Coffee husks — the coffee bean skins that come off during the roasting process — are one of the main types of coffee production waste, which often becomes a source of potent greenhouse gas emissions when they enter the landfill.

In a bid to divert them from becoming waste, a company in Colombia has found an ingenious way to put them to good use: combining the husks with recycled plastic to create a new building material. Called Woodpecker, the Bogota-based company uses the lightweight strong material to make the walls of its prefab houses — which cost as little as $4,500 per piece.

“We saw that there was a huge necessity for a lightweight construction system for housing and classrooms in rural and isolated places where traditional construction systems cannot go — like bricks, cement, and concrete,” says CEO Alejandro Franco.

After testing a number of different types of natural fibers, the startup eventually landed on using the husks not only because they proved to be more durable than the other candidates, but also because they’re widely available in Colombia — the world’s second-largest coffee producer. The final material, which is a mixture between coffee husks and recycled plastic, turned out to be fireproof, durable, and resist insects.

Using the novel material, the company has developed Lego-like kits that can easily be assembled on-site, with a steel frame and coffee husk boards to click together with minimal tools. The construction of an individual unit takes less than a week.

In order to keep the costs low, the team designed each model of home to use as few parts as possible. The recycled material is also affordable, and Woodpecker lowers costs further by producing materials at a large scale.

Since it launched, the company has been building housing in low-income areas and in places hit by natural disasters where people have been left without a home.