Bivys & Shelters

Bivvys and shelters are minimalist alternatives to tents used for outdoor sleeping, especially in hiking, mountaineering, and ultralight backpacking. Here's what they are and how they differ:

BIVVY (BIVOUAC) SACKS:

What is a bivvy?
A bivvy sack is a compact, waterproof (or water-resistant) shell that goes around your sleeping bag to protect you from the elements. It’s essentially a personal-sized shelter.

Key Features:

  • Ultra-lightweight: Often under 1 kg (2 lbs)

  • Very compact: Packs down to the size of a water bottle

  • Water & wind resistant: Offers protection from rain, dew, and wind

  • Breathable versions: Some have built-in mesh panels to reduce condensation

  • Emergency versions: Some are reflective and meant for survival situations only

Pros:

  • Super light and fast to set up

  • Great for minimalist hikers or emergency kits

  • Can be used inside tents for added warmth

Cons:

  • Limited space (no room for gear or movement)

  • Can get condensation inside

  • Less protection in heavy rain or bad weather

SHELTERS:

What is a shelter?
An outdoor shelter is a more open, lightweight structure that provides overhead protection from the elements. These include tarps, pyramid shelters, or open tents.

Types of Shelters:

  • Tarp shelters: Just a tarp strung between trees or poles

  • Pyramid shelters: Cone-shaped with a central pole, more enclosed

  • Tarp tents: Tarps shaped or rigged like tents, sometimes with bug netting

Pros:

  • Lightweight and flexible setups

  • Can cover more than one person

  • Good airflow and minimal condensation

Cons:

  • Not fully enclosed (less bug or rain protection unless modified)

  • Requires setup skill and environmental conditions (trees, flat ground)

Summary:

TypeWeightProtectionSpaceBest For
Bivvy Very light Moderate (personal)   Minimal   Emergency, solo hiking, ultralight
Shelter Light to moderate   Moderate to good  Varies Ultralight camping, flexible setups

Want help picking between them for your trip or comparing specific models?