Hollowing Out
Part of Emergency Shelter
Carving the interior of a quinzhee is where your snow pile becomes a shelter — work methodically from top down to create a warm, structurally sound dome.
Before You Start
Confirm the mound has settled for the required time (see Snow Mounding). Test readiness by pressing your open hand firmly against the surface. If it sinks in more than 2-3 cm, the snow has not sintered enough. Wait longer.
Gather your tools before beginning:
- Digging tool — shovel, pot, flat piece of wood, or sturdy stick
- Something to move snow out — a tarp, sled, large bag, or your shovel
- A long stick — for poking the ventilation hole from inside
- Headlamp or candle — interior becomes dark quickly
If you inserted guide sticks during mounding, verify they are still in place. Look for the slight dimples where sticks enter the surface.
Digging the Entrance Tunnel
The entrance is the most important structural and thermal element of the entire shelter.
Step 1 — Choose the downwind side of the mound. If wind direction is unclear, look for which side has the least snow drift accumulation — that is the lee side.
Step 2 — Begin digging a tunnel at ground level, aimed at the center of the mound’s base. Make the tunnel just wide enough for your shoulders (60-75 cm / 24-30 inches) and tall enough to crawl through (50-60 cm / 20-24 inches).
Step 3 — Angle the tunnel floor slightly downward for the first 30 cm, then level off, then angle slightly upward as you enter the main chamber. This creates a cold air trap: the lowest point of the tunnel floor sits below the sleeping platform. Cold air, being denser, sinks to this low point and drains out the entrance.
Cross-section (not to scale):
___________
/ \ <- Domed ceiling
/ WARM AIR \
/ ~~~~~~~~~~ \ <- Sleeping platform (raised)
| ============ |
| ============ | <- Platform level
|__________________|____
\ / <- Entrance tunnel
\ / <- Cold air trap (lowest point)
\/
Step 4 — Keep the entrance as small as practically possible. A large entrance bleeds warm air. You should have to duck and squeeze slightly to enter. If you have a backpack or snow block to partially seal the entrance after you are inside, size the tunnel for that.
Hollowing Sequence
Work from the ceiling down. This is counterintuitive — most people want to dig sideways — but there are two critical reasons:
-
Structural: The dome ceiling is the most important structural element. Shaping it first, before removing support snow below, lets you control the dome profile while the walls still provide support.
-
Practical: Snow you remove from the ceiling falls to the floor where you can scrape it toward the entrance and push it out. If you hollow the floor first, you have nowhere to put ceiling snow.
Step 1: Establish Ceiling Height
Once inside the mound through your entrance tunnel, begin removing snow directly above you. Work upward until you reach the desired interior height:
| Shelter Size | Target Ceiling Height | Minimum Clearance (sitting) |
|---|---|---|
| 1-person | 60-75 cm (2-2.5 ft) | 50 cm above platform |
| 2-person | 75-90 cm (2.5-3 ft) | 60 cm above platform |
| 3-4 person | 90-120 cm (3-4 ft) | 75 cm above platform |
You do not need to stand inside. Sitting height while on the sleeping platform is sufficient and keeps the shelter smaller (smaller = warmer).
Step 2: Shape the Dome
Watch for guide sticks
When your digging tool or hand hits the inner tip of a guide stick, STOP digging in that direction immediately. The wall is now at the minimum safe thickness of 30 cm. Move to a different area.
Work the ceiling into a smooth, continuous dome curve. The apex should be at or near the center of the shelter. Remove any bumps, ridges, or flat spots — these are drip points. Water from your breath condenses on the cold ceiling and needs to flow smoothly down the curved walls to the floor, not drip onto you.
Test the dome by running your gloved palm over the entire ceiling. It should feel like the inside of a bowl — smooth and uniformly curved.
Step 3: Widen the Walls
After the ceiling is shaped, begin widening the interior by removing snow from the walls. Work downward from the ceiling junction, keeping the wall profile vertical or slightly outward-leaning at the base. This creates more floor space without compromising the dome.
Maintain the dome curvature where walls meet ceiling — no sharp corners. Sharp inside corners concentrate stress and are weak points.
Step 4: Carve the Sleeping Platform
The sleeping platform should be a raised shelf of packed snow running along one or both sides of the interior, opposite the entrance. Key dimensions:
- Height above entrance floor: 30-45 cm (12-18 inches) minimum
- Width: At least 60 cm (24 inches) per person
- Length: Full body length — 180-200 cm (6-6.5 feet)
- Surface: Flat and smooth, packed firm
The platform is essentially a bench of snow that you leave in place while hollowing the rest. Do not hollow below platform level except for the entrance tunnel and a small gear storage area.
Step 5: Create a Gear Niche
Carve a small alcove in the wall opposite the sleeping platform (or at the head/foot end) for storing boots, packs, and gear. Keep gear off the sleeping platform to maximize sleeping space and off the floor to keep it out of the cold air trap zone.
Step 6: Ventilation Hole
From inside, push a stick (at least 50 cm long) through the ceiling at the highest point of the dome, angling it at roughly 45 degrees. Twist it as you push to create a clean hole 8-10 cm (3-4 inches) in diameter.
Check from outside that the hole is clear. Place a small branch across the outer opening to prevent snow from drifting in while still allowing airflow.
Step 7: Smooth Everything
Final pass: smooth all interior surfaces with your gloved hand. Pay special attention to:
- The ceiling dome — no drip points
- The junction between ceiling and walls — smooth curve, no edges
- The sleeping platform surface — flat and firm
- The entrance tunnel ceiling — dome it slightly to prevent drips on your face while entering
Managing Excavated Snow
You will remove roughly 60-70% of the mound’s volume. That is a substantial amount of snow that must go somewhere.
Method 1 (best): Have a partner outside who pulls snow out of the entrance as you push it. Use a tarp or sled as a conveyor.
Method 2 (solo): Push snow toward the entrance with each digging stroke. Periodically back out of the tunnel and clear the snow pile that accumulates at the entrance. This is slow but necessary — snow blocking the entrance traps you and blocks ventilation.
Method 3 (gear available): Fill stuff sacks, bags, or a pot with loose snow inside, pass or drag them to the entrance, dump outside, repeat.
Never let excavated snow block your exit
If the entrance becomes blocked while you are inside, you can become trapped in an airtight space. Every few minutes, check that the entrance is clear. If working solo, back out frequently to clear debris.
How to Know You Are Done
Run through this checklist before declaring the shelter complete:
- Ceiling is smoothly domed with no flat spots or drip points
- All guide sticks have been reached (or walls are at least 30 cm thick everywhere)
- Sleeping platform is raised 30+ cm above entrance tunnel floor
- Ventilation hole is open and unobstructed
- Entrance tunnel has a cold air trap (low point below sleeping level)
- Interior is sized for occupants and no larger — tight is warm
- Entrance can be partially blocked with a pack or snow block
- Exterior is marked with a stick or dark objects
Key Takeaways
- Always hollow from the ceiling down — shape the dome first while wall snow still provides structural support.
- Stop digging when you hit guide sticks — walls below 30 cm are structurally weak and poorly insulating.
- Smooth the entire ceiling into a continuous dome curve so meltwater runs down walls instead of dripping on you.
- The sleeping platform must be higher than the entrance floor — cold air sinks, so you sleep in the warm layer.
- Keep the entrance small and check it frequently during hollowing — a blocked entrance traps you in an airtight space.