A tiny California start-up is looking to printers to solve the housing crisis—actually, a very large 3-D printer.

The company, Mighty Buildings, has been showcasing small (350 square foot) studio apartment models of its new "ADU" units (Accessory Dwelling Units) aimed at backyards and selling for around $115,000. That is, if you do the work and deal with local governments to get all the permits, connect the utilities and install the unit. Have Mighty set it up for you, and you're looking around $184,000.

Sam Ruben, the co-founder of the firm, says Mighty can have the home in place in just over two weeks. He credits a super-large (43x20 feet) 3-D printer for being able to generate the materials for the frame, using a gel that hardens instantly when it gets hit with light. Robotic arms scan the objects and pour the gel.

Mighty has just gotten started, and is finishing the first of several homes in the San Francisco Bay Area and San Diego. But Ruben has big plans.

He predicts some 100 homes will be created by the firm in 2021, followed by at least 1,000 the following year.

Ruben said the idea was hatched as a way to help solve the . By using 3-D printing and new technology Mighty can dramatically speed up the construction process.

ADU's are easier described as an accessory dwelling unit, a detached or an attached building that goes into a backyard or a side yard of an existing residence. ADUs are usually considered a guest house or extra living space that can go into the Airbnb rental pool.

Mighty calls itself a "modular prefab construction company" and says it is fully compliant with all aspects of the California Building Code, including Title 24 Energy and other standards. The company offers a standard 10-year warranty on all the structural systems.

He compares it to the Sears kit homes from the earlier part of the last century, which came preassembled, and were put together by the home owner with hammer and nails—and help from the neighbor.

The difference is the construction process can move so much faster. "It shouldn't take months to build a ," Ruben said. "We can do an entire shell in one day." It takes two weeks to complete a studio and three weeks for the one-bedroom model, which starts at $160,000. All units come with combo washer-dryers, a dishwasher and a tiny kitchen.

Mighty currently has only one printer in operation, but it is in the process of adding more.

"The long-term vision is to have factories, minimize logistical costs and create a new class of jobs," Ruben said. "Right now, we don't have enough people to build all the homes (in traditional construction) ... We hope to create a new generation of workers."

Ruben said the 3-D printed wall responds just as normal drywall does in that you can put nails and screws into it and his tests show that it will stand up to rain and hurricane.