AirCrete Is a Lighter, More Climate-Friendly Version of Concrete for Home Building  

Back in January, in response to the destruction of the Marshall Fire, I wrote about various building techniques and materials, including concrete, that could make homes more fire resistant than today’s common wood-frame tract homes.

Last week a reader shared a recent article on Treehugger.com about AirCrete, “a foamy mixture of air bubbles and cement that is cheap to make, water-resistant, fireproof, and [Do-It-Yourself]-friendly.” Here’s a link to that full article. There’s a 7-minute YouTube video within the article that describes the process.

The process is the brainchild of Hajjar Gibran, the great-nephew of the poet Kahlil Gibran. His enterprise sells the tools for creating AirCrete using locally obtained cement. The only other ingredients are water and your choice of a degreasing dish detergent to create the foam using a 120V foam injection mixer which they sell for $199 on their website, www.domegaia.com. For $95, Mr. Gibran himself will provide a professional AirCrete consultation, or, for $700 tuition, you can attend a 10-day workshop.

Although the organization is focused on building domes, it’s clear that the process can be used to build other types of structures. With total structural building costs in the $2,000 to $9,000 range, the process is marketed specifically for building “tiny homes,” and would, it seems, provide an affordable way of addressing the problem of homelessness. I’d love to see it used here in Colorado!

Regular concrete has a low R-value, the common measurement of insulation — 0.1 to 0.2 per inch of thickness. Because of the air bubbles within it, the R-value of AirCrete is 6 per inch of thickness. This is roughly twice the insulating value of a typical 2×4 wood-frame wall filled with blown-in cellulose.

As I noted in my earlier columns, the manufacture of Portland cement is a major contributor to global warming, responsible for an estimated 7% of all greenhouse gas emissions worldwide. Because AirCrete is mostly air, its use of cement is far less than an equivalent volume of traditional concrete.

According to the Treehugger.com article, “The blend creates a lightweight and low-cost building block that is fireproof, water-resistant, insect-proof, and serves to insulate the building. According to its creator, AirCrete offers many desirable attributes for use as a building material for single-story residences, especially for the owner-builder, among them the ability to cut construction costs by a factor of 10 when compared with conventional construction.”

The article continues: “Beyond its affordability, DomeGaia says their AirCrete is easy to work with, drying in just one night and flexible enough to be shaped into almost any form. You can use your standard wood-working tools to carve or drill into the material, inserting screws and nails where necessary. Since the material hardens as time passes, you can be more confident about the shape you settle on instead of being increasingly worried about future vulnerabilities.”

DomeGaia’s workshops sound like a variation on eco-tourism, because they involve building an actual dome home (probably in a third world country) using AirCrete. Here is an excerpt from DomeGaia’s web page about the workshops:

“This is a hands on workshop, meaning most of the time spent will be outside and actively building. Though there will be some down time when instructors explain the building process and answer questions, you will still be on the building site as these explanations take place, so please come prepared against the elements…. DomeGaia workshops usually include time for yoga, guided meditations, dance, music, and exploring local attractions! Make new friends from around the world, learning, laughing and building together.”

Their website invites you to sign up for a monthly newsletter so you will be notified of upcoming workshops and their locations.

My thanks to the reader who shared AirCrete with me. I welcome your input, too, and let me know if you attend a DomeGaia workshop!

3D Printing Is Being Used to Build Houses for the Homeless With ‘Lavacrete’ Walls

An Austin, Texas, technology company named Icon was the winner of the “general excellence” category in this year’s World Changing Ideas Awards by Fast Company for their development of a 3D printer for building houses.

Their Vulcan II machine is already at work building a neighborhood of homes for Austin’s homeless population and building homes in Mexico for that country’s poor population currently living in shacks. Below is a picture of one of those Mexican homes and a closeup showing how Icon’s 3D printer works, applying layer upon layer of a specially designed mixture called Lavacrete. That product sets quickly enough that another layer can be applied on the machine’s next go-round.

All the walls of a home can be poured in 24 hours spread out over two or three days. The framing of windows and doors and construction of a wooden roof is then done using, when possible, local workers who get on-the-job training, learning skills they can apply in other jobs.

Lavacrete is a propriety adaptation of concrete which overcomes many of the shortcomings of concrete, especially in terms of aging. Because the walls are solid (no room for ducts), the homes are heated and cooled using my favorite method — heat pump mini-splits — which are also far more economical than gas forced air furnaces.

The Mexican project is in a rural area near the southern city of Nacajuca under a partnership with New Story, an international non-profit whose mission is to “pioneer solutions to end global homelessness.”

I remember seeing TV footage showing Icon’s 3D printing machine at work. Prior to that, I attended a presentation by New Story at the Rotary Club of Golden, which, as I recall, joined Rotary International in providing financial support. I am proud to be a financial supporter myself, and you can do so too at www.NewStoryCharity.org.  

3D printing of homes makes sense. I have seen how 3D printers can build various products applying layer upon layer of resin as instructed by a computer program. As with those table-top machines, all that’s needed to build the interior and exterior walls of a home is a larger flat surface (a concrete slab) and a massively larger printer to float above it. Taking the process to yet a higher level, Icon has successfully built the walls of three side-by-side homes simultaneously in Austin, which is impressive and, of course, more cost effective. Here’s an aerial view of 3D printing at work:

Partnering with local non-profits and using local materials and laborers, New Story delivers its fully finished homes free to the Mexicans it is serving, but I can see it being practical in our country to offer such homes with low-cost mortgages and nominal down payments to the homeless or working poor. 

