So You Want To Live In An Earthen Home – Part 3: Site Selection
In the words of Michael Pollan, “Settling on the site of a new building is a momentous act, at least if you stop to think about it.”1 It can, and should, be a relatively lengthy process, one where a person takes the time and care to observe the site from many angles, and through many lenses, throughout the seasons. Observing the many nuances of the land requires a great deal of patience but it is time well spent. Looking through the various lenses – the practical, the spiritual/energetic, and the historical/ancestral – can make the process extremely fun, while revealing a lot about yourself and what, ultimately, shelter means to you.
The search for practical guidelines on site selection doesn’t come easy. It’s especially difficult to find inspiration on where a house should be placed by looking around us because, frankly, the placement of most homes defies anything resembling common sense. Fossil fuels have allowed us to abandon what is, and always has been, so obvious. In fact, if we look back to the first century B.C. we find a gentleman by the name of Vitruvius, who, in manner of speaking, spelled out the principles of intelligent site selection. He advised that the site of a building be neither too high (where winds can be problematic) nor too low (where drainage becomes an issue), and that the building be laid out on an east-west axis, with the principle exposure to the south where occupants may be warmed by the sun.1 These principles were rediscovered in the 1970s during the Arab oil embargo but the amnesia quickly set back in soon after and we’re back to building as though sunshine will run out before the fossil fuels do.
Now before we launch into more of the specifics, we should rule out two sites that suck many well-meaning people in. The first site we need to rule out is the one that offers the best view. Though it may happen, rarely does the ideal site incorporate the best view. You’ll see why later. The second site that should be ruled out it the one found on the best land. The house can look onto the best land but it should not be placed on it. Taken a step further, the authors of A Pattern Language (Alexander et al. 1977) suggest that a house be placed in the worst area, since placing an intelligently designed home on such a site could, in effect, improve the site. Either way, the advice is the same: place your house on the best land and it’s no longer the best land.
With these general themes in mind, there are two factors that should inform your decision more than the rest. The first is drainage (dealing with water) and the second is orientation and exposure to the sun.
As Vituvius had written, the top of a hill is not ideal (even if the view is spectacular) because the winds will rob the building of heat. Hilltops are also bad for “chi”, as the winds quickly disperse it (more on this later). Low lying areas are to be avoided because you’ll end up with water-related issues, which are a death sentence to any earthen home. Ignoring this logic is precisely why we now see widespread cement use for foundations, as it allows houses to be built in “areas where the subsoil and drainage are not suitable for construction”.2 We now have a situation where standards cater for the worst possible case scenario instead of being site-specific. If we follow Vitruvius’ wise advice though, choosing a flat, well-drained area or one on a gentle slope, we are able to employ less resource intensive foundations like the “rubble trench” instead of those made of solid concrete.
Shifting now to the sun, the advice is simple: make it work for you! Though passive heating and cooling is an involved subject the general goal is to get sunshine into the house when it’s needed (September 23 to March 22 in colder climates) and keep it out when it’s not. According to Daniel Chiras, author of The Solar House, unobstructed access to the sun from 9am to between 2 and 3pm is essential for passive solar heating. A great tool for evaluating the solar potential on the site and how trees or other features may affect the site is the Solar Pathfinder. From a single reading, this simple yet powerful tool can give you accurate data on the solar potential for a particular site over an entire year. It offers a great way to compare two or more potential building sites. It’s also worth keeping in mind that the ideal solar design for most climates is one room deep, oriented on an east-west axis, thereby allowing the sun to reach deep into the interior of each room. You’ll want to see if the site you’re considering will accommodate this. As for keeping the sun out, something you’ll want to do in the summer, it’s really just a matter of adjusting the height of the windows and the roof overhang. The website http://www.susdesign.com/tools.php offers invaluable tools for determining light penetration, overhang design, and more. It’s a tremendous resource and worth spending some time with!
Besides these two main considerations, you’ll want to consider the following: Where is the septic field or composting toilet going? Are you required to install a septic filed and is there a covenant that dictates where it must be placed? Where might you place the compost pile? If the site is inherently breezy, is there an opportunity to use a slope to create an earth-bermed home to block the wind. If two sites are similar, are the soils different? How might this influence your decision? Clay-containing soils are great for cob, light-clay straw, and for plasters. Where is your water coming from? Does the site allow you to harness sun, wind, or water for energy? Does it allow you to expand the home as your family grows? Where will outbuildings go? Where will the gardens go? Obviously there is a lot to consider but keeping these questions in mind will prevent future problems, making the whole process less costly and more enjoyable.
Taking care to observe the “chi”, the earth energy that animates all things, we are further informed about the land and potential building sites. Like water, chi flows in invisible but predictable currents over the land, following the natural and manmade contours of the landscape. It’s blown off hilltops, accumulating in lakes and rivers or, “less propitiously, in swamps (where, hemmed in, it’s apt to turn into sha, the negative energy that is chi’s evil twin.”1 It speeds down steep hills, meandering over gentle contours. Choosing a site that invites chi, causing it to enter our living spaces and linger, brings good energy and who doesn’t want lots of good, positive energy.
To borrow on another theme found in Michael Pollan’s A Place of My Own, we may approach a site from a somewhat primordial perspective asking, “What exactly makes us, we humans, feel comfortable in a place.” Homo sapiens, having spent 99 per cent of their time on earth as hunter-gathers, should have, according to Pollan, “acquired a predilection for landscapes that offer a high degree of… “prospect” and “refuge”: places that offer good views - of potential supplies of food as well as sources of danger - without compromising a sense of shelter. It follows that we feel most comfortable when we can see without being seen -- an interesting thing to ponder when trying to find that “perfect” place to site a home.
Like finding the land in the first place, selecting a site for your home requires a great deal of observation and deliberation. This process offers the opportunity to connect with a place, deeply, setting in place the chance to reawaken and sharpen the senses. T he observation potential is endless but know that the advice of your senses and intuition is often your most reliable guide. It also provides a great space for building a little temporary shelter, preferably using the technique you plan on applying to your home. Work out the kinks early and enjoy the experience. It’s a fun journey!
1 Pollan, Michael. A Place of My Own. (London: Penguin Books Ltd, 1997)
2 Weismann, Adam & Bryce, Katy. Building with Cob. (UK: Green Books, 2006)
3 Eitel, Ernest J. Feng-Shui. (1873).
4 Kahn, Lloyd. Shelter. (Shelter Publications, 1973).