We need housing. The U.S. is underbuilt by 5.5 million housing units (at least). And yet, we also have a global imperative to reduce emissions into the atmosphere, especially carbon emissions. Is there any way to create this housing without adding to carbon emissions? Can we get to “net zero” housing?

Any answer dealing with carbon emissions is necessarily complicated. There is carbon emission in the creation of building materials, in the actual construction, in the actual living in the house over its lifespan, and maybe even in the ultimate destruction of the home. An honest assessment has to account for the emission effects at each stage in its lifecycle.

If we build a house to last for hundreds of years, we can reasonably argue to ignore the ultimate destruction and repurposing of the house. And there are many houses that have stood for hundreds of years, so for the moment let’s just forget about that factor. How do we reduce emissions enough in the creation of building materials, the construction of the home, and the use of energy while living in the home to get to net zero?

Most of the building materials used in a home are neither particularly sustainable nor carbon friendly. From lumber that takes 40 years to mature to asphalt shingles and fiberglass insulation, traditional building materials were not created with sustainability or resource management in mind.

However, there are alternatives for these building materials that are available today and are much better for the environment. One of the keys is to find ways to pull carbon out of the atmosphere, not just reduce emissions into the atmosphere. A promising building material is the hemp plant. Hemp can be used in insulation, building panels, hempcrete, and even hemp-based bioplastics. Hemp sequesters carbon from the atmosphere better than just about any other plant. And if carbon friendly agricultural practices are used such as no-till farming, and no pesticides or herbicides, hemp products may actually be carbon negative (less than net zero) even when including the emissions created during processing.

Hemp can replace less sustainable building materials like lumber, steel, asphalt, and fiberglass. And when hemp becomes part of a house, the carbon it sequestered when it was growing in the field is permanently sequestered as part of a house. Using hemp can make it so that the materials of a house are effectively carbon negative.

Building a house also has implications for carbon emissions. The two best ways to reduce those emissions may be to cut the time necessary to build a house and to cut the material waste that is created when building. Both of these factors can be addressed by advanced construction techniques. Modular and panelized construction can substantially reduce the time necessary and some of the waste. But 3D printing of homes and components essentially eliminates waste and drastically cuts the time (from months to days) even beyond that of modular construction.

Since 3D printing uses some form of concrete or hempcrete it also can make walls and roofs that are better insulated than traditional construction. Using concrete that is of higher strength (10,000 PSI) allows a builder to forego rebar. (If rebar is still necessary, using a basalt version instead of iron can prevent severe damage from moisture.) 3D printed houses are fire resistant, moisture resistant, and can be made to withstand both 8.0 Richter scale earthquakes and 250 mph winds from severe weather events. These features ensure longevity for the home by preventing the most common reasons a house is destroyed.

The substantially higher insulation values also reduce the carbon footprint while someone lives there. Better insulated houses reduce the energy requirements for heating and cooling, the main impact of a home on the environment during its useful life. When this is combined with energy efficient appliances, intelligent design, and automation that manages the use of HVAC systems more effectively, the lifetime of the home can also be net zero.

We can, in addition, use solar power cells, the new power walls, or solar roof shingles to further reduce the reliance on non-renewable resources. But it is important to understand the carbon footprint of creating those capabilities to ensure that the reduced energy cost is not overbalanced by the energy used in creating the solar cells. For example, the mining of rare earths – necessary for the creation of solar cells – is an environmental horror. And they are not renewable resources (hint: they are called “rare” earths). We have to understand the true carbon footprint of solar over its lifetime to know whether it helps us get to net zero or not.

Overall, we can expect that while living in the home there will be some amount of carbon emission – since we don’t have a good opportunity to sequester carbon during this stage of the home’s lifecycle. The key to net zero, then, is to be carbon negative enough in the creation of building materials and in the building of the house that the low emissions during occupancy bring us up to zero over a relatively long period of time.

Is net zero possible? With the use of hemp and 3D printing along with modular and panelized construction, it just might be.


Steve Streetman is a real estate consultant specializing in deal structuring and the use of cryptocurrency. Look for his book, “Cryptocurrency and Real Estate: how to profit as Bitcoin and Blockchain transform real estate investing” available now on Amazon in paperback and ebook formats. You can also find out more at https://CryptoREBook.com.


  • Steve Streetman

    Steve Streetman is a data scientist, systems engineer, commercial real estate investor and exchangor, and an avid cryptocurrency investor. His background in cryptography and long career in systems integration and risk assessment combined with real estate investment expertise makes him the perfect person to combine cryptocurrency and real estate. Steve has written numerous articles for real estate investment magazines and regularly presents at his local real estate investment association. He teaches the commercial investing course at the DCREIA. Steve is a member of the National Association of Realtors (NAR) and the National Council of Exchangors (NCE). Steve lives in Maryland, USA, with his wife, Christy and has two children, Michael and Holly. When not constructing investment deals or applying advanced algorithms to important problems, Steve enjoys sailing, tennis, music, and theater.

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