WHAT’S THE STORY?

HILL House in Helensburgh is going to need a futuristic shield around it to help save the historic A-listed building designed by Charles Rennie Mackintosh from crumbling.

Owned by the National Trust for Scotland (NTS), Hill House is recognised as the housing masterpiece of Mackintosh, Scotland’s greatest architect of the 20th century and an influential artist as well.

Perhaps only the Glasgow School of Art surpasses Hill House in importance as a building designed by Mackintosh, who, with his wife Margaret Macdonald, created almost all the jewel-like interiors and fittings of Hill House as well as the external grey roughcast walls and tiled roof.

WHO WERE THE ORIGINAL OWNERS?

AS the 19th became the 20th century, the successful publisher Walter Blackie was looking to move his family out of Glasgow, just as Helensburgh was becoming a fashionable town on the Clyde, linked to the city by train.

Blackie was introduced to Mackintosh, then a young architect with the respected Honeyman & Keppie practice, having started with them as a draughtsman in 1889. Macintosh won the Alexander Thomson Travelling Studentship the following year and his travels abroad greatly developed his thinking about form and function. He had already shown with the drawings for House for an Art Lover – built in Bellahouston Park 90 years after he designed it – and the Glasgow Herald building, now The Lighthouse, that he drew influences from European Modernism, Japan via the trend known as Japonism, and Art Nouveau, as well as the numerous forms of Scottish art and architecture, to create his own now-famous style.

In 1902, Blackie commissioned Mackintosh to design Hill House, stipulating only that it have grey roughcast or pebbledashed walls and slate roofing in line with a traditional Scottish building. It would be the roughcast – otherwise known as harling – that would give every owner since Blackie a hard time.

WHY IS IT IN SUCH POOR CONDITION?

PUT simply, the weather.

Built in the early 1900s, Hill House was designed by Mackintosh as a home first and foremost – he studied the Blackie family’s daily lives first – but also as a statement of his philosophy that functionality should come before fancy design. As it happened, Hill House was both functional on the outside and quite stunningly “fancy” on the inside, which is why it wows visitors to this day just as it did when it was finished in 1904.

The problem was that, as per Blackie’s orders, Mackintosh coated the house in grey roughcast, using the then relatively new Portland cement.

Now Helensburgh is a lovely town, but residents have an old saying: “If you can see Greenock across the Clyde, it’s going to rain, and if you can’t see Greenock, it’s raining.”

Wind and rain ripped into the roughcast over decades and frequent incursions of damp often required patching up. As the NTS says: “The Portland cement has never been a real match for the west coast weather and from the day the harling mix was applied it has let in moisture.”

WHAT IS THE SOLUTION?

A LONG and costly one, with NTS appealing for £4 million to fix Hill House once and for all. There had been a restoration after it was donated to NTS but the weather has continued to win.

The first stage will be to surround the building with a see-through protective shield, almost a “porous cage”, as NTS describes it, that still allows a degree of moisture penetration – this is essential to ensure the walls do not dry out too quickly and crumble as a result.

Once the shield is up, NTS’s experts will devise the cure. As chief executive Simon Skinner says: “Our conservation and architectural heritage teams can start work to find solutions that will respect the historic and design integrity of the building, meet the standards and obligations required by its listed status and ensure that this precious place will survive to inspire future generations.”

NTS admits the work will take years, but the end result will allow visitors to marvel at the creations of Mackintosh and his wife unhindered by the weather.

WHAT IS ALL THE FUSS ABOUT MACKINTOSH?

FIND out in The National on Tuesday when Hamish MacPherson’s Back In The Day column will profile this enigmatic genius.