The eco-designer was raised on a farm in Luxembourg, and she’s brought a feeling for the natural world to her residence in Barcelona, Spain. “Growing up on a farm influenced my ideas,” she explains. “There it was all about life cycles, materials that flow, eating, composting, growing...” Scholtus, who also runs her own sustainable-products studio, Pöko Design, moved to Barcelona in 2004. Three years later, she and her partner, Sergio Carratala, a structural engineer, found a nearly-625-square-foot apartment in an 18th-century building at the heart of the Barri Gòtic. Their plan was simple: Use eco-friendly and recycled materials, reduce water and energy consumption and create as little waste as possible. While sacrificing neither aesthetics nor comfort, Scholtus has accomplished that and more. There are cabinets made from wooden wine boxes, cork floors installed without glue, PVC-free pipes, secondhand furniture and even a worm-composting enterprise on one of the tiny balconies. No detail was too insignificant—witness the Staple-Free Stapler in the office.

The couple documented the renovation on their blog, and though Scholtus pronounces it complete, she’d like to find room for a dishwasher (“If used correctly, it saves more water than washing by hand”), and she’s waiting for LED and OLED lighting technology to become more accessible. And then there’s the matter of space for overnight visitors: She and Carratala envision a fully recyclable, folding wall to create an impromptu guest area in the living room.

Scholtus dreams of eco-design that is readily available—and economical. “When done right, designing sustainably is not more expensive or uglier,” she says. “You just have to be that extra bit more creative.”