November 27, 2022


We Do Fine Home

Unveiled at SXSW: Texas architecture firm Lake

AUSTIN — The three-bedroom, 2 ½-bath house recently built in east Austin has all the earmarks of a mid-century modernist Texas ranch: clean lines, large windows, a flat roof and plenty of wood, inside and out.

But the house, designed by the Austin office of San Antonio-based Lake | Flato, was built using a large-scale 3D concrete printing system developed by Icon, an Austin-based home-building company. It was constructed as a demonstration project to illustrate the promise of Icon’s 3D printing technology to build high-end yet sustainable and energy-efficient homes.

The house’s most arresting design elements are the curved exterior walls that have been compared to tree trunks and elephant legs. They’re made from Icon’s proprietary cementlike material called Lavacrete that is extruded by the printing machine like a thick squeeze of toothpaste and stacked in layers like a coil. The result looks unlike anything constructed using traditional building materials.

3D printing technology uses a computer-created designs to build three-dimensional objects such as furniture, automotive parts, toys and sculptures in layers out of a variety of materials. In this instance, the technology was used to form both the interior and exterior walls, like an adobe house. The rest of the house was finished out using more traditional construction methods.

This is the first time Lake | Flato has designed a 3D-printed house, according to Ashley Heeren, an architect in Lake | Flato’s Austin office and co-lead on the project with associate partner Lewis McNeel.

“We’re involved because Icon invited us, and we loved their aspiration to take the concrete printing technology that they’d been working with into a different market, a different aesthetic,” she said.

Dubbed “House Zero” and owned by Icon, the house is a showcase for how the company’s 3D wall printing system can be used to more sustainably construct single- and multi-family homes. It is also intended as a potential answer to societal issues such as chronic homelessness and the need for fast, emergency housing following natural and man-made disasters.

“My hope is that this home will provoke architects, developers, builders, and homeowners to dream alongside Icon about the exciting and hopeful future that robotic construction, and specifically 3D printing, makes possible,” said Jason Ballard, co-founder and CEO of Icon in a statement. “The housing of our future must be different from the housing we have known.”

When the house opened for tours during this year’s South by Southwest conference and festival, it was so popular, there was a wait list.

Closeup of the layers of cementlike Lavacrete used to construct the 3D printed house.

Closeup of the layers of cementlike Lavacrete used to construct the 3D printed house.


After the house foundation was poured, a large gantry, a bridgelike structure that supports the Lavacrete nozzle, was brought to the job site and fixed onto rails. Moving side to side and up and down, the computer-controlled nozzle extruded the Lavacrete layers, building the walls according to the architectural plan.

Building a house this way eliminates five to six steps of a typical “sticks and bricks” home construction, according to Cara Caulkins, a spokeswoman for Icon.

“There is not an ounce of Sheetrock in this home, so from a sustainability point, there’s way less waste on a home that’s 3D printed,” she said.

The process also improves a home’s energy efficiency. R-value is a generally accepted measure of a material’s insulating properties and the Energy Star program’s recommendations for exteriors walls are R-13 to R-23. The Lavacrete walls are rated at R-40.

“And the rest of the wall systems within the home are well above minimum code requirements,” Caulkins said.

The undulating walls serve both aesthetic and structural purposes. While they help support the structure, they are also used to create ground-level planters on the outside of the house. Inside, they formed three small niches off the large central living area, one for a dining nook, another a small seating space and a third for a tidy home office.

“This was one of those opportunities to use the technology to create different types of spaces,” Heeren said. “That would not make sense with any other material.”

A Murphy bed in the casita converts the living area into a bedroom.

A Murphy bed in the casita converts the living area into a bedroom.

Richard A. Marini /Staff

Inside the house, walls that are not made of Lavacrete are Douglas fir, hung as panels that provide a softer, richer counterpoint.

The Lavacrete can be painted, but in this house it retains its raw, gray color, although subtle differences in each day’s batch of concrete creates slight variations in the shading of the individual layers.

The only room in the house without walls at least partially 3D printed is the kitchen, which has large windows overlooking the small backyard and will soon be screened from the neighbors once the vines planted along the fence grow in.

“We let the kitchen stand on its own as one other experience within the overall house,” explained Heeren who added with a laugh, “although actually, the countertop is concrete — but not 3D printed.”

In several places, including the powder room and the owners suite shower, a plaster product was applied inside of the curved inner walls of the Lavacrete.

“The plaster smooths out the surface and creates a more continuous curve with a different finish,” Heeren said. “It was fun to play with the plaster. With the shower, we were like, ‘Why not make it round?’ It showcases the shower in a different light, and with no hard corners, it’s easier to clean.”

The house also includes a separate, 350-square-foot casita that has a full bathroom, a small kitchen and Murphy bed to convert the living area into a bedroom. Its walls also were built with the 3D-printed Lavacrete.

Icon would not disclose the construction cost of the house, and representatives say they have no plans to sell it. Instead, it will continue to be used as a proof-of-concept demonstration project. Similarly sized, albeit traditionally constructed homes in the east Austin neighborhood are valued at $700,000 and up, according to the real estate website Zillow.

House Zero is not open to the general public, although it is visible from its location on Riverview Street. Those involved in the building industry can reach out to the company at to inquire further.

[email protected] | Twitter: @RichardMarini