It is said that we don’t appreciate what we’ve got until it’s gone, but in the case of downsizers Fraser and Lynn McCathie, that isn’t strictly true.

The McCathies have lived at Lynton, the B-listed Arts and Crafts-style masterpiece built by the architect William Leiper in Helensburgh, since 1986 and have come to love the place so much that once they sell up they are moving to another Leiper house in the town — albeit on a smaller scale befitting their status as empty-nesters.

Lynton sits to the front of Charles Rennie Mackintosh’s revered Hill House, providing a wonderfully apposite visual metaphor. Leiper’s masterpiece, built in 1908, is both literally and figuratively in the shadow of the house that Mackintosh designed for the Blackie publishing family, which now enjoys life as a tourist attraction. But for some connoisseurs, such as Peter Gillespie of Savills, Lynton is just as significant a house, hidden away from the prying eyes of the oblivious Japanese daytrippers by gleaming gates, statuesque trees and private walled gardens.

Gillespie says: “South of the border, many well-heeled buyers aspire to owning a house by [Edwin] Lutyens, and William Leiper is his star equivalent in Scotland. He is an architect who stands comparison with all the great domestic architects of the last 100 years.”

But Leiper’s status was unknown to the youthful McCathies when they bought Lynton in the less enlightened 1980s.

Lynn says: “It was a different time then and period homes, especially period homes of this quality, were viewed less as assets and more as money pits. We have a local carpenter to thank for saving the butler’s pantry and showing us exactly what we had under our noses.”

Fraser continues: “We’d had slick kitchen salesmen here wanting to rip everything out, but this local craftsman led us down the road of becoming custodians for a house that has rewarded us with so many happy memories in return for the care we have lavished upon it with each passing year.”

The six-bedroom house, which also contains spacious office facilities in the attic and “granny flat”-style accommodation on the upper floor, remains largely unaltered in terms of original features, with sandstone chimneypieces, inglenook fireplaces and leaded windows with exposed stone mullions. The Kauri pine-panelled doors betray the classic Arts and Crafts touch of being fixed with wooden pegs rather than nails.

Another Leiper signature is that the house is entered via the south-facing rear elevation, ensuring that the public rooms are bathed in summer sun. The house also maintains its original grounds, and the fact that no views have been compromised by additional nearby building ensures that Lynton is a rarity, not just in Helensburgh but in the whole of central Scotland.

Renowned as an architect of “art” villas within Glasgow, Leiper is also known as the creator of the gothic Dowanhill Church, the banqueting hall of Glasgow’s City Chambers, the magnificent Templeton carpet factory and the exuberant Sun Life building on West George Street. Celebrated for his signature use of polychrome brick, ceramics and mosaic as external decoration, Leiper even found time to design Livadia, the Russian imperial yacht.

Lynton, however, is Leiper’s crowning achievement, a restrained synthesis of his life’s work that is practical, beautifully conceived, grand and yet intimate in scale. Lynton is imbued with the kind of expressive flourishes and hidden attention to detail that only reveal themselves over time.

In the era of mass production, Leiper’s Kauri wainscot panelling, pitch-pine floors and handcrafted brasswork would be nigh on impossible to replicate today.

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