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!

56% of Americans Say They’d Live in a Tiny Home  

Treehugger.com is an interesting website which was brought to my attention because of a Dec. 28 posting entitled, 2021 in Review: The Year in Tiny Living.” 

The article contains 10 stories about tiny homes that make great reading and may inspire you to consider building your own tiny home. The headline above was item #1.  Here’s an excerpt from it:

“…Oft-cited factors behind the appeal of tiny houses include efficiency, eco-friendliness, the minimalist lifestyle, the ability to downsize, with the top motive being affordability, as 65 percent of respondents indicate. Of those surveyed, 61 percent say they would spend $40,000 or less on a tiny home, compared to 16 percent who would spend more than $70,000. Seventy-nine percent say they would be able to outright buy or finance a tiny home, rather than a traditional starter home.”

Here are the titles of the other nine articles. Click on them to read the full article:

Young Biologist Builds Her Own Tiny House for $30,000

This Steel-Clad Tubular Cabin in the Woods Is Built Like a Ship

Couple’s Extra Wide Tiny Home Features Mudroom & Ergonomic Kitchen

> Family’s Fabulous Bus Conversion Has Play Loft and Roof Deck

Adaptable Furniture & Mirrored Walls Enlarge a Compact Apartment

This Ambulance Conversion Is a 4×4 Overland Rig With Shower, Toilet and Hot Tub

Young Couple Builds Sprinter Van Home for $8,000

> A Shipping Container Home That Makes Sense.

Small Parisian Apartment Revamped With Clever Space-Saving Staircase:

Here’s More About Our Planned ‘Net Zero Store’  

By the time you read this article, Golden Real Estate’s move from 17695 S. Golden Road to 1214 Washington Avenue will be well underway.

Last week I announced that we will be transforming our old office space (which Rita and I own personally) into the home of a new venture Ty Scrable and I are calling The Net Zero Store.  It will be a one-stop shop for “all things sustainable,” selling and/or brokering products and services designed to reduce your home’s carbon footprint.

Among the products we will be selling or promoting are the following:

Solar Photovoltaic and Solar Thermal Systems

Sun Tunnels

Heat Pump HVAC Systems

Heat Pump Water Heaters

High-Efficiency Windows

Various Kinds of Home Insulation

HRVs and CERVs for Home Ventilation and Air Quality

Induction Cooktops

Condensing Clothes Dryers

Sustainable Countertop Choices

Electric Vehicle Charging Stations

 Among the services we will offer directly or through vendors are the following:

In-Home Consultations With a Sustainability Coach

Energy Audits

Blower Door Testing

Testing and Mitigation for Mold, Radon, Asbestos

Advice Regarding Electric Vehicles

ADUs and Tiny Homes

Webinars and In-Person Events on All Aspects of Sustainability

Reading/Video Lists for Further Study

Styrofoam Recycling

Unlike other stores, everyone you encounter at The Net Zero Store will be knowledgeable in all these areas. Ty and I are in the process of creating partnerships with vendors of these products and services. If you have a product or service you think should be featured in our store, please call Ty at 720-281-6783.

We are also recruiting volunteers to serve as sustainability coaches.

Manufactured and Modular vs. ‘Stick-Built’ Homes: Here Are My Thoughts

There has been some confusion in the real estate world over the term “manufactured” homes. Most recently the term has been applied to mobile homes — also referred to as single-wide or double-wide homes, which are transported fully finished to mobile home parks.

But “manufactured,” as I understand it, can be applied to a home whose walls, trusses and other components are put together in a warehouse, then shipped on flatbed trailers to a construction site where they are assembled and installed on a standard concrete foundation.

A “modular” home goes a step further, in that entire rooms might be assembled in a warehouse, transported to a work site and then assembled with other modules to make a complete house.

The first home I bought in Colorado was a ranch with walk-out basement in Golden’s Mesa Meadows subdivision. Only after I had moved in did a neighbor share with me how my home was put together in a day or two. Its components were manufactured in Fort Morgan and delivered to Golden only after the concrete foundation was ready to receive them. Anyone looking at the home would think it was a  “stick-built” home like the other homes in the neighborhood. When I bought it and when I later sold it, it wasn’t listed on the MLS as “manufactured,” because that would have felt like a misrepresentation, given the type of home it was.

