Buck Holzemer lives in a blue steel box that shimmers under the setting sun. Even the inside walls are steel, he noted, knocking on a kitchen wall to prompt a tinny reverberation.

But Holzemer’s unconventional Minneapolis residence, known as a Lustron, represents much more than 1,000 square feet of living space within a metal shell.

The Lustron Corp. built only about 2,500 of these prefabricated metal houses between 1948 and 1950. “This was the first effort to mass-produce an all-steel house in the U.S.,” said architectural historian Larry Millett, author of “Minnesota Modern: Architecture and Life at Midcentury.”

The standard two-bedroom Lustron, short for luster on steel, was constructed inside and out using porcelain-enameled steel panels (the same kind used to make White Castle buildings) connected to a steel frame.

The interior cabinets, closets and bathroom vanities were also made of metal. The prefab homes built in a factory were assembled on-site during the post-World War II building boom.

“They were more resistant to fire, more sturdily built and gave you more for your money,” said Millett. “And were a ready alternative to the stick-built home.”

Holzemer’s Lustron house, built in 1950, is one of six along the 5000 block of Nicollet Avenue S. Millett speculates that the company might have constructed the cluster as a demonstration of its new technology. But the innovative home of the future turned out to be too costly to manufacture and assemble because of its complexity.

Federal government funding was cut off pretty quickly, the company went bankrupt and never gained a foothold in the American housing market, said Millett. Not many of these retro relics remain — there are only about 20 in Minnesota.

Still, the houses are architecturally significant and worth preserving, he said. “Lustrons were well-designed and built, and are nice examples of a little niche of midcentury modernism.”

Today a new generation of prefab home fans are embracing the modest steel-clad ramblers. There are several websites, books, a Lustron Preservation organization and even a documentary.

Holzemer is simply impressed with the Lustron’s nearly no-maintenance qualities and extreme durability.

“The walls are more than 60 years old,” he said. “I’ve never seen a single dent.”

DIY trials and tribulations

In 2008, Holzemer was hunting for a modest house in south Minneapolis and went to a showing. “I’ve always liked modern architecture,” said Holzemer, who has his own film and audio production company. “But I didn’t know it was a steel Lustron house.”

That’s because the exterior was covered in cream vinyl siding. “People wanted to change the color and painted over the metal. Before long it would chip and peel,” he said. “Vinyl covers up the mess.”

Despite the unsightly vinyl exterior, a potbelly stove parked in the middle of the living room and “bad wall-to-wall carpet,” Holzemer decided to take a chance on the simple two-bedroom abode with its hidden retro charm.

“It needed a lot of work, and I wasn’t especially handy,” he said. “But it’s a small house — so how hard could it be?”

Holzemer wasn’t a stickler for meticulously restoring the home to its original state, like some Lustron owners. He focused on updating the spaces, while keeping the minimalist modern vibe. “I’ve made it useful in another era,” he said.

His updates have included replacing beige carpet with wood floors, carving out a TV niche in place of the ugly stove and painting the interior metal walls white. “I’ve never had to drill a hole into a wall,” he said. “I hang artwork and photos with magnets.”

But transforming the vinyl exterior to its original porcelain enameled glory almost pushed him over the edge. After tearing off the siding, he discovered a multitude of drill holes needed to adhere the vinyl to the steel. “I counted over 800 holes,” he said. It took him four weekends to fill the holes with epoxy, a process that he compared to fixing a car chassis.

After that, Holzemer applied muriatic acid to the steel panels in order for paint to adhere. Finally, he mixed two colors to formulate a cool metallic blue-gray hue, and spray-painted the home’s steel box. Although the garage is also clad in vinyl siding, Holzemer won’t tackle that project “until hell freezes over,” he said.

The kitchen, badly “remuddled” by a former owner, was next. Holzemer replaced stock builder cabinets with sleek white Ikea versions. To expand the floor and counter space, he cut a recessed area in the kitchen wall to hold a refrigerator and double oven. “Cutting into steel walls was a nightmare,” he said. But after laying a new tile floor, he’s pleased with the roomier work and eating areas.

His home’s compact spaces are perfect for Holzemer. But a Lustron’s limited size — and only one bathroom — forced Stephen Heller and his growing family to sell their beloved 1949 Lustron home on Cedar Avenue S.

Ten years ago, Heller had moved into the midcentury gem, restoring it with original vintage light fixtures, glass front doors and other materials he sourced from doing research. He even started a Lustron Facebook group to locate resources and “bounce ideas off other Lustron owners,” he said.

Although he sold the property to buy something bigger, Heller will miss what he called “the sleek machine for living ... Lustrons are more sophisticated than the kitsch in a 1950s diner,” he said.

Since the single-story ramblers are built on a concrete slab, there’s no basement for storage or to offer protection from storms. But Holzemer is fine with that.

“I saw a photo of a neighborhood in Texas after a tornado had leveled a block of homes,” he said. “There was one still standing — a Lustron.”