Hawaii Off Grid is using foam scraps to make insulated blocks for housing—a solution that's actually stronger and more energy efficient than the original.
On Maui's North Shore, inside an industrial building that was once a pineapple cannery, an architecture office sits across the hall from a surfboard manufacturer. When the architects first moved in, they noticed something: Every few days, the dumpsters in the back would fill up with scraps of foam from making the boards. David Sellers, one of the architects, realized that the foam could be used in a building material—insulated blocks that are typically made from a mix of concrete and new polystyrene foam. "I was just like, 'We shouldn't be throwing this away,'" says Sellers, principal architect at the firm, Hawaii Off Grid. "We live on an island, with limited space. So how can we use this to make houses?" [Photo: Hawaii Off Grid] In 2023, the team got a small grant to pursue the idea of recycling the surfboard waste into new blocks. Then came the Lahaina fire, which destroyed more than 2,000 homes and other buildings. The small firm paused the project and focused at first on helping redesign houses. "But we also said, we're going to need a lot of building materials," he says. "And we're going to need building materials that are fire resistant." The blocks have some advantages. In addition to resisting fire, they're also four times as strong as a two-by-four framed wall in a hurricane. They're impervious to mold, mildew, and termites,…