Designer Ryan Frank wanted a semi-mobile home for a small plot in a “sensitive area” in Spain. He thought about yurts and domes, but settled for an open source design he found online. Often called a “boathouse” or “gothic arch” structure, it was originally developed by a boat builder; it’s centerpiece are the wooden support ribs.

Frank built the home for about 1000 euros in roughly 100 hours. He now lives in it full-time with his girlfriend, though they use a separate camper as a kitchen, as well as a separate composting toilet and outdoor shower.

* A video on Frank’s DIY recycled container lampshades.