Aimee Gardner and Dave Linnard were standing in the basement of their newly purchased, 1869 Hudson Valley fixer-upper when they heard a strange tinkling — like tiny drops of rain. They would soon learn this is the sound a lime mortar stone wall makes as its particles shift — right before it collapses.

Seconds later, the entire north wall dropped vertically, some half a foot, with a thundering whoosh and an eruption of dust, leaving the floor above them precariously cantilevered. “We’re just lucky it didn’t fall sideways,” Ms. Gardner said. It became another thing to add to the punch list as they restore their first home, a project that’s taken, so far, eight and a half years.

Ms. Gardner, 55, an arts administrator at a local nonprofit, and Mr. Linnard, 65, a software engineer with a knack for design, call it “Disaster Mansion.”

In December 2017, they bid on the once-grand house in Kingston’s tiny Ponckhockie neighborhood in a city tax auction, for $53,500. Their offer narrowly beat a local landlord and, as they recall, a “French tourist” who seemed to have bid accidentally.

“All the contractors just stopped bidding at about $35,000,” Ms. Gardner said. But the couple, who had been renters in the Bay Area until their cross-country move for Ms. Gardner’s new job, felt optimistic about what they could see through the mostly boarded-up windows.

Originally built by a wealthy Irish carpenter, David Gill, the 3,200-square-foot showy Italianate had been abandoned for years when they closed that January, long stripped of its fixtures, copper, plaster and lath, with crowbar marks on the doors from break-ins past.

Still, it ticked their boxes. “There were plenty of houses we could have afforded, but we wanted something with character,” Mr. Linnard said.

After the Augean task of clearing away the previous owner’s belongings, including moldering books, old credit cards and vintage sex toys, and patching the roof so ice would stop forming inside, the couple got to work salvaging, stabilizing and restoring. They sought advice from historic preservation experts while spending “thousands of hours” nearly every evening and weekend on the house.

They live in a $1,600-a-month one-bedroom rental nearby, a line item that has added more than $160,000 to their project budget.

One of the earliest projects was the yard, where they removed mounds of trash, scrap and overgrowth, then leveled a steep drop-off into a gently sloping lawn with fruit trees, dogwoods, a Snowball viburnum, ferns and wildflowers.

They stabilized the foundation and reinforced structural beams. They removed a collapsing back deck, a rotted stairwell and a superfluous, free-standing concrete wall along the back of the house that blocked light to the ground level.

Then, they got to work converting a damp, dirt-floor cellar into a one-bedroom apartment, digging down to allow for higher ceilings and pouring new floors. Wiring and plumbing throughout the house is being completely overhauled. Original trim has been removed so it can be restored. The doors are being refurbished, the interior staircase is being rebuilt and the windows all need to be replaced. The entire house, as of now, is down to the studs.

As they’ve chipped away at these jobs over time, they’ve earned the community’s trust. “They probably thought we were rich when we came,” Ms. Gardner said of the neighbors. “People were walking by like, ‘Are you going to turn this into an art gallery? Are you going to flip it?’ I’m like, ‘No, we just want to live here.’”

Some people are judgmental about the project, she added. Other passers-by exclaim, “This is gorgeous!” “When you hear comments like that from strangers, it does lift you up,” Mr. Linnard said, “because it is a challenge. There have been meltdowns.”

It’s also been a learning experience. For example, the second time, months later, that Mr. Linnard heard the tinkling sound, he knew to run for it.

As time has passed, they’ve all but eliminated their reliance on contractors, at least for the jobs they can learn to do themselves. “If we had more money, I would pay people to do stuff,” Mr. Linnard said. “And we do hire people as we go. But we’ve learned a lot, and we do a lot,” from shoring up a foundation to installing radiant heat.

And they don’t cut corners: They recently rebuilt the collapsing front porch with true-to-period, mortise and tenon joinery instead of modern metal brackets.

Mr. Linnard’s background is in math and computing, but back in Oakland he dabbled in metalwork and woodworking. Ms. Gardner is game to learn, taking woodworking courses and masonry workshops.

Today, bundles of insulation line the basement wall. Upstairs, UV lights on a pulley system are curing linseed oil paint on custom door transom panels. Sharpie marks on the wall add up to 22: the number of floor tiles they’ve molded, painted and sealed by hand after deciding the manufactured tiles they loved were too pricey. They estimate they’ll need around 700.

“Watch out for the bees,” Mr. Linnard said, swinging open the door from the cupola onto the roof. A wasp’s nest dangled from the inside like an oversized Christmas ornament. To the right is Hasbrouck Park. To the left, the Hudson beyond a stretch of industrial waterfront, once a brickmaking empire.

This cupola will host nine of the home’s 38 windows, all of which Mr. Linnard is building by hand, with advice — and donated materials — from a supporter at the Architectural Resource Center, plus a trove of antique glass acquired on Craigslist. “It’ll be lovely in winter,” Mr. Linnard said, “sitting up here, watching the snow.”

The couple spent $100,000 on the initial renovations, from a loan extended by a friend. Since then, Ms. Gardner estimated they have spent an additional $100,000 and that the total cost of the work will ultimately total close to $400,000. “I think we are saving a little by doing a lot ourselves,” Ms. Gardner added, “but we’re still paying rent at our apartment until we can move into the ground floor.”

The wait does get to her sometimes, Ms. Gardner said, sitting on an overturned five-gallon bucket in her future garden apartment. “Other days I’m like, well, I’ve got a roof over my head.” Not being in debt is some consolation.

Recently, Mr. Linnard was laid off. This gives him more time to work on the house, he said.

The couple said they hope to move in next year. “We said that last year. And we probably said that the year before,” Mr. Linnard laughed. But it’s different now, Ms. Gardner added: “The punch list is definite.”