Not every house built on a cliff has stayed on a cliff. So how do homeowners and architects take on this challenge — one that is rewarded with glorious, unobstructed ocean vistas, but also full of potential problems — and still sleep well?

Building a home attached to a sheer wall of rock means balancing aesthetic temptations with the realities of exposure, accessibility, zoning issues and design. Jaime Bartolomé Yllera, co-founder of GilBartolome Architects, says that the danger is part of the draw.

“It’s in some sense dangerous, but you can safely experience it,” he said. “Engineering goes a long way.”

His firm won the bid to build the House on the Cliff in Salobreña, on Spain’s Costa Tropical, with a design that Bartolomé calls a “cave model,” cut like a triangular bite into the side of an incline, in this case at a 42-degree grade.

Bartolomé fabricated micropiles that dig 60 feet deep into the ground and drilled anchors horizontally 60 feet into the rock.

“For that house to fall into the sea, the whole mountain would have to go into the sea,” he said.

The construction crew started by excavating earth to make a vertical retaining wall. Whereas houses on level land are built from the foundation up, houses in the cave model are built from the retaining wall downward: Other floors are added below it, like building a set of stairs from the second floor down.

Though houses built this way can incur additional construction costs, Bartolomé said they were able to build the 2,400-square-foot House on the Cliff for about $200 per square foot, including the retaining wall and the bespoke furniture, for a total construction cost around $480,000.

To take on this challenge as a homeowner, Bartolomé said, “you have to have energy. You get all sorts of challenges, so to be worth it for the client, someone really has to have the vision.”

The owners of the home, Sandra and Jaime Vecino, had a vision from the first time they saw the property, riding past it on his father’s boat. They were living in Madrid, but Vecino had always summered with his family in the area, hoping he’d find a place there to build a house of his own.

While her husband pointed toward the property, Sandra Vecino asked, “How would you build a house there?” — a question that was echoed by the rest of the family. They found out the answer after they purchased the land, considered four designs and chose the most unusual one, from GilBartolome Architects.

“I wasn’t sure, of course. When we saw that house I said, ‘My God, this is not going to fall, really?’ ” she said. “I was scared.”

They began to build in 2012, before they had children, and for four years spent summers and offseason weekends there. Their full-time house is just five minutes from the beach, but she says it’s not the same as life on the cliff.

“It’s as if you’re far away from everything, in a bubble, in your own world,” she said. “It’s magic. It’s like the sea is just for you because it’s not just a bit of it, it’s an immensity. The sky as well. It’s everything.”

They enjoyed the isolation when they wanted to have loud parties. After having three young children, though, the family decided to use the very non-childproof house just for weekends and rent it as a vacation home for about $600 a night in the summer and about $350 in winter, so others can experience it.

The House on the Cliff is striking, but it has competition. Laertis-Antonios Ando Vassiliou, principal architect and director of LAAV Architects, who grew up with a view of the sea in Greece, creates designs for even more daring projects to fit the kind of clientele who might like to live on the edge.

“I think you need to be a little bit of a daredevil,” he said.

Potential buyers have tracked him down for his designs, such as the Casa Brutale concept, renderings of which went viral in 2015 — and for good reason: it’s a home that doesn’t sit on a cliff but in it, like a drawer in a dresser, with a pool for a ceiling and glass windows flush with the rock face.

Alex Demirdjian, CEO of Demco Properties in Lebanon, wanted to make the house a reality in Beirut. When Vassiliou partnered with Arup Group to lead the engineering, he found himself in a meeting with structural and mechanical engineers, where he asked, “Is this possible? Is it feasible?”

“Well, what’s the budget?” asked one of the engineers. “If there is a budget, everything is possible.”

The budget in 2016 was equivalent to about $3.25 million today. Cliff homes present obvious challenges that can be costly to overcome. “They have erosion, they have landslides, so they are tricky,” said Vassiliou. “But of course, from the standpoint of science and engineering, there are many solutions.”

Even someone with the budget for it has to find the perfect location, a quest that has taken Vassiliou around the world. Geotechnical tests, which extract a core sample from the rock, have shown several spots to be untenable.

“The best rocks are the ones that are pure stone,” said Vassiliou, adding that the most stable is igneous rock, such as granite or basalt.

And it matters just as much what’s above the location as it does what’s below it. In Lebanon, Vassiliou initially found what seemed like a great cliff, but more cliffs rose above it, presenting the risk of tumbling stones.

Because of these difficulties, broader sociopolitical issues and the pandemic, the project remains to be realized.

Cliff houses don’t always have to be such grand affairs. Marialena Hatzigeorgiou and her husband, Daniel Braig, who live in Virginia, just finished their first summer in their new cliff house, one of two simple houses they planned for the future of their two sons, each about 800 square feet and costing about $200 to $300 per square foot to build. They built on the Greek island of Skopelos, on property that had been in her family for decades, but used to be home only to grapes, olive trees and hens.

“They’re not really big houses, but they’re just perfect,” Hatzigeorgiou said. “The view is just breathtaking. It would make you stop doing whatever you’re doing to just sit there and look at the water.”

They still met challenges. To get permission to pave an access road, they had to go to court and show World War II-era photos of a mule path that proved the area had been used for entrance even back then. When they built the house in 2018, they chose to forgo testing the cliff, because the family had owned the property for so long and not seen any shifting, even after pouring a foundation and basement back in 2012.

“There is a house just a couple of corners around us, and we feel that if it’s doing well, we are doing OK,” Hatzigeorgiou said, adding that they routed rainwater with erosion in mind, would insure the house soon and will get it tested if they see any changes.

“For the time being, I’m not really worried about it.”