As a kid, Tim O’Brien used to buy candy at the old-time General Store in the hamlet of Marine on St. Croix, where his parents had a seasonal vacation home about half a mile from town.

“On a hot summer day, we walked to town and pumped water from an old horse trough along the road. It’s still there,” he said.

Today, O’Brien and his wife, Francine, own 100 acres of farmland that has been in the O’Brien family for 60 years. They lease much of the land to farmers who grow alfalfa, corn and other crops.

The couple travel from their year-round home in Minneapolis to their own summer vacation home on the property. There they shop at the same General Store, and lunch at a cafe in the quaint St. Croix River town, which resembles a New England village.

“Marine has the feeling of a little town that time forgot,” said Tim. “It’s changed very little since I was a boy.”

The couple were planning to spend more time at their rustic farmhouse-style vacation home after retirement, so they started to tackle the endless home-improvement projects.

At the top of the list was deciding the fate of a 1980s-era ramshackle garage adjacent to the house.

“It was a mess, and the foundation was no good,” said architect David O’Brien Wagner, the couple’s brother-in-law, of SALA Architects. Wagner had worked with Francine and Tim on previous Twin Cities home remodelings. “They were better off starting over,” he said.

Starting over meant they could custom-design a multifunctional structure that would maximize the wooded landscape with its spring-fed pond.

The O’Briens ticked off their requests: guest quarters for visitors, including their three adult daughters; a study and musical composition space for Tim; a reading nook; and, finally, a two-car garage with a workshop and lots of storage.

They agreed that the building’s style would evoke a country barn, as a nod to the vast farmland surrounding the site.

Tim proposed the classic barn-style gambrel roof because it’s “part of the 19th-century heritage of the area,” he said.

However, Wagner’s final design is a modern interpretation of traditional barn architecture, sans the gambrel roof. A gambrel would overwhelm the main house — not complement it, said Wagner. “The design is a clean take on the time-tested barn form.”

The low-slung structure is nestled into a hill to “give it a sense of being dug in and connecting to the earth,” he said. Dual “side wings” span out from a steep-pitched gable to hold the main-level workshop and open carport. Lastly, Wagner popped out two shed dormers for additional space and to draw light into the upstairs loft.

“It’s beautiful from the highway,” said Tim. “It looks like a bird taking off with its wings spread.”

Room with two views

The modern barn’s simple, authentic materials were inspired by Marine’s historic Village Hall, as well as driven by a desire for functionality and durability.

The roof is clad in hot-dipped galvanized metal that will last about 70 years and can be recycled after that. “It’s a wonderful sound on the metal when it rains,” said Tim.

The exterior siding is vertical board-and-batten cedar combined with horizontal Douglas fir. Gooseneck barn lights are suspended over a garage door inspired by an old-fashioned barn door.

The O’Briens painted the guesthouse/retreat a crisp white. “White is a nice foil to all the other colors,” said Wagner. “It makes the greens greener, and blaze-orange maple tree more vivid.”

Inside the main level is the two-car garage and big workshop for the couple’s landscaping and gardening equipment.

A staircase climbs to the second story, where Wagner created a contemporary version of a barn’s hayloft. This loft is nearly 600 square feet, filled with light, and boasts a bedroom, study, luxe bathroom — and fabulous views.

On each end, two large pentagon-shaped windows mirror each other — but deliver distinctively different vistas. The study window faces the spring-fed pond, bordered by fragrant pines. “It’s a whole new perspective watching the wild turkeys, deer and great blue heron,” said Francine.

The bedroom window offers intimate glimpses of lindens and birches growing up the steep hillside, which looks close enough to touch. “The ferns are starting to fill in,” said Francine. “It feels like you’re in the middle of nature.”

Above the staircase, they can open a bank of strategically placed awning windows to allow summer breezes to flow through the loft. “The awning windows look good from the inside and outside,” said Wagner.

Sliding barn doors appear in every other new suburban home these days, but the one opening to the O’Briens’ bright, roomy bathroom makes sense, given the barn-inspired aesthetic of the guesthouse and its surrounding acreage. Douglas fir cabinets are topped with Cambria countertops, and the subway-tiled shower is “much nicer than the one in the house,” said Francine.

The loft feels open and airy, thanks to the two massive white-painted steel beams that support the roof, and “create a column-free space,” said Wagner.

In place of a dilapidated garage, the O’Briens now have a multipurpose “modern barn.”

It’s such an appealing getaway that the couple have been regularly sleeping there — rather than in the main vacation home. “It’s nicer than the bedroom in the house,” said Francine. “We love it in the morning with the sun streaming in.”

“I can’t wait to get here on weekends,” added Tim.