Why Floyd Obsessed Over This Detail of Its Ikea-Inspired Bookshelf Easy of use and strength was key to creating a product that would last.

Even if you don't know it, you know Ikea's Billy bookcase. The Swedish retailer's simple 1979 design has sold more than 60 million units -- there's nearly one for every 100 people in the world. "But [many] end up in the trash," said Kyle Hoff, cofounder and CEO of Detroit furniture upstart Floyd.

Hoff and his team wanted to make a shelving unit with the simplicity of the ubiquitous Billy but one that felt more lasting and less disposable. That meant it had to be sturdy but also freestanding, elegant, and endlessly modular -- a difficult combination. Floyd went through 40 iterations of the connection system that attaches the steel shelves to the wooden support stands. One version had a slim profile but couldn't hold enough weight. Another attempt was strong but required four fasteners per shelf. "If you lose one of those pieces, it's going to be a pain to disassemble and reassemble it," he said.

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After six months, the designers found inspiration hanging on the wall of their own R&D lab. The hardware-store shelves they used to store equipment had a hook-and-slot system that needed no additional fasteners and no installation. "It was right in front of our faces the whole time," Hoff said. Floyd's final shelf system uses four verticals lined with columns of slots; the shelves snap into place, allowing consumers to build and add on to their unit both vertically and horizontally. (Want a super-tall, slim bookshelf? You've got it. Want a low, wide configuration? That works, too.) It's a solution Hoff is betting will keep the startup's shelves in homes for years to come -- and far from the Dumpster. (From $400; floydhome.com)