Fallingwater was Frank Lloyd Wright’s most iconic home. Renovations will require more than a trip to Home Depot.

When America’s most famous architect built one of the world’s most iconic homes atop a waterfall in Western Pennsylvania, he didn’t leave behind a repair manual.

Frank Lloyd Wright’s 1936 masterpiece, Fallingwater, is a work of art after all, more sculpture than summer house, and it’s brought 6.3 million visitors to rural Fayette County, including Brad Pitt, Angelina Jolie, and Tom Hanks, since it opened for tours in 1964. The work was deemed the “best all-time work of American architecture” in a poll of members of the American Institute of Architects.

A home built atop a stream, that cascades down a mountainside, deep in the woods, at high elevation is bound to need some complicated TLC, though, and when that time arrives, custodians can’t just run to Home Depot.

“Frank Lloyd Wright was pushing all conventional notions of building and living and stretching materials and technologies to their limits when Fallingwater was designed in the 1930s. It stretches every notion of what a house could be,” said Justin Gunther, Fallingwater’s director. “Almost 90 years later, that creates some preservation challenges.

On a recent, sunny Monday morning, the home was still impressive, even under a massive cocoon of scaffolding, wood framing, and plastic sheeting meant to keep construction workers warm in winter. The ubiquitous sounds of Fallingwater — the waterfalls of Bear Run — was accompanied by the sounds of generators and the beeping alarms of construction vehicles driving in reverse.

Fallingwater, a UNESCO World Heritage Site, never underwent a “makeover” but restoration and preservation initiatives are constant and, ideally, seamless with the original design. In 2019, Gunther said Fallingwater began fundraising for repairs to stone walls, flat roofs, flagstone terraces, steel window and door frames, and concrete. Many of those terraces are roofs for other levels of the house, Gunther said, so vigilance against water is ever-present.

“Part of being listed on the UNESCO World Heritage list is that you’re held accountable to preserve at the highest standards,” Gunther said. “If you don’t, then you’re in danger of being removed from that list and losing that designation.”

The price tag for the multiyear project, Gunther said, is $7 million, a number that grew substantially after the COVID-19 pandemic.

“Considering the level of work being done, it’s reasonable,” he said.

While many contractors are from the Pittsburgh area, others came in from Maryland and New York. Nick Rothmeyer, owner of Allegheny Roofing & Sheet Metal Co Inc in Pittsburgh, said it’s both “exciting and challenging” to work on Wright’s most recognizable home.

“He was definitely ahead of this time,” Rothmeyer said. “There’s sections of this house that are cantilevered so far out, it wouldn’t seem possible. They’re actually part of a hillside. Nothing in this house was pre-manufcatured in a factory.”

Rothmeyer said original lumber from Wright’s era was replaced with pressure-treated wood and his work would advance on that.

“We’ll use marine-grade wood,” he said.

The restoration will also include some newer technologies — liquid grout injection — that will be unseen to visitors. That grout will be injected into the walls, Gunther said, to fill up all the empty spaces between stones and, ideally, keep water out.

“One way, water finds its way through those voids, down into the walls and into the house,” he said.

The Kauffman family, which operated a successful department store Pittsburgh, owned the land in Fayette County and used it as a summer getaway for family and employees. The waterfalls of Bear Run were a favorite vantage point for the Kauffmans and when they commissioned Wright to build a summer home on the property, they imagined scenic views of the falling stream, not being a part of it.

“They did give Wright free rein, though, and he convinced them to trust his vision,” Clinton Piper, Fallingwater’s director of special projects, said at the site.

In an era when most new homes cost less than $5,000, Fallingwater’s final tally cost the Kauffmans a little over $150,000, which would equate to millions in today’s market. Gunther doubts it could be built today.

“They were using local farmers that they trained on the job, and you just wouldn’t be able to do that and, plus, you’d probably never get the building permits anyway,” he said.

Fallingwater embraces the preservation as part of the experience, updating its blog frequently.

“The scaffolding, which took nearly three weeks to complete, creates a safe, level area for the preservation crews to waterproof and reroof much of the Main House,” the team wrote in December.

Gunther said most of the restoration work at Fallingwater is done in the winter, and the scaffolding will remain for a few more weeks while the last seasonal work continues. That doesn’t mean you shouldn’t visit.

“We’re calling them preservation-in-action tours,” Gunther said. “People will get to the house will have full access, but you know, there’ll still be some work going on, and it’ll be a great opportunity for our visitors to see preservation and progress and learn about what it takes to preserve a building like falling water. It’s a unique opportunity.”