The neighbor who explained that my home was actually built in Fort Morgan and assembled on site, explained how that process made for a better home. The exterior walls were 2×6 construction (to withstand the rigors of shipment) and they were fully insulated on the factory floor rather than on-site, resulting in better quality control. It made sense to me. It also made me wonder why more homes aren’t built that way.

I remember learning that an affiliate of Habitat for Humanity in Minnesota or Wisconsin constructs homes that way during the cold winter months — having volunteers assemble entire wall units in heated warehouses during cold spells, then delivering them to the site later on.

Every conventionally built home uses roof trusses that are made to order on factory floors and shipped to work sites on flatbed trailers, so why not have wall units made to order as well?

From 1933 to 1940 Sears Roebuck sold mail-order “Kit Homes” that were “pre-cut and fitted.” A 2-story colonial-style home called the “Martha Washington” was sold by Sears for $3,727. Other kit homes had names like the Cape Cod, the Ridgeland, the Franklin, the Dayton, and the Collingwood. See below for that model’s description from the Sears catalog. Many homes in Denver were built from Sears kits, but you’d never know it. Original owners of those homes are long gone, and the current owners of them probably have no idea.

There are definite economies to building homes that are “pre-cut” and partially pre-assembled off-site. For one thing, the factory workers can work every day regardless of the weather and even in multiple shifts. They can be more productive in a heated warehouse. There will be more efficient use of materials and more recycling and reuse as well.

Right now, the growing “tiny home” market is doing such construction and delivering modules or even entire homes to work sites, enjoying great economies in doing so. There is no reason that more elements of larger homes couldn’t be built off-site and delivered to construction sites for final assembly.

One example of off-site modular construction utilized in the building of sustainable homes is Structural Insulated Panels or “SIPs,” shown here.  Two sheets of sheathing have 4 to 5 inches of foam insulation between them. SIPs can replace walls built with wood framing and provide superior insulation.

Impresa Modular is a West Virginia company with a great website (www.ImpresaModular.com) describing the many kinds of off-site home construction methodologies they employ and sell.

There is so much innovation happening in home construction, much of which can not only reduce construction costs but can result in better insulated homes.

Here’s a picture of the manufactured home belonging to Butch Roberts of Salida, who sent the comment below:

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.

Accessory Dwelling Units Are Gaining in Popularity

Accessory dwelling units (ADUs) have been around for a long time. Fonzie lived in one (above the Cunningham’s garage), but they fell out of favor with local governments. Recently, local governments have warmed up to ADUs, promulgating zoning regulations encouraging them, especially detached units in a backyard or above a garage.

You may have heard ADUs referred to as backyard bungalows, micro homes, retirement cottages, guest houses, mancaves, she-sheds, or mi casita. They are created for many reasons: independent living for relatives (aging parents, 20- somethings), rental income/investment property, home office, studio, etc. These days it could be quarantine quarters.

Local governments like them as one way to address the pressing issue of affordable housing in a way that is sustainable, is a compliment to the neighborhood, and provides more affordable housing. People hardly realize they are there, and when they do, often want one.

ADUs have been approved by the state of California, where affordable housing is a crisis throughout the state.

The tiny house movement has popularized the idea of radical downsizing and the concept that living in a small space has many positives. ADU’s are not tiny houses, as the term is used today. ADUs are something more. Although small, they are a complete living unit with a full kitchen and bathroom, with a comfortable living area suitable for entertaining. They have a foundation and meet all code requirements. ADUs are more expensive than tiny homes, but they can be worth it.

How much do they cost? Pre-designed manufactured (built off-site) units can be less than $200,000, and even less depending on the characteristics of the site and choices made by the owner.

Would you like to know more? A good resource is at www.AccessoryDwellings.org, created by Kol Peterson. Peterson lives in Portland, Oregon (an early adopter of ADUs), has built many himself, and conducts workshops on all aspects of the process. 

ADU above a garage

Locally, a company called Verdant Living sells manufactured ADUs, not ones that are “stick-built” on-site, so if that works for you, you can email them at bungalow@verdantliving.us for more information.  They can refer you to other companies which build ADUs, whether free-standing, over your garage, or in a walk-out basement.

Personally, I have sold homes which have ADUs. Having a rentable unit can make a home more affordable to many buyers.