Bivy Sack Vs Tent: Pros and Cons and Which is Best?

These days, the trend in camping shelters is toward minimalism. Everyone is going ultralight. One great way to cut weight and bulk from your pack is to switch from a tent to a bivy sack. A bivy is a weatherproof cover that you put your sleeping bag inside. This guide outlines the pros and cons of using a bivy vs tent to help you decide which is best for your next camping trip. I’ll cover weight, packed size, weatherproofing, comfort, and more.

Generally, bivy sacks are lighter, more compact, easier to set up, cheaper, and more durable. Tents are more spacious, more protected from the elements, more comfortable, and they deal with condensation better.

Bivy sacks are better for ultralight hikers, minimalists, mountaineers, those traveling fast, and emergency use. Tents are better for families, longer trips, camping in inclement weather, buggy areas, and those who value comfort and privacy.

I grew up using tents but began experimenting with bivy sacks a couple of years ago to cut down my base weight when I went ultralight. So far, I have spent around 60 nights in bivy sacks. In this guide, I’ll share my experience.

What is a Bivy Sack?

A bivy sack or bivouac sack is a liner that you put over your sleeping bag to protect you from precipitation, insects, and dirt. They were originally used by climbers who needed a lightweight and compact shelter to use for weather protection during multi-day ascents. 

These days, bivies are a popular ultralight shelter option for minimalist bicycle tourists, bikepackers, hikers, and travelers. Militaries around the world use them as well. Bivies can be used as a standalone shelter or paired with a tarp for extra protection. Most models weigh just 1-2 lbs (about 454-907 grams).

A wide variety of bivy sack designs exist for camping in different conditions. You can choose between waterproof and non-waterproof breathable options. Some bivies zip completely closed to keep insects and water out. Some bivies use a small pole to keep the material off of your face as you sleep. These are sometimes called bivy tents. Basic bivies and emergency bivies simply leave the face open. There are also bug bivies with a mesh top and waterproof floor.

Most bivy sacks are made of a breathable material that is waterproof or water-resistant. Gore-Tex or Argon fabric is common. Lower end bivies are made of nylon coated with urethane. High-end ultralight bivies are often made of Dyneema (cuben fiber). A bivy sack is sometimes called a bivi bag or bivvy sack.

