The 1,000-year, carbon-absorbing house, and how you could have one – free

It is possible with current technology to build houses that last essentially forever, barring direct hits from meteors or missiles. In fact, it is possible to do so with 1,000-year-old technology, as we can plainly see from examples still standing. These same houses can be carbon-neutral or even be net-carbon-negative, including providing all or most of the their own heat and hot water. These houses can be built for less than current construction.

Sound impossible? It’s not. It is very possible. There are working examples of net-zero homes that will last forever. Getting one free is the real trick, but it is can be done.

The 1,000-year House

Earth bricks, adobe, cob, stone, and brick – all will last essentially forever with decent maintenance. We know this because there are examples still standing, from the adobe structures of the native Americans to European palaces.

In the past, these types of buildings have been quite labour-intensive, but there is a new technology that automates some of the process of making bricks, cuts the energy required to make them, and allows rapid construction of homes with excellent thermal mass, ideal for passive solar heating. The technology is called Compressed Earth Blocks (CEB), and allows manufacturing all the interior and exterior walls from subsoil. That’s the stuff see offered for free at building sites – “Free Clean Fill” – after someone excavates the foundation and basement and now has a mound of dirt to get rid of.

Why not build the house out of dirt? Look at the photos in this article; all are made from  CEBs or adobe and then plastered. They look like a regular house with thicker walls. These thicker walls – typically ~16-24″ – not only make it easy to build in window seats, they add thermal mass to keep the house temperature constant, are fireproof, insect-proof, and are highly resistant to hurricanes and extreme weather. They are also bullet-proof, a potential plus should civil society take a turn for the worse when the oil runs out.

The Carbon-neutral House

Great Britain and France have mandated net-zero carbon homes by 2016 and 2020, respectively. A net-zero energy home has “zero net energy consumption and zero carbon emissions annually.” That means that sometimes the house and its occupants are drawing energy from the grid and sometimes they are supplying energy, and the net is zero over the course of a year. Examples of these types of houses already exist in developed countries.

In addition, by building out of local materials, the carbon released to build the house is greatly reduced. Once carbon-absorbing cements are commercially available, then compressed earth blocks with this cement added will draw down carbon from the atmosphere. Add a green roof and even more is absorbed by the plants living on the roof.

Cutting Bills to the Bone

So now you have a house that emits no carbon for heating, hot water, lighting, and so on. That’s a significant monthly saving – no energy bill, and possibly even a monthly cheque! But bills can be cut even more: Use composting toilets rather than flush versions, and reuse gray water on site, and now you eliminate the need for a sewer line. That cuts taxes.

Composting toilets have come a long way from the bucket-and-chuck-it system.  (That said, if you are seriously concerned about a breakdown of civil services in the post-peak-oil world, the bucket system will be by far the most reliable.) Modern versions don’t smell – in fact, a small exhaust fan can be placed to draw air from the toilet itself so that only the most determined of disagreeable odours escapes.

That leaves a water supply line, cable, telephone, internet service, and other utilities. Of course your water bill will be lower without flush toilets, which typically consume  about 25% of the total water used.

The 1,000-year, Carbon-neutral, FREE House

Ah, the catch. It’s free only in the sense that you don’t have to put any money out of pocket, but you do have to provide some labour. Here’s how: If you have the skills and time to build such a house, find someone with money willing to pay for the land and materials for two houses. You provide the labour to build two houses, and voila, each of you gets a  house and yours at least is free-and-clear except for the land, which you get free another way.

This works because the cost of building a home is typically about 50/50 materials and labour, plus the lot. I’ll come back to getting a free lot in a moment. Both parties get a fair deal; the money-person gets a house for the same or less than he would have paid anyway, and the builder gets a house for the cost of his labour. Who has this kind of money? Most doctors and lawyers have the cash to pay for two houses this way, as do many retired people. Granted, a lot of labour is required to build two houses.

Ideally, you find a group of people willing to put up the money and a group of people with house-building skills. That way risk is divided and the people doing the building don’t need to know everything about making a house, from foundation to wiring to roofing. They can specialise and work as a team, which reduces the amount of labour required.

How much time do you have to put in? Compressed earth block houses go up very quickly. My radio partner witnessed all the exterior and interior walls of a conventional-looking but CEB bungalow in New Mexico go up in one week. Avi Friedman, co-designer of the Grow Home, cut the cost of building townhouses in half simply by designing smart. Part of this cost saving was a reduction in materials, part a reduction in labour. Their goal, as he described the Grow Home in an interview with us, was to make the Honda Civic of housing: attractive, high-quality homes that people would be proud to own. Homeowner surveys done after people had been living in them for a couple of years showed a very high level of satisfaction. Using CEBs for Grow Homes would cut the cost even further.

Another up-front cost-cutter was to leave some areas of the house unfinished, typically the basement and a spare room. The homeowner could finish them later when time and finances permitted.

In Victoria, Canada, the cost of construction is about $200 per square foot for good quality construction. The price goes up for marble countertops, and down for plain and simple. Sticking with the ‘good quality’ level, let’s turn it into a Grow Home and thus cut the cost to $100 per square foot, or $150,000 per 1,500 square foot townhome. The money person provides $300,000 for two houses, and you provide labour to build two houses.

You’re probably going to be have to work about one year full-time building the houses. Can’t afford to do that? Find an additional person who has money for a house. Now you have two people putting up $450,000 total for three houses, plus another $45,000 to pay you a wage for 1.5 years. The end result is three townhouses that cost $165,000 each in materials to build. Land, of course, is extra. For comparison, a 1992 townhouse of similar size and moderate quality just sold in my complex for $424,000. I imagine the cost of construction and land would be much lower in, say Detroit.

That Free Land

At one time, Michigan was offering $25,000 to people who moved there and took over a derelict home, but I can no longer find a reference to that program. That said, there are lots of houses in Detroit, Flint, and other Rust Belt cities that are going for under $5,000, even many under $1,000. As you’re going to demolish the house, the cheaper the better. You may even be able to salvage some items for your new place.

At those prices, even without the $25,000 bonus, the money guys can pay for the land; it has become a minuscule part of the total cost.

An Income is Still Needed

So you get something as close to free as possible. How do you live? You have no mortgage, property taxes are low, but still have to buy groceries and such. If a walkable community was built near a transit line, you could also forgo a car.  Now you have no mortgage, no car payment or car expenses, and low property taxes. How much would you need in that situation?

Detroit could be rebuilt in this way, providing secure jobs and mortgage-free homes for many thousands of people.. I’ll describe that in Part II, tomorrow.

UPDATE: Feb. 6, 2009 – See article A 500-year, Net-zero, Cob Solar House for Half the Cost of Conventional Construction for an example of what could be done. I’ve been through the house twice (it’s close to me and I know the owner-builders).

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Building with Earth and Straw Resources

There are many great books available that describe how to build a durable, beautiful, and energy-efficient house. I would also recommend reading Ann and Gord Baird’s eco-journey. There are friends who built a cob house in Victoria, BC, and they did it right. Check out the Natural Building link for a thorough description of everything from costs to dealing with building inspectors.

The books below are top-rated and cover, in order from left-to-right: Building with cob (uncompressed earth mixed with straw), earthbags (just like stacking sandbags), earth in general (a more technical book), and straw bales. All systems are relatively easy and cheaper than stick-built – and much less than concrete block.