Basics of Building an Emergency Shelter

Basics of Building an Emergency Shelter

In the previous article on emergency shelters you assessed your need for a shelter based on climate, physical condition, and materials on hand. Now you need to decide where and how to build your shelter. These three factors will help you decide: Location, Situation, and Orientation.

Location of your emergency shelter

Think of “location” by considering a large piece of your map. In other words, your frame of reference is the whole valley, or possibly the entire mountainside. In deciding where to locate your shelter, you’ll have in mind an area encompassing up to several hundred acres, even a few square miles. If you have seen a water source in the distance, you might travel up to several miles to reach it and build your shelter nearby. Or perhaps your plane crash-landed on a glacier; depending on your environment, your physical condition, and the time of day, you might invest a few hours getting to lower altitude to build your shelter in a better location.

Some general considerations:

  • Low altitude is better. It might be pleasantly cooler at higher altitude, but the weather tends to be unpredictable and even dangerous.
  • Higher elevation is better. I know, I know; this contradicts what I just said. But remember, there are lots of factors to consider. Given your area, on a calm, clear night, cold air will tend to pool in the bottoms. There might be 5-10 degree difference climbing just thirty feet in elevation. I’ve actually experienced it.
  • Level ground is better. Unless it’s raining, and then a gentle slope will prevent your bed from pooling.

Situation of your emergency shelter

When deciding on your shelter’s “situation,” take a more focused view. You’ve traveled a couple of miles to the river side, and now you’re looking around for a good spot; that’s “situating” the shelter. For example, you wouldn’t situate your shelter in the flood plain. If it’s going to be hot, you would situate it in the shade. If there’s a cave nearby, you would definitely consider situating your shelter there.

When considering the shelter’s situation, your frame of reference is going to be something between a few dozen square yards to maybe 10 acres of territory. I know that’s a broad range, but we’re not talking about quantized units here — we’re talking about a continuum affected by many variables. It’s not math. It’s more like biology; you look, you think, you decide, maybe you reconsider, you adapt, you remain flexible.

I’ll give you an example — I was shooting the video demonstrating shelter construction, and I decided to build a lean-to against a fallen tree trunk. But while I was gathering my materials I spotted a better place close by. I changed my mind about where to build the shelter, and it only took about 5 minutes to move the materials. Be flexible. Always look to improve your situation.

Also included in the concept of situation is whether you build your shelter on the ground or elevated above it. Elevating your shelter will take extra energy, but it might be necessary.

Even if you build on the ground, generally you’ll not want to sleep directly on the ground. Make a bed of moss, leaves, grass, or evergreen boughs. Spruce, fir, and cedar are outstanding. They’ll help keep you warm — the earth is a vast heat sink — and also offer some protection from bugs.

Things to look for:

  • Fallen trees. The trunks and even the root balls make a good brace for some poles in making a lean-to. They also make decent reflectors for your fire.
  • Caves. These make awesome shelters.
  • Boulders, cliffs, and rocky overhangs. If you’re looking for the best natural heat reflector, go with stone.
  • Dense tree canopy. Think of a big tree as a roof over your head. Conifers especially tend to shed rain out to the drip line, so building a shelter under one of these puts you way ahead of the game.
  • Snow drifts. Digging into a deep drift is a quick way to make a snow cave, which provides good insulation and protection from the wind. A real life saver.

Orientation of your emergency shelter

To understand how to orient your shelter, just stand where you’ve decided to build it and now decide which way you will face when you sleep. Level ground is nice, but if you’re on a slope, you’ll probably want to sleep with your head uphill. Also, cool air flows downhill after sunset, so you’ll want to be sheltered from that flow — unless it’s hot and the cool air will relieve you. Or maybe it’s cold and you want to sleep against a South-facing rock — unless you’re Down Under, in which case you’ll want to build against a North-facing rock. If a front is moving through, consider the prevailing winds. See how this works?

Keep it simple, keep it small

In the next article we’ll discuss the actual emergency shelter construction, but before you start gathering your materials, set your mind on the overarching purpose of your efforts. The idea is to get you alive and well through the night, so don’t waste time making it perfect, don’t worry too much about being comfortable, and don’t waste time and energy making it too big. Making your emergency shelter too large is a double waste — you waste energy making it big to start with, and then it takes a lot more energy to keep it warm.

And just to drill deep into the science of it, I’ll elaborate. I do realize that there is a relatively small marginal cost to make the shelter a little larger. That is, you can give yourself double the floor space without doubling the amount of materials. But the real problem is heating your space. In the open air, your fire heats the surfaces around it by radiation, not by convection, and radiant energy decreases as the inverse square of the distance. That means that if you double the distance from the fire to your shelter’s back wall (your reflector), the radiant energy striking the wall is not half as strong, but only one-fourth as strong. The smaller the space, the cozier you’ll be.

But even if cold is not a consideration, there’s still no good reason to build the shelter larger, even though the marginal cost is small. Here’s why: the additional size itself gives you no real benefit. You’re not staying there long, so you’re just going to waste the extra space when you leave. In this sense, because the economic benefit of additional size is zero, the marginal cost is actually infinite. In a survival situation, every calorie of spent energy is a calorie you have to recover. It’s not too radical to say that every spent calorie brings you that much closer to death.

All that to say: Keep it simple, keep it small. I’m dead serious.

Also in this series:

Intro to Emergency Shelters

Building an Emergency Shelter with Whatever You Have

~SnoMan

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