Bivy Sack Pros

• Bivy sacks are lightweight- The lightest bivies weigh just over 4 ounces (113 grams). They are made of a modern lightweight material called Dyneema or cuben fiber. The heaviest Gore-Tex military issue bivies weigh about 2 pounds (907 grams). The average bivy weighs around 1 pound (454 grams). This is around half the weight of an ultralight one-person tent. This is a significant weight savings. Carrying less weight allows you to travel faster. Keep in mind that you may also need to carry a tarp with your bivy to protect you from the rain if your bivy isn’t waterproof. This adds a bit of weight.
• Bivies are compact– A bivy takes up less than a liter of space in your pack. That’s about the size of a big burrito. It is the ultimate minimalist shelter. This is because no ground sheet, poles, or stakes are required. Bivies also contain less material.
• More campsite options- Bivy sacks have a small footprint. You can set up camp pretty much anywhere you can lay down. This is great in areas with rugged terrain or dense vegetation. Sometimes it’s difficult to find a large enough piece of flat ground to pitch a tent. You could camp on a rock ledge, between bushes, in a snow cave, etc.
• Wild camping with a bivy is much easier than a tent- Bivies don’t stick up above the ground like a tent does. The low profile helps you stay hidden. This makes finding a campsite much easier. For example, under a tree, behind a bush, under a vehicle, or behind a wall are all possible campsites with a bivy. This opens up the possibility for urban camping if you have the nerve for it.
• Setting up camp and packing up in the morning is faster- It doesn’t take as much time to set up a bivy. Just unpack your bivy, shove in your pad and sleeping bag, and you’re ready for bed. Packing up the next day is faster as well. Because you don’t have to mess with poles or stakes, you can just stuff everything in a bag. Some campers simply roll up their bivy, sleeping bag, and sleeping pad all in one bundle and hit the road. The next night, they can just unroll it and be ready for bed in just a matter of seconds. This saves a few minutes and a bit of hassle every day.
• More durable- There are no poles that can bend or break. Bivy floors are made out of thicker, more robust material so groundsheets are not required. Many bivies don’t even have zippers that can jam or break. The worst that can happen to a bivy is a tear which can be repaired with patches or a sewing kit. You can stuff and compress most bivies without any issues. 
• Bivy sacks are cheaper- You can get a high-quality custom bivy for around $100. You can buy a basic bivy for less than half that. Any tent in that price range will either be very heavy and bulky or low quality. Decent lightweight tents start around $200.
• Bivies perform well in high winds- Because of the low profile, the wind blows right over you in a bivy. After all, the highest point is just a foot or so off the ground. You can easily camp in heavy windy conditions that would destroy most tents.
• Protection from drafts- Bivy sacks act like wind shirts for your sleeping bag. They keep the drafts out when you turn over in your sleeping bag or quilt.
• Great for people who toss and turn in their sleep- If you tend to roll off of your sleeping mat while you sleep, bivy sack help you stay in place. After all, there really isn’t anywhere you can go. 
• Bivy sacks don’t require you to use a groundsheet- Most bivies are made with a durable bottom which will not tear or puncture easily. A groundsheet may extend the life of your bivy but is not required as it is with most tents. This saves also saves weight.
• Bivies keep you warmer- Bivies add 5-10 degrees of warmth to a sleeping bag. The reason is that there is less empty space inside that your body needs to heat up. There is also less surface area for heat to escape from. Bivy sacks provide some level of insulation. For this reason, bivy sacks are a great choice for winter camping. This can also help you lighten your pack because you can get away with a lighter sleeping bag.
• Visibility is better- If someone or something is approaching you, you can easily sit up and look around. While sleeping in my tent, I have heard strange noises or footsteps on a few occasions. In order to see what or who was there, I’d have to get up and go outside.
• Bivies make your sleep system more modular- With a bivy and tarp, you are ready for any conditions. If there is no rain, you don’t need to bother setting up the tarp. When there are no bugs, you can just cowboy camp without the bivy. If it’s hot and buggy, you can do without your sleeping bag and just sleep inside the bivy.
• You sleep under the stars- When you sleep in your bivy, you get to enjoy the spectacular night sky every night. One of the best nights of my life was the first time I saw the milky way while camping in the Namib Desert.
• You can fly with your bivy sack in your carry-on bag- Most airlines don’t allow tent poles or stakes in the cabin for security reasons. Because most bivy sacks don’t use poles or stakes you can pack them in your carry-on. This is great for those who fly to their hiking destination. You save money on checked bag fees and you save time because you don’t have to wait for your bag at the baggage claim. 
• In a bivy, you are more connected to the environment- You are basically sleeping in nature. In a tent, you are in a small room outside.
• If you’re male, you can urinate without getting up- You can just unzip your sleeping bag and bivy and go. No more getting up in the cold to take a leak. You’ll want to make sure it flows downhill and not back into you and your bivy, of course.
• Bivy camping feels more adventurous- Because you’re more exposed in a bivy, it just feels like an adventure. It’s like the cowboys used to camp in the wild west.
• You can use a bivy as an emergency shelter- If you’re not sure whether or not you’ll have to camp, you can carry an emergency bivy just in case. These can keep you warm and dry in an emergency situation.

