"We asked ourselves if we would still be interested if the house were to fall down," says Elizabeth; "The answer was 'yes'."
Not that they advocated such a catastrophe. But with a "dangerous buildings order" in place (the 18th-century house was riddled with wet and dry rot) and had a huge tree growing out of the chimney, they had to be realistic.
Unable to set foot inside, the couple were nevertheless beguiled, not just by the property's faade (boasting crow-stepped gables and pepper-pot turrets) but also by the romantic setting.
Close to the Ross-shire village of Evanton, Assynt House sits in six acres of woodland, surrounded by farmland, yet it's just a 30-minute drive north of Inverness. Once the dower house for a local estate, the property played host to President Franklin D Roosevelt and his wife Eleanor during their honeymoon.
Although they had no experience of major renovations, Elizabeth and Graham were looking for a project to get their teeth into. They were living in Essex when they began looking at properties both in the south, and in Ross-shire, where Graham grew up, and where his family still lives.
Nothing captured their imagination like this place, although they knew it was a building that would have to earn its keep. Soon after they bought it, the couple contacted an architect and building contractors recommended by Graham's family.
Emergency repairs were carried out, not least to cover a gaping hole in the roof. The house had been uninhabited for eight months, but prior to that was home to an elderly lady.
"Fortunately she moved out just before the roof fell in to her bathroom," says Elizabeth.
Ultimately, the entire roof was replaced, reusing original slates. Sadly, such an exercise in salvage wasn't feasible throughout the house, partly due to decay, but also because it had fallen victim to looters while empty, so little details such as doorknobs were lost.
However, there were some clues left. Mouldings were taken of original cornices (too softened by rot to be saved) so replicas could be reinstated. The extent of rot meant the whole place had to be taken back to the bare stone walls.
"It got worse before it got better," says Graham.
All the floors were replaced, as were windows (in original style) while the entire building was replumbed and rewired. In the drawing room, timber wall panelling was removed and treated before being replaced, although some sections were too mouldy to be salvaged.
"We used timber from the grounds, milled onsite and fitted by local joiner Michael Gunn," says Elizabeth, explaining that Michael later got married in this room, in which he had invested such painstaking work.
Few changes were made to the floor plan; one large bathroom on the first floor was divided to create two en suites, and a large cupboard at lower ground level was converted for the same purpose. All seven generously sized bedrooms now have en suite facilities.
During the initial work the couple (working out a year's notice in their jobs) travelled to Scotland regularly from Essex and by August 2003 had made the move north.
It was always their plan to utilise Assynt House as a luxurious holiday let, and a venue for celebrations including small weddings.
"Sharing the house enabled us to keep it once the renovations were complete," says Elizabeth.
After their move it was another few years before the couple welcomed their first guests (for New Year 2006). As well as outstanding jobs, such as replacing a section of the staircase and fitting new bathrooms and a kitchen, the scale of the house meant it took time to decorate and furnish.
"We'd go to Edinburgh's auctions and fill up a van," says Graham; "But back at the house the van contents never seemed to fill the rooms."
The couple shopped for predominantly period furniture, but the mood never becomes overly weighty, and bedrooms on the lower ground level (which boast underfloor heating) have a sharper, contemporary style. Elizabeth was determined to salvage the few items she could, such as a corner wardrobe now located in the "pink" bedroom, and a cast iron roll-top bath into which a steel beam had crashed prior to the renovations. It's been satisfyingly spruced up with warm red paint.
Although most bedrooms had fireplaces, many were filled in to strengthen the building, but three splendid open fires survive in the public rooms.
"We replaced damaged surrounds with originals from the bedrooms," says Elizabeth, while new grates were instated in period style. Two servants bells sourced to fill holes beside the drawing room fireplace fit so well Elizabeth believes she may have stumbled upon the originals.
The emphasis throughout Assynt House is on home-from-home comfort.
"We really wanted this house to feel special, so it was important to equip it with the luxuries as well as the essentials," says Elizabeth.
Although Assynt House is let on a self-catering basis, guests find many comforts akin to a hotel stay. There's daily housekeeping and Graham, who retrained as a chef since moving back to Scotland, provides an optional catering service, whipping up anything from a simple stew to lavish dinners. The couple are modest about his talents, but a look at independent reviews reveals his cooking to be something special.
Maintenance of such a building is ongoing. Graham is hands-on with this, and upkeep of the fantastic gardens. Today the couple and two-year-old Charlotte live in a cottage in the grounds, from which they ensure guests' satisfaction in an unobtrusive way.
From weddings to fishing, gorge walking to golf, visitors find themselves at Assynt House for many reasons, but need no excuse to come back.
Tel: 01349 832923, www.assynthouse.com
This article was first published in The Scotsman, 1 January, 2011