sir Peter Courthorpe, from 1624 to 1650, and by the middle of the 19th century it was being described as a ruin.

The story of the Wilsons’ efforts is told in ‘The Great House Revival’, on Sunday, April 14.

Presenter Hugh Wallace follows their challenging and costly restoration project.

When the Wilsons bought Belvelly, it was a ruin with ivy-covered walls — it even had a tree growing out of the top of the tower.

It was considered to be at the point of no return when Garry and Anne invested their savings in bringing it back to life.

“We both grew up in Belfast in the ’70s and ’80s. Belfast was a dark place back in those times. There weren’t the opportunities for our generation, so we had to move over to England, but we want to keep a connection to Ireland,” Garry says.

“We are not very far away. We have still got lots of family who live here, and this will give us a base back on the island.”

The programme documents the team of stonemasons and engineers, as they deal with the rain-soaked Tower House.

The biggest challenge is to halt the rot, keep water out, and seal it from the elements.

The team work incredibly hard to stabilise the walls and fix the cracks that threaten to take the entire tower down.

Tower Houses are notoriously difficult to restore.

Wallace, an interior designer and judge in the recently-ended ‘Home Of The Year’ TV show, said: “I have to admire Garry and Ann for taking on such an unknown entity. There is no way of accurately budgeting for a project like this, because you will be hit, time after time, with surprises.

“They have chosen to save a national monument, but at what personal cost, and will they feel it was worth it, in the end?”

With the help of Garry’s uncle and lead engineer, John Montgomery, and his team, the couple attempt to secure the crumbling walls and seal and heat the tower.

Designer and architect Peter Plaskitt is tasked with creating a contemporary and comfortable home in this dark, cold place.

It was an epic undertaking, but, as our pictures show, the result is a home like no other.