When David Schafer moved into his 426-square-foot San Diego rental in 2003, the Chiclets-sized floor-plan wasn’t exactly a deal breaker. At six foot three, he found the live-work loft’s double-height ceiling a plus, and the aspiring architect geeked on the building’s pedigree: the Merrimac, built in 1999, was one of the first modern, mixed-use redevelopment projects in San Diego’s formerly blighted Little Italy neighborhood. (Plus it was featured in the very first issue of Dwell.)

But when David, 31, and his now-wife Im, 26, discussed living together (they met in college, both pursuing degrees in architecture), making smarter use of the vertical space became a priority. Make that a necessity: The previous tenant was a bachelor with Spartan tastes, and with a 260-square-foot outdoor deck and sleeping loft, the place was perfectly adequate—as long as you didn’t own any stuff. Like books. And clothes. And food. All of which David and Im owned and used pretty much every day. “When we moved in, we had the range, the sink, and the refrigerator, and that was it,” says David. “Everything else we made ourselves.” Their solution was storage; and they had nowhere to go but up. The result has been an ongoing collaborative project, an experiment in extreme design and domestic tranquility.

The first thing David did (with help from his dad) was build a corrugated-steel workshop out on the deck, from whence most of the loft’s interior fittings have sprung; only heavy-duty metalwork was completed off-site. The shed’s obsessively orderly jars of sheet-metal screws and neatly coiled extension cords are a pretty good metaphor for the inside of David’s skull: This is a man who makes CAD drawings of his spice collection. Im is an organizer, too, though the flavor of her fervor differs. While David is an inveterate collector, disassembler of machines, and obsessive cataloguer (“I call him an ‘objectician,’” says Im), her neatness is more visually oriented. “I need to make sure I know where everything is,” she says. “I need to see it to keep it in order.”

The couple’s proclivities are enshrined in the kitchen area, where shelves computer-calibrated to their con-diments and liquors climb the wall behind the bare-bones appliances, warmly lit by halogen spots like an alterpiece to Our Lady of the Garlic Press. Frugality and ingenuity harmonize in IKEA drawers fitted into frames made of construction lumber and cold-rolled steel from the local Handy Metal Mart, and galvanized boxes from The Container Store spot-welded together to fit silverware and utensils.

Because the loft is a rental, everything they’ve built has to be removable; and because David and Im are smart, all the best stuff is recyclable. Accordingly, their choices of construction materials are as carefully meas-ured as their calculations of spatula and pasta lengths: “If it was a material we could reuse, we opted for some-thing more durable and more expensive; if it would only work for this space, then we defaulted to the cheapest material we could find,” says David. The kitchen shelves—which will stay—are unstained, unfinished MDF plywood, while the countertops and dining table—which will move on to their next abode—are heavy-gauge stainless steel.

And then there’s the “Wall of Storage”: A five-columned steel structure that occupies the entire west wall of the loft and contains everything else the couple owns—piled 20-feet high. David explains the painstaking planning that went into making the freestanding behemoth rental-friendly: “We screwed plywood to the ceiling, and then bolted the steel structure to the plywood, which serves as a membrane. So this massive thing just sits on the ground.” For those thinking of trying this at home, consider that David has a chummy relationship with his landlord. “He’s an architect, so we speak the same language,” David says. “In our minds, this qualifies as furniture.”

The Wall of Storage is not just a wall of storage—it’s a machine for daily living, an office, a TV room, and a walk-in closet that’s as aesthetically pleasing as an American Apparel window display. Though their T-shirts are arranged by color, Rain Man–style (“If you had to stare at your closet every day, you’d do it, too,” says Im), there’s a 13-foot cotton curtain that can be pulled to hide it all from view. “Guests can be out here,” says Im, indicating the living area, “and I can still be getting dressed back there—it connects straight to the bathroom. And if we have an overnight guest, we basically have our own bedroom.” Sometimes, at the very top of the Wall of Storage, hibernating in a shoebox, is Atlas, the couple’s California desert tortoise—the ultimate neatnik’s pet: This gentle and noble creature spends half its 80-year life span asleep, and its (infrequent) waste products are easily swept away.

If the Schafers possess any latent messiness or packrat tendencies, they’re forever entombed in the Wall of Storage, inside clear plastic bins and big, green rubber totes placed up top for the heavy, infrequently used stuff. Seismically sensitive visitors invariably question the wall’s stability. David asserts that since the bins rest on parallel bars of steel, any sizable temblor would just cause them to tip conveniently into the gap, wedging them tight. And as long as the engineer is also the guinea pig, who’s to argue?

But this is where the Schafers’ evangelism about their project shows, revealing their apartment-as-experiment to be a little less grad-school-application fodder, and a little more Unabomber Hut (but in a good way). The couple believes fervently in what they’re doing—call it an exercise in Extreme Shelving, pragmatic Minimalism, or just plain neat-freakiness—as evidenced by the rigor of their calculations and the mental and physical energy they’ve expended. And it’s obvious that they truly enjoy living this way, scrambling like spider monkeys to reach all their artfully arranged stuff, from books and clothes to the gaggle of frayed Eames shell chairs hanging above the entry, like moose heads in a hunting lodge. In this sense, the two budding architects are part of a long line of artists who adjust their surroundings to jibe with their quirky mental furniture, and an equally storied tradition of pioneers—from Marie Curie to Frank Gehry—who’ve experimented on themselves, as the cheapest, least annoying, yet most demanding client they’ll ever have.

David and Im readily admit that their style of living isn’t for everyone. “The space wasn’t intended or designed to work for anybody but us,” says Im. “It’s a little case study for ourselves, to see what we can get away with,” adds David. He pauses. “Honestly,” he says with a grin, “I think we could live in less space.”