Fence Planning Guide: From Property Lines to the Last Post Cap

1. Check rules, lines, and utilities first

Three checks before you buy a single post, and all of them are free or cheap:

• Property lines. Do not guess where your lot ends. A recent survey, your closing documents, or the plat on file with the county will show it. Building even a foot over the line can mean tearing the fence down.
• HOA and local rules. HOAs and municipalities commonly regulate fence height, style, material, and setback from the line or sidewalk. Approval can take weeks, so submit your plan early. Some areas also cap front-yard fence height lower than the backyard — check before you design.
• Utilities. Call 811 before you dig. In the US, 811 is the free national “Call Before You Dig” number. Fence post holes routinely go 2–3 feet deep — exactly where gas, electric, and communications lines live. Locators will mark them on your property within a few business days.

2. Choose a style and height

Match the fence to the job it is doing. Privacy fences (typically 6 ft) block sightlines