BAINBRIDGE ISLAND, Wash. — At a frequency heard only by the most zealous do-it-yourselfers, a down-on-its-luck fixer-upper on Bainbridge Island sent out an insistent SOS, crossing county lines, one formidable body of water and more than 70 years.

Other potential rescuers steered clear, but Mark and Wendy Johnson ran right toward the trouble. They had just achieved that magical, elusive state of completion in their home in Redmond, after all — so, clearly, it was time to move.

The please-help-me home, basically a cabin back in 1920, when it was built, had been significantly remodeled in 1976. “The place needed a lot of love, and more space,” Mark says. “I smiled at Wendy and said, ‘I’ve got projects again.’”

Understatement alert. The Johnsons bought that home in 1993, so there’s been more than two decades’ worth of projects — so far.

“We tore down a lot,” says Mark, who has a degree in architecture but never practiced (he’s worked in construction and, for the past 20 years, in real estate for The Benaroya Company; Wendy works for Seattle City Light). “I knew commercial construction, but residential is different.”

Live and learn, you know. Live and learn.

“The first thing we did was build a pier,” he says; it’s 128 feet long, of reclaimed piling and framing material, with a floating dock. (The Johnsons live on a gorgeously secluded ¾-acre lot with 75 feet along Eagle Harbor.) “I did that dock for $15,000, did it mostly myself. I did my whole dock and pier for less than what just the permitting would cost today.”

In 2001, after years of “noodling concepts” and accumulating “the money and guts to pull the trigger,” Mark designed a complete remodel of the house, which included demolishing 65 percent of it. “I added 1,000 square feet but tore out 1,000 and added on to the second floor,” he says. “I drew up the plans, got the permit and named a general contractor (the late Bob McAllister, of The Sensitive Carpenters) who did the concrete and framing.”

In 2009, Mark designed and built a garage, “doing 90 percent of the work myself.”

In the backyard, he built a retaining wall and a deck, created a firepit and laid lots of pavers. In the front, he built a working drawbridge at the entry (“Go away!” it jokes, we think, when drawn) and another bridge midway.

This sounds like a lot of structural (hard!) work, and it is, but it’s also beautifully detailed, admirably sustainable and amazingly creative.

In the living room, screens from the original river-rock fireplace rest in windows looking toward the water. (Mark made the fireplace’s new mantel and vertical supports from a single 600-pound slab of fir — “one of my favorite things I’ve done.”) Treads for the flared staircase he built are from an on-site fir tree. Salvaged material from the old garage became a new “outhouse”-themed tool shed, and a new SS Minnow boat shed. Reclaimed bleacher seats turned into shelves in the office. Light fixtures in the hallway, dining room and laundry originated in the old Broadview Elementary School. And a hotel phone booth serves as a clever trapdoor landing atop stairs to the basement.

“I don’t use reclaimed material so much for environmental reasons as for reasons of aesthetics, creative reuse and hopefully costs,” Mark says.

Throughout the house, Mark’s collections — phones from the 1940s, car phones and cellphones from the 1980s on up, unusual album covers, “politically incorrect” shot glasses — find places of honor, as do his newest creative projects.

After all that home work, Mark says, “My body wore out, and I switched to art pieces. Outside art and inside art.”

He painted their first dog, Topper, and their current dog, Chevy, on the living-room rug (which used to be the dining-room rug). He created the “industrial” aluminum ball on the mantel and “Maxine Vaccine” in the front room (Barbie dolls from Goodwill dangle from a milking machine from his family’s farm), and fashioned a working doorbell out of a wineglass, two beer bottles and a wine bottle. There are dozens more (maybe more).

“My wife has been a good sport about the whimsical nature of the improvements I’ve designed and built over the last 23 years,” Mark says. “You can tell I didn’t stay in architecture. It’s a funky house.”

Adds good-sport Wendy: “I feel like we’re blessed to be here, and we’re caretakers. We bought the house, and it was almost a teardown. We could never have afforded this, or afford it now. What I love about the way we live: The site is so special, the house needs to be really welcoming and warm and easy. We never have people take their shoes off. I love this house and this place. I think it’s a wonderful house. He’s a busy boy.”