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!

Do You Practice Sustainability? Home Renovation Can Be Done Sustainably, Too

Tonight is the fifth in Golden Real Estate’s Sustainability Series. Previous sessions were about home insulation (January), home heating technology (February), solar power (March), and electric cars (April).

This month, the topic is sustainable renovation. Our presenter is an expert in sustainable practices when it comes to home renovation.  His name is Steve Stevens, and he has been my mentor regarding sustainable practices for nearly two decades.

A retired scientist from Bell Labs, Steve has made a lifelong project, it seems, out of reducing the carbon footprint of his 1970s brick ranch in South Golden.

Retired and living on a fixed income, he has developed several habits/practices that are not only sustainable but also have saved him a boatload of money.

For example, he only buys cull lumber from Lowe’s, and he buys returned products (typically mis-ordered) such as windows  and doors, which are then sold for a fraction of their original price.

Steve also seeks out salvaged goods such as windows and doors. As with buying cull lumber and returned products, collecting salvaged products means zero new carbon footprint for doing your renovation. 

Steve, being a scientist by training and passion, always considers the embedded carbon footprint of products, whether it’s food or building materials. How much energy is used to transport the goods you purchase?  For example, are you buying slab granite mined and shipped from Asia, or an alternative material mined or created closer to home?

Steve will share his shopping and construction tips that save money and are also sustainable.

For example, he emphasizes insulation, which should always be your first measure when it comes to saving energy. But what products should you buy, and where should you start?

The session will be held tonight, May 16th, from 5 to 6 pm in the Golden Real Estate office at 17695 S. Golden Road, Golden. There are still seats available. Reserve yours by emailing me at Jim@Golden RealEstate.com

Each of our sessions is video recorded by our friend, Martin Voelker, from the Colorado Renewal Energy Society.  You can watch videos of the first four sessions at Sustain-abilitySeries.info.  This session will also be recorded and posted there.