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Bivy Sack or Tent | How Do You Decide?

There are many decisions to be made when preparing for a solo camping experience, and choosing the right shelter for your needs is increasingly tricky. How rustic and “with nature” do you want to be, or do you prefer “personal space”? Have you considered the environment, including climate, bugs, people, and the landscape? All these factors and more will influence your decision.

Deciding between a bivy sack or a tent depends on the goals of your trip. Bivy sacks weigh 10-16 oz, making them best suited for those who like keeping their pack light to cover more territory. A lightweight tent weighs 1-2 lbs and provides better protection from weather and nature while offering more space and privacy.

There are trade-offs whether you opt for a bivy sack or a tent during an outdoor excursion. Technological improvements have muddled the lines between the two classes, and which option was best for one trip may not apply to another.

A bivy sack next to a small tent with a woman sitting outside

What Is a Bivy Sack?

Chances are you know what a tent is, but if you are new to solo camping, then a bivy sack may be new terminology. The word bivy is shorthand for bivouac, which means “temporary shelter without cover.”

They were designed with climbers in mind who needed something light to protect themselves from precipitation and to offer some increased warmth (about 10F). With this premise in mind, early “bivys” were simply a waterproof nylon cover for your sleeping bag. Issues were quickly raised, though.

Bivy sacks aren’t fully enclosed, so you can’t protect yourself from flying insects or those on the ground. A major issue is ventilation, as your body heat produces vapor, and this tends to just condense in a bivy sack.

Bivy Redesigns – Bridging the Gap to a Tent

To circumvent the problems with the “slipcover” type sacks, new materials and the development of the bivy shelter model were introduced. Typically, modern bivy sacks are constructed with two distinct layers:

  1. The bottom/ground layer is made from a durable grade of nylon that has been coated in urethane. The fabric is identical to the ground layer in most tents which means you do not need an additional groundsheet in your pack.
  2. The top/exposed layer is made from ripstop nylon, which is a woven, breathable material resistant to tearing and ripping.

To make it waterproof, the nylon is treated with a breathable laminate, e.g., Gore-Tex®. This allows the vapor to escape through the fabric and away from your body, avoiding condensation. However, condensation will still happen from time to time, and this means your bivy will need to be dried.

Bivy Shelters

While it does add extra weight, bivy sacks have been modified into bivy shelters. These models are fully enclosed and have a raised section above your head. Frequently, these sections are mesh with an optional weatherproof flap.

The weight stems from the poles or hoop required to lift the fabric from your face. This design allows you to still feel like you’re fully sleeping outdoors without fear of being bitten by bugs as you sleep.

Additionally, traditional bivy sacks can let moisture in as they are open at the face. Either you get wet or try and pull the sack tightly around your face leaving only enough space to breathe. This created claustrophobia for many users, and the bivy shelter somewhat eliminates this issue.

Location: Can You Even Put up a Tent?

Depending on your adventure, you may find yourself sleeping on a mountain’s edge or on terrain that has limited flat space. In these instances, there is nowhere to pitch your tent. Likewise, if you’re exploring rock caves or snow caves, then a bivy sack might be your only option for weatherproofing your sleeping bag due to the lack of vertical space.

If you’re sleeping in urban areas, e.g., while on a long bike ride, then legally, you will be able to sleep in a bivy. Laws exist that prevent tents from being pitched in these areas to discourage the practice in the homeless population.

Need More Space? Choose a Tent

Many solo campers opt for a tent during their trip to have more space. This is a growing trend as the cost of ultralight tents is decreasing.

Unlike a bivy, you can sit in your tent to read, bathe, or change clothing. Provided you are not using a flame, you can eat your meals inside a tent, too, knowing the circulating bugs won’t have access to it.

Tents are also considerably easier to get in and out of as they have a door. The space offered by a tent also reduces the feeling of claustrophobia considerably as you can move in the increased headspace. A bivy sack can feel a bit like sleeping in a body bag.

Combined, these benefits can make the camping experience far more enjoyable and will likely result in a better night’s sleep. If you’re going on a multi-day camping trip, then these benefits should not be ignored.

Woman Camping In Tent Mountain View

Security of a Tent

Humans need to feel safe to rest effectively. While some may never feel secure in a tent, it is considered safer than a bivy sack. There are many elements to this increased safety, including naturally occurring and man-made ones.

A tent is far better at protecting you from wildlife than a bivy sack – especially a traditional one where your face is open to the air. If you are camping in bear country, you may be worried about them attacking you.

Although the data isn’t conclusive, it is generally considered that a tent will protect you better from bears. It is believed the size of the structure is offputting. However, bear attacks are extremely rare if the bear isn’t provoked.

Tents irrefutably do protect you better from smaller creatures, though. While sleeping in your bivy, you can feel mice, scorpions, and even snakes traverse your body. Your open face makes you far more vulnerable to being bitten or waking with companions in your sack.

Conversely, a tent is harder to penetrate, and you can sleep away from the edges, so you don’t feel nature rushing past. Even a squirrel foraging nearby can be frighting in a bivy sack.

You have greater protection from the weather too. Riding out a storm in a bivy sack or shelter can be a harrowing experience. In a tent, you will remain dry in the wildest of storms. Tents can also be rated for four seasons, making them appropriate during snowfall and high winds.

The security advantages of a tent rise exponentially when other humans are around. You can have all of your belongings inside your tent with you. This significantly reduces the chance of theft as the potential criminal can’t see if you are sleeping or not or if you are alone.

In a bivy, you are exposed and can be watched until the right opportunity presents itself. This is especially valuable if you plan for your camping spot to be a base camp for a few days. This way, you do not need to take everything with you when you go for a bike ride or a hike and can feel secure that your items are safe. This is not a luxury provided to bivy sack users.

Other Considerations

1. Time

Tents take longer to set up and take down than bivys. This may be incredibly important in the rain when in a minute, you could be safe inside your bivy sack.

2. Backpack Space

A bivy will typically take up a liter of space in your backpack, and a tent will minimally be twice that.

3. Cost

A decent tent will cost you upwards of $200, whereas a bivy sack of equal quality will cost half that.

4. Openness

Many tents now have rain covers (flys), meaning you can sleep with only mesh as your roof. Therefore, in both bivvies and tents, you can feel as though you are sleeping under the stars.

5. People

Here, we have been concerned with a solo trip, but if you are with a companion, a tent is a better option as a lightweight tent will weigh less than two bivy sacks combined. You can also share the tent’s weight during your journey.

Bottom Line

Ultimately, once you balance all of these factors, it should be clear which shelter is best for you on your trip.

Personally, I like elements of both bivy sacks and tents. Therefore, I use a hybrid which I call a “bivy tent.” Here is a really good one found on Amazon. It’s lightweight, easy to set up, waterproof, and comes with a built-in mosquito net.

Related Questions

What other minimalist shelters are available? Many lightweight campers chose to sleep under a tarp, which will protect them from the rain and sun only. In forested areas, hammock tents have become popular as they are easy to set up and are bug and weatherproof. Some experienced campers forgo additional shelter altogether and simply chose to sleep in their sleeping bags on a groundsheet.

What is ultralight backpacking? Ultralight refers to keeping your total gear below 10 lbs. To achieve this, everything in your pack must be produced from the lightest materials, and only the essentials should be considered. The biggest weight savings will be from the big three: shelter, sleeping bag, and the carrying system itself.

For more, check out 10 Ways to Build a Shelter out of Natural Resources.