Living in a 3D Printed House

Housing is expensive. In fact, a home is often the most expensive purchase of a person’s life. To address the increased cost of housing, people have come up with some creative options. There are modular and manufactured homes for example that are built in a factory and then assembled on site. Efficiencies created in the factory can lead to reduced costs. There’s also an active movement in our country right now where people are relocating into tiny homes. Smaller spaces can be more energy efficient, offer a simpler lifestyle, and because they involve fewer materials and labor, are less expensive.

Still others have found ways to repurpose non-traditional materials into homes such as shipping containers, wood pallets, or even building a home with earthen materials, such as using a cave or cliffside for one or two of your walls. A particularly interesting approach that’s gaining some traction at the moment are 3D printed houses.

What is a 3D Printed House?

A 3D printed house may sound unusual, but it’s just what it sounds like. It involves a giant 3D printer that literally pours the building material by moving back and forth one layer at a time. After the first row or layer is completed, the printer goes back and pours another layer on top of it. This process continues until the full height of the walls are completed.

To be fair, when we talk about the 3D printed component, we’re really just talking about the walls. Builders still use traditional windows, doors, and roofing to complete the home. Printing a roof would be more challenging since it’s not vertically positioned and is frequently pitched. Similarly, the material used for the walls which is like concrete can’t replace a transparent glass window. Thus, while the walls can be printed, there are aspects that still must be built using more traditional materials and methods.

3D printed homes can be as small as 400 square feet and in other instances exceed 3000 square feet. Currently, there are only single-story 3D printed homes. This has to do with the novelty of the technology and the practicality of getting the printer physically high enough to print taller buildings. The printer pours material downwards out of a spout and so it must be above where the walls are to be built.

Once the design, permitting, and provision of materials have been addressed and the printer is on-site, the actual printing process can be accomplished in only a few days. For example, a 450 square foot home in Austin, TX was built in under 48 hours.

The Material

The walls themselves are made of a concrete-like material. Though not all companies use the same material, one common one is a polymer known as Lavacrete. Lavacrete consists of pulverized lava rocks, cement, and water. It forms a semi-fluid material similar to concrete, which allows it to be poured from the printer before solidifying. Lavacrete provides three times the bond of traditional concrete.

Additionally, it can handle a compressive strength of over 2000-3000 psi, making it very resistant to natural disasters. Another product, similar to Lavacrete boasts a strength of 6000 psi.

The use of concrete mixes also makes for a more environmentally friendly material. The raw materials can be locally sourced, the printers use very small amounts of energy, and the concrete mixes help to reduce embodied carbon. This is in addition to the fact that the thickness of the walls provide a lot of insulation, helping to regulate the indoor temperature and reduce the need for artificial heating and cooling.

Strength

Like all housing, a 3D printed home must be safe for human habitation. This means meeting or exceeding building codes. The biggest challenge for builders has not been safety or the ability to meet building codes, but simply the fact that the technology is new. This means that city officials are not generally familiar with the process, the material, the R-values that can be expected, etc.

One way to think of the strength and safety of a 3D printed home is to compare it to wood construction. Most single-family homes are built using wood, and wood is weaker than the concrete mixes used by 3D printing builders. Concrete is also more resistant to fires, damaging weather conditions, and pests such as termites.

Though not totally impenetrable, the concrete mixtures used are much more capable of handling wildfires, high winds, extreme temperatures (both hot and cold), floods, and earthquakes.

Additionally, it’s a safer methodology for the builders as well. The concrete mixture is handled by a machine. This leads to fewer worker injuries such as falls and accidents with power tools.

Though time will tell, the estimate is that these homes will last 50-60 years.

What about the Cost?

Since homes are unique, it can be difficult to give a precise cost. However, let’s take a look at a few examples just to get an idea.

A 750 square foot home in New York State was listed for $300,000, approximately half the cost of comparable properties in the area. Another company builds home ranging in size from 800 to 1400 square feet, with a starting price of $190,000.

There was a hybrid home in Texas, using both wood, 3D printing, and other materials, for a unique aesthetic blend. This home was priced at $450,000.

As already alluded to, factors like the cost of permitting, access to materials, labor costs, the type of concrete mix used, and builder markups will affect pricing. The printers themselves can also vary significantly in cost, an expense that will naturally be included in the purchase price. Also, let’s not forget market conditions. Even if a builder can build the same exact house for the same price, a home selling in San Francisco will probably cost more than one in Little Rock.

Still, there is the potential for significant cost savings. In some cases, tiny homes can be built for as little at $4000 - $10,000. Keep in mind however that that’s simply the cost of construction and not the actual price tag.

Like most technologies, when it’s new, it’s more expensive, and the printers, which represent the most expensive component of the build, will likely come down in price with time. Still, if the construction of a 400 square foot home can cost $10,000 or less, there’s certainly potential. Habitat for Humanity and other nonprofit organizations have already gotten involved as they explore 3D printing as a possible means of providing more affordable housing options to low-income families. Naturally, time will tell if 3D printing is the future of housing or simply another idea that sounds great in theory, but when faced with the challenges of reality proves to be simply another option.

The Experience

While most people have never been inside a 3D printed home, there are some people currently living in one. The consensus seems to be that residents feel the homes are secure, with thick walls and a tight feel.

One person explained that while it may feel like a fortress in some respects, it doesn’t have a closed-in feel. He went on to say that it provides a sense of safety and quietness in that you can’t hear through the walls.

Another individual mentioned liking the energy efficiency, stating that even though they live in Arizona they rarely have to turn on the air-conditioning and when they do, they can usually turn it off after only a few minutes.