Building a house by hand can be both time-consuming and expensive. Numerous homebuilders have chosen to automate part of the construction (i.e., by printing the home’s parts) instead.

A new Ukrainian homebuilding startup called PassivDom uses a 3D printing robot that can print parts for tiny houses. The machine can print the walls, roof, and floor of PassivDom’s 380-square-foot model in about eight hours. The windows, doors, plumbing, and electrical systems are then added by a human worker.

When complete, the homes are autonomous and mobile, meaning they don’t need to connect to external electrical and plumbing systems. Solar energy is stored in a battery connected to the houses, and water is collected and filtered from humidity in the air (or you can pour water into the system yourself). The houses also feature an independent sewage system.

PassivDom’s homes, which start at $31,900, are now available for preorder online in Ukraine and the US, and the first ones will be delivered later this year.

Check out the homes below.

PassivDom’s smallest model measures 380 square feet and costs $31,900, designer Maria Sorokina tells Business Insider.

Here’s what the house looks like when you walk in the front door. It’s a large open space with a small kitchen and floor-to-ceiling windows.

This model doesn’t include a separate bedroom, which means residents need a sleeper sofa. A small bathroom is located near the kitchen.

PassivDom offers three models of homes and can make custom models as well. The premium models come with furniture, but the one pictured below comes unfurnished.

The homes also offer the possibility of living off the grid.

“We should have opportunities to live in nature away from civilization, but have comfortable conditions of a traditional house,” Sorokina says. “This technology can allow us to live in the woods, on mountains, or on the shore — far away from people and infrastructure.”

To make a PassivDom home, the team maps out the plan for the 3D printer in its factories in Ukraine and California. Layer by layer, the seven-axel robot prints the roof, floor, and 20-centimeter-thick walls, which are made of carbon fibers, polyurethane, resins, basalt fibers, and fiberglass.

Doors, windows, appliances, an alarm system, solar panels, and the septic, electrical, healing, cooling systems are then added.

Depending on the model, the whole process can take under 24 hours. The design and production of larger houses with more specifications and finishes, like the one below, can take up to a month. If a house is premade, it can be shipped the next day.

The startup believes 3D printing is a cheaper, more efficient way to build homes that it can sell at a (relatively) affordable price. “Over 100 million people do not have a roof over their heads,” Sorokina says. “It is necessary to build more affordable houses.”

PassivDom is not the only company using 3D printing to build homes. The San Francisco-based housing startup Apis Cor, Dus Architects in Amsterdam, as well as Branch Technology from Chattanooga, Tennessee, say they can construct homes in mere days or weeks.