Bivy Sack Cons

• Condensation- This is the biggest drawback to bivy sacks. You will experience condensation in pretty much all bivies. How bad it gets depends on a number of factors including the material your bivy is made of, the weather conditions, the temperature, and your sleep habits. Moisture from the environment and your breath builds up inside and condenses on the inside of the bivy. This happens because the waterproof breathable materials that bivy sacks are made of don’t breathe as well as the mesh that most tents are made of. Because your sleeping bag touches the inside of the bivy, it tends to get wet. In the worst conditions, you could wake up in a soggy sleeping bag. This condensation issue can be dangerous because down sleeping bags lose their warmth when wet. If you’re unable to dry your bivy and sleeping bag before the next night, you could be in trouble. To reduce condensation, you want to have as much airflow as possible in the bivy. Tie a guy line from the top of your bivy to a tree or trekking pole to help hold the bivy open. Leave the hood unzipped so moisture can vent. Breathe fresh air through the mesh and not into your bivy. 
• There is no space inside the bivy to do anything- You can’t change your clothes, organize gear, look at your map, or do anything other than just lay there. Some larger bivies may have enough room to read a book in. If you get stuck in the rain for a few days, just laying there gets old pretty fast.
• Not a stand-alone shelter- Most bivy sacks are water-resistant, not waterproof. To protect yourself from the rain, you’ll want to pair your bivy sack with a light tarp. This isn’t always the case. There are waterproof bivy sacks that are made to be used without a tarp. Some can handle light rain.
• You can’t bring your gear inside- Most bivies don’t have space for your pack or boots inside. You might have space for small items like your phone, camera, or a small bag but nothing more. Even with a one-man tent, you have space for a decent amount of gear as well as a large vestibule for your boots and jacket. For this reason, you’ll want to have a tarp to keep the rain off of your gear.
• You have to sleep alone- Bivies are made for one person. Camping in a bivy is a solitary experience. You can’t sleep next to your dog or significant other in a bivy. 
• No privacy- When camping with other people, you have no privacy in a bivy. You are out in the open at all times. It’s nice to have some privacy for certain things like changing clothes, reading, taking a nap, organizing gear, etc. 
• Staying in campgrounds can be awkward- This entirely depends on the campground. I don’t know about you, but I would feel a bit awkward about rolling up to a campground and sleeping in my bivy amongst a bunch of RV campers. Maybe if I set up a tarp I would feel a bit less exposed. In my research for this article, I have read a couple of stories of people being turned away from campgrounds because they didn’t have a tent. It sounds ridiculous, but I believe it has happened.
• Bivy sacks are claustrophobic- If you have problems with small spaces, sleeping in a bivy may be difficult. This depends on the style of bivy you have. Some zip up all the way like a body bag. As a person with claustrophobia, I would have problems sleeping like this. Some bivies have a big mesh face hole. This is less claustrophobic. Some bivies just leave the face open. In this case, it’s no different than being inside a sleeping bag.
• Getting in and out is a hassle- This depends on the design of the bivy, but in general, climbing in and out can get old. Particularly if the opening is small. Some bivies have long zippers going down the side to make getting out easier.
• You have to dry out your bivy and sleeping bag often- No matter what you do, condensation will wet your sleeping bag occasionally. When this happens, you have to take time to set the bag in the sun or by the fire to dry it out. A wet down bag won’t keep you warm. Synthetic bags can be used when damp but it’s not ideal.
• Bivies are miserable in the rain- You have to leave your bivy open at least slightly so you can breathe. This opening allows rain to come in during a heavy storm. Even if you set up a tarp over your bivy, water can still splash in during heavy rain. For this reason, bivy sacks aren’t ideal as a primary shelter. They are better for use in good weather.
• You have to deal with more critters- Slugs, ticks, ants, and mosquitoes can get to you in the night if your bivy has an open face. This isn’t really an issue with bivies sealed with a mosquito net though. Sometimes mice may walk over you in the night. Animals may approach to sniff or check you out. This could get kind of creepy.
• There is no vestibule- If you want to keep your pack and boots dry during the night, you’ll need to set up a tarp.
• Bivies are less secure- People can tell that you’re inside from a distance. They see you just laying there. If someone sees a tent, they can’t tell if it’s occupied or not. They can’t see who you are or what you’re doing. They may be less likely to approach or try to rob you. This could come in handy when wild camping where people could potentially find you.
• Bugs can bite you in your bivy- This depends on the type of bivy. Some have nothing protecting your face so you are partially exposed. In this case, mosquitoes and other bugs can bite you in your sleep. Some bivies have mesh to protect your face. For this to be effective, it must be propped away from your face with rope or a pole. Mosquitoes can bite through the mesh if it is laying on your face.
• There may be a slight risk of suffocation- While researching this article, I read a couple of posts warning not to completely zip the bivy closed because you could run out of oxygen and die. I didn’t find any credible evidence to support this claim. However, it is something to keep in mind. I’m not a doctor, but it seems possible under extreme conditions. Normally, if you run low on oxygen, you would naturally wake up gasping for breath. The body naturally knows when carbon dioxide levels are getting too high. If you fell asleep very drunk or in extremely cold weather, you could potentially suffocate. Whatever the case, it is a good idea to leave your bivy partially unzipped so fresh air comes in, just in case.
• Bivies look like body bags- The first time I saw a bivy, I laughed and thought to my self, who would want to sleep in that body bag? After learning more about them, I understood the appeal a bit more. 

