11/08/2012 10:57 am ET Updated Dec 06, 2017

WATCH: 325-Square-Foot Tiny 'Cave' Apartment With DIY and Upcycled Furniture

Tammy Strobel

Monica Potvin and Markel Otaola bought the 30-square-meter (323-square-foot) apartment in Barcelona's Gothic Quarter during their child-free years, when location was more important than space.

The tiny quarters had once been a space for the doorlady, and it was half underground. After a makeover that included a lot of custom, DIY furniture, Potvin dubbed the home the "cozy cave."

The couple lived here while Potvin was pregnant* and have even hosted dinner parties in this reduced volume. Thanks to some dual-purpose furniture, the place now sleeps four. In addition to the queen bed in the bedroom, there's a couch bed for one in the living room and a nook under the stairs where the couple crafted a mattress on top of what was once a little-used ledge.

Much of the home is custom, and all was crafted by the creative couple. Potvin found an old pallet on the street and covered it with plastic to create a stylish coffee table (with space for magazines and books between the wood). A salvaged door is now the hallway mirror, and old airplane food storage carts serve as bedside tables.

Many items are half-sized, like the bathroom sink and the refrigerator, but Potvin doesn't view the space as less enjoyable than the huge apartment she once rented in New York. "You just don't bring much stuff in, I think that's the difference. You buy food for the next few days -- maybe you're more in the moment, more kind of basic and in the moment."

* The couple now live in twice the space across town with their three-year-old son (see our video Tiny home cube: bathroom + kitchen + closet for family of 3)

Watch Kirsten's feature-length documentary on tiny homes, We the Tiny House People: Small Homes, Tiny Flats & Wee Shelters in the Old and New World.