The homes built by Icon for the Austin non-profit Mobile Loaves & Fishes were permitted by that city. When fully built out, their Community First Village will house an estimated 480 formerly homeless individuals, representing 40% of that city’s chronically homeless population.

Many Organizations Contribute to ‘Rapid Shelter’ Effort Addressing Homelessness

Homelessness is an increasing problem in Denver and around the world, thanks in part to the financial effects of Covid-19, including rising unemployment. Like me, you have probably seen news reports about homeless encampments in Denver, wondering what can be done to address what appears to be an intractable problem.

As a committed capitalist and entrepreneur, as well as a would-be philanthropist, I know there are solutions to this social challenge, so I was pleased to come across a Fast Company article with the headline, “45 innovative solutions for beautiful, easy-to-build housing to help cities with the homelessness crisis.”

That article was inspired by the Rapid Shelter Innovation Showcase, “a clearinghouse for smart ideas on how to lower construction times for cities in need of new housing for people living on the street or after a disaster.” You’ll find the showcase on the website of The Housing Innovation Collaborative, created in 2019 by several Los Angeles non-profits committed to addressing homelessness in L.A. and around the world.

According to their website, “almost one million people [in L.A.] live on the verge of homelessness, and 60,000 people are homeless on any given night. Just to sustain ourselves, we need to build over 500,000 affordable housing units and increase our current housing production by 4.5x.

The cost per bed of the 45 concepts, many of which are described as “in stock,” ranges from under $1,000 to over $100,000. Others are described as “con-ceptual ideas only” or “nearly ready.” with days required to set up each product ranging from 1 to 90 days. Eleven were described as ”built prototypes only.” Each has a link to its own web page with complete information.

Previously I have written about the “tiny home” movement, and I’ve visited several tiny homes, including one on the annual Boulder Green Home Tour. A few years ago, several tiny homes were displayed in the parking lot next to the Golden Public Library, and last year there was a display of them (which I missed) on open land off Pena Boulevard.

Tiny homes are intended to be permanent housing. They have complete kitchens and bathrooms, requiring hook-ups to water and sewer, although some are available as trailers requiring only the occasional RV hook-up. But most of the solutions displayed on the collaborative’s showcase are intended to get homeless people out of tents.

It’s hard to describe the variety of technologies and styles in the showcase, so I’ll show just a few of them here, but each picture below is a link to that entry’s web page.

NYC Emergency Housing Prototype can be built in less than 15 hours. Cost: $156,000, 6 beds.
 
IndieDwell, a Boise-based company, offers this 2-bed unit built from an 8’x40’ shipping container for $50,000. Setup time is 18 days.
 
You can buy this 2-bedroom 600-sq.-ft. in-stock kit home from Sunshine Network Homes, Inc. for $53,642. Setup time is estimated at 29 days.
 

Not mentioned in the showcase is a  British charity called ShelterBox, which I learned about as a Rotarian. Their containers, easily carried by two persons, are warehoused around the world, ready to be deployed quickly to disaster locations. They contain a tent and other aid items such as mosquito nets, water filters, water carriers, solar lights, cooking sets, blankets and mats. It is a charity worthy of your support. Learn more at www.ShelterBoxUSA.org.

As the Housing Crisis Deepens, Zoning Laws Are in the Crosshairs

In December 2018, Minneapolis made news when it abolished single-family zoning. That began a nationwide conversation about the use of zoning laws to restrict growth and density at a time when housing affordability was worsening and homelessness was increasing.

One of our broker associates, Chuck Brown, attended the National Association of Realtors convention last November in San Francisco. I had attended the same convention there several years ago. I hadn’t noticed many homeless people on the streets back then, but Chuck reported that it was way out of control now, with the streets overcrowded with homeless people.

You, like me, have probably followed the coverage of homelessness in Denver, with that city passing an urban camping ban, which was ruled unconstitutional by a lower court but is still being enforced pending an appeal by the city. It could go all the way to the Supreme Court.

The conversation over zoning created by Minneapolis 13 months ago is growing louder. That’s because the history of zoning is one of intentional discrimination. In researching this topic, I read a Fast Company posting on the history of zoning in San Francisco.. After the 1906 earthquake, the Chinese population there was targeted by zoning changes designed to promote and protect white enclaves. This was long before there were federal laws making discrimination based on race or national origin illegal.

That Fast Company article included the following detail regarding the role of the mortgage industry: “In 1934, as part of President Roosevelt’s New Deal, the Federal Housing Administration (FHA) was established to insure private mortgages. The FHA’s underwriting handbook included guidelines that pushed cities to create racially segregated neighborhoods and encouraged banks to avoid areas with ‘inharmonious racial groups,’ essentially meaning any neighborhood that wasn’t exclusively white.”

Another New Deal program to help homeowners threatened with foreclosure to refinance their home with low-interest long-term mortgages, provided lenders with “safety maps” which used red shading for risky areas which were under “threat of infiltration of foreign-born, negro, or lower grade population.”  This is the origin of the term “redlining,” and the practice wasn’t outlawed until the Fair Housing Act of 1968.

Last week I attended a meeting of the Group Living Advisory Committee in Denver’s municipal building, where they are discussing a zoning amendment which would dramatically increase the number of unrelated persons who can live in a single family home. You can expect this proposal to arise in suburban jurisdictions, too, even if they don’t follow Minneapolis in getting rid of single-family zoning altogether.

I’ll be reporting again as this conversation evolves. Don’t shoot me. I’m just the messenger.