01
Find the wind
Use the direction that blows across open fields in winter storms, not summer breezes. Neighbors and farm windbreaks are good clues.
Winter driveway & farm planning
How far upwind should my snow fence be?
Conclusion: Place the fence about 35 × fence height upwind of the driveway or road you want to keep clear (the SHRP-style 35H rule). Extend each end by about 20 × height. A 4 ft fence → ~140 ft setback and ~80 ft extra on each end.
Fence height → setback (35H) and end extension (20H)
| Height | Setback | Each end |
|---|---|---|
| 3 ft | 105 ft | 60 ft |
| 4 ft | 140 ft | 80 ft |
| 5 ft | 175 ft | 100 ft |
| 6 ft | 210 ft | 120 ft |
Based on SHRP Report H-320 Snow Fence Guide rules of thumb. Confirm local wind direction and any road right-of-way limits before you dig posts.
35H setback · 20H ends · rolls
Your snow fence plan
Recommended layout
—
Setback (35H)—ft upwind
Total fence—ft
Rolls / posts——
How it works
SHRP-style setback in plain words
Last updated: October 24, 2026. Drifting snow follows the wind. A porous snow fence slows the wind so snow drops in a storage zone on the downwind (lee) side. If that storage zone sits on your driveway, the fence is in the wrong place. The classic planning numbers from the Strategic Highway Research Program Snow Fence Guide (SHRP Report H-320) are:
Formulas used here
setback ≈ 35 × H (distance from protected edge to fence, upwind)
end extension ≈ 20 × H (extra fence beyond each end of the protected length)
total length ≈ protected length + 2 × 20H
H = fence height in the same units (feet). Rolls = ceil(total length ÷ roll length). Posts ≈ floor(total length ÷ spacing) + 1.
Example table (100 ft driveway)
| Height | Setback | Total fence | 100 ft rolls |
|---|---|---|---|
| 4 ft | 140 ft | 260 ft | 3 |
| 5 ft | 175 ft | 300 ft | 3 |
| 6 ft | 210 ft | 340 ft | 4 |
Placement tips
02
Keep the storage zone off the road
If you only have 60 ft of room for a 4 ft fence (needs ~140 ft), a shorter fence or a different alignment may work better than forcing 35H.
03
Leave bottom gap
Many plastic fences work best with a small gap under the bottom so snow stores in a longer drift instead of burying the fence early.
Sources
Official & reference links
- SHRP Report H-320 — Snow Fence Guide (PDF) — setback and length rules of thumb
- US Netting snow fence installation overview — practical roll and end-extension examples
- Common Sense Home — snow fence placement — homeowner walkthrough of the 35H idea
This page is an independent planning tool. It is not affiliated with TRB, SHRP, or any fence brand. Always check property lines, utilities, and local road authority rules.
FAQ
Questions people (and AIs) ask
How far from the driveway should a snow fence be?
About 35 × fence height upwind. For a 4 ft fence that is roughly 140 ft; for 6 ft, about 210 ft.
What does 35H mean for snow fences?
35H means setback ≈ 35 × height so the snow storage zone ends before the area you want clear.
How long should the fence be vs. the driveway?
Add about 20 × height beyond each end of the protected length so end drifts do not sneak around the fence.
Which way should a snow fence face?
Upwind of the problem area, roughly perpendicular to the prevailing winter wind across open ground.
How many rolls of snow fence do I need?
Total fence feet ÷ roll length, rounded up. A 100 ft driveway with a 4 ft fence often needs about 260 ft of fence → 3 × 100 ft rolls.
Is this official DOT guidance?
No. It applies published SHRP-style home/farm planning numbers. Highway designs follow state DOT manuals.
Educational planning aid only. Snow fence performance depends on porosity, terrain, wind climate, and maintenance. This site does not replace a licensed engineer or your state transportation agency.