Tent Pros

• Tents give you enough space to move around- Even in a one-man tent, you have room to move around, change your clothes, sit up, read, write, study your map, organize your gear, clean, etc. This is particularly nice if you get caught in the rain for a few days. You can easily hang out in your tent and keep yourself occupied. It’s your own little room.
• You can bring your gear inside- Tents have plenty of space to bring electronics and valuable gear inside with you. This way, they are protected from rain and theft.
• Tents have a vestibule for storage- Here, you can store bulkier gear such as a backpack, boots, and jackets to keep them out of the rain.
• Condensation is less of a problem- Because tents are more spacious, they have better airflow. Condensation is less of a problem. Most mornings when I wake up in my tent, there is some condensation on the walls and ceiling but my sleeping bag stays perfectly dry because it doesn’t touch the walls. 
• Tents offer privacy- You have your own little room where you can be by yourself, even in a crowded campground. You can change clothes and even wash up a bit inside your tent. When I travel, I often stay in dorm rooms in hostels where there is no privacy. I enjoy sleeping in my tent once in a while because it gives me some alone time. Check out my article for more reasons I always travel with a tent.
• You can sleep next to family and friends- Tent camping doesn’t have to be solitary. Tents come in all sizes. You can sleep next to your friend, your dog, or even your whole family in a tent.
• Tents are more secure- A person who is up to no good will be less likely to approach you in your tent. They can’t see who is inside or what you are up to. If you are in a bivy, they can see from 100 yards away that you are just laying there.
• Theft is less likely- At campgrounds, you can leave your belongings zipped up in your tent. You can even put a lock on the zippers to deter thieves. A criminal will be less likely to rob you because they don’t know if you’re inside or not. You can leave your bivy sitting around with your stuff inside, but it would be easier for a thief to take something.
• Tents offer better rain protection- A good tent can keep you dry even in the heaviest of rainstorms. The reason is that the rainfly is completely waterproof. You’ll get better sleep when you stay dry.
• Tents are easier to get in and out of- Most tents have a large door for easy access. You can enter head or feet first. Bivies have a small hole that you must enter feet first.
• A modern tent are almost as light as bivies- The lightest tents weigh less than 2 pounds. This is comparable to most mid-range bivy and tarp combos. You may be carrying a few ounces more but it is very close. I have the Big Agnes Fly Creek HV UL 1 which can pack down to a trail weight of 1 pound 11 ounces. Read my full review here.
• Tents offer better protection from critters- You don’t have to worry about mosquitos, mice, slugs, ticks, or anything else once you’re zipped inside your tent. I can get a more comfortable night of sleep knowing that a mouse won’t crawl into my sleeping bag in the middle of the night.
• Tents look cooler- Your camp looks more like a camp if it has a tent. A tiny bivy sack on the ground doesn’t look much like a camp.

Tent Cons

• Tents are heavy- An average one-man tent weighs 3-5 pounds (1360-2268 grams). Ultralight options weigh about 1.5-2 pounds (680-907 grams). An average bivy weighs around 2 pounds (907 grams). Ultralight bivy sacks weigh around .5 pounds (227 grams). Additionally, you might need a sleeping bag with a 5-10° F higher warmth rating when you use a tent because tents aren’t as warm. This adds a few ounces as well. The extra weight of a heavier tent slows you down.
• Tents take more space to pack- You need a groundsheet, poles, and tent pegs. This takes up an extra liter or two in your pack. Bivy sacks take up about 1 liter of space. That’s about the size of a Nalgene bottle. 
• Tents are more expensive- Decent backpacking tents start around $200. Cheaper options are available but they will be heavy, bulky, or of low quality. You can buy a high-quality bivy for around $100. You can purchase a basic bivy sack for around $50.
• Tents are fragile- With a tent, you have more pieces and parts to worry about breaking. The poles can bend or break if you’re not careful. The floor can get holes if you don’t use a groundsheet. zippers can jam or break. Bivies are a bit tougher.
• Wild camping is more difficult- Tents are much taller and larger than bivies. This makes them more difficult to hide. You also need a larger spot to pitch your tent. You can’t just sleep in a ditch or between some bushes like you can in a bivy. On some occasions, I have spent over an hour searching for a suitable spot to pitch my tent when wild camping.
• Setting up and taking down a tent takes longer- You have to put the poles together, construct the tent, mess with pounding stakes and tightening guy lines. A bivy can be ready in less than a minute if you’re quick. This comes in handy when it’s raining or dark out. 
• Tents are colder- Because of all of the extra space in your tent, heat more easily escapes. You need a warmer sleeping bag when camping in a tent. This adds weight and bulk to your gear. Bivies add around 5-10 degrees of warmth to your sleeping bag depending on the type and model.
• Visibility is poor- When inside a tent, you can’t really see out other than through the door. This can be annoying when you just want to look at the stars or enjoy the view. It can also be dangerous. If a person or animal is approaching your tent, you can’t see them. If you hear a spooky noise in the night, you have to get out of your tent to see what it is. In a bivy, you can easily keep an eye on your surroundings at all times.
• Tents are legal in fewer places- A lot of cities prohibit the use of tents within city limits. This is to prevent tent cities from forming. Often times there is no law against bivies. This is kind of a loophole but it does open up the possibility of wild camping locations.
• There are more pieces and parts- Tents have poles, stakes, guy lines, floor savers, rainfly, and zippers. Any of these parts can get lost or damaged making your tent either unusable or less effective.
• You can’t fly with a tent in a carry-on bag- According to the TSA, you must pack tent poles and stakes in a checked bag. This adds cost to your flight and takes more time.
• You are less connected to nature- In a tent, you are basically in your own little room, isolated from the environment.

When Should You Choose a Bivy?

As you can see, bivy sacks aren’t ideal for every environment. Bivvies work best in arid environments as well as mountainous regions that are relatively dry. Examples include the Rockies, Sierra Nevada, Alps, Atlas, and the Andes. Additionally, bivvies work well in cold and even snowy environments during the winter. Bivvies work great snow cave camping.

Generally, you’ll want to avoid camping in a bivy during hot summer months or in humid environments. There just isn’t enough airflow to allow sweat to evaporate away. The inside gets clammy and uncomfortable very quickly. You’ll also want to avoid using a bivy during peak bug season. Having insects fly so close to your face gets annoying and makes it nearly impossible to get a decent night of sleep. 

When Should You Choose a Tent?

Tents work well in hot and humid environments like the Appalachian Trail during the hot summer months. They allow some airflow so you stay a bit cooler. Tents also work well in wet regions. A tent that has been properly seam-sealed will keep you perfectly dry even in the heaviest of rain. Additionally, tents work well in buggy areas. They seal up completely and keep the bugs far enough away that you can’t hear them too much.  

Types of Bivy Sacks

When it comes to choosing a bivy sack, you have a number of design options to consider. Which bivy you choose depends on the climate you camp in, how often you plan to use it, how much protection you need, your body size, your budget, and more.

Below, I’ll outline some of the most common types of bivy sacks to help you decide which is best for your next camping trip. I’ll also make a few bivy sack recommendations.

Traditional Bivy Sack

These are your standard, no-frills bivies. They are usually made of waterproof breathable material and have an open face without a bug net. Basic bivies are a great lightweight shelter to carry as a backup or for those times where you’re not sure if you’ll have to camp or not. These usually aren’t 100% waterproof so you’ll probably want to pair them with a tarp if you expect rain. 

A popular basic bivy is the S.O.L. Escape Bivy. 

Ultralight Bivy

These are for the minimalist. Most models feature a waterproof bottom made of silnylon or Dyneema. The top is made of a lightweight breathable water-resistant material like Argon or Pertex Quantum. Most models zip fully closed with a chest or side zip with a bug net over the face. They usually weigh around 4.5-7 ounces (about 128-198 grams). Keep in mind that you’ll need to pair these with a tarp as they aren’t waterproof, just water-resistant. 

Check out Borahgear.com for some fair priced, custom ultralight bivy options. The MLD superlight is also a popular option. 

Standalone Bivy

These bivies are standalone shelters that don’t require a tarp to keep you dry. They are made of waterproof materials like Gore-Tex or Pertex. Most include a few additional features to make you more comfortable including a bug net, small poles to keep the fabric off of your face, and better ventilation to help keep condensation at bay.

Military Surplus Bivy

Militaries around the world issue bivy sacks for soldiers to camp in out in the field. A variety of options are available from several different countries. These are known for their durability. They need to be tough to put up with the demands of the military. Designs vary. Most are waterproof. Some offer bug netting and some leave the face open. These are often pretty affordable because they are mostly used. 

One of the best is the USMC Improved 3 Season bivy. The Dutch military bivy is also a popular option.

Tent/Bivy Hybrid

These shelters combine the best of both worlds. They are basically just a small tent that covers your face while your body extends outside in a traditional bivy. The benefit is that you have a bit more space to move around and the material is held off your face by the poles.

Emergency Bivy

These are designed for one purpose: to keep you alive in worst case scenarios. They use insulating and reflective material to trap your body heat and keep you warm. Most models are designed to work on their own without a sleeping bag. Emergency bivies are lightweight and are made to only last for a few uses. These are good to carry for a backup.

Tip: If you decide to pair an emergency bivy with a sleeping bag, make sure you put the bivy inside of your sleeping bag. It acts as a vapor barrier liner or VBL. This means it keeps the humidity inside the liner to help keep you warm. If you put your sleeping bag inside the emergency bivy, you’ll wake up with a soggy sleeping bag.

For more info on VBLs, check out this excellent article from Andrew Skurka.

Four Season Bivy

These are designed to be used as stand-alone shelters in all weather conditions. Rain, snow, high altitude, and extreme temperatures are no problem for four-season bivies. You can camp on top of a mountain in the middle of winter. As long as you have a good sleeping bag, you’ll stay warm and dry. They work great for snow camping or camping in high elevation areas. If you plan to camp above the tree line, consider a bivy.

Bug Bivy

Bug bivies are basically mesh bug nets with a bathtub floor sewn on. They zip completely closed to keep mosquitos, flies, ants, and other critters out. These are great for camping warm, tropical climates because they breathe very well. Condensation isn’t an issue. The drawback is that they offer no protection from the rain. You’ll need to pair your bug bivy with a tarp.

The Outdoor Research Bug Bivy Sack is a popular option. 

Bivy Materials

Bivies are often made of two different types of fabric. The top, the part that sits over your body, is a water-resistant breathable material. These are generally DWR treated. Examples include Argon and Pertex Quantum.

The bottom layer, the part that goes under your body, is waterproof. Examples include Dyneema and silnylon. This two-material design is great if you plan to pair your bivy with a tarp.

If you want to use your bivy as a stand-alone shelter, the entire bivy should be made of a waterproof breathable material. These are usually multi-layer fabrics like Gore-Tex. They are designed to allow water vapor to exit but not let liquid water in.

Final Thoughts

Reducing your pack weight allows you to hike, bike, or travel faster and more comfortably. One way to cut a significant amount of weight is to switch from a tent to a bivy bag. You’ll cut at least a pound immediately. You’ll also eliminate bulk from your pack by eliminating the poles, footprint, and a bunch of material. For the minimalist, this is appealing. Of course, there are some drawbacks. Bivy sacks don’t work well in every environment.

The best shelter for you depends on where you’re camping, the climate, and your personal preference. Hopefully, this guide helps you choose the best camping shelter for your next trip. 

Do you use a bivy sack or tent? Share your experience in the comments below!

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More from Where The Road Forks

• Is Camping Safe? Avoiding Wild Animals, Insects, and Injury
• Do I Need a Camping Pillow?
• Freestanding Vs Non-Freestanding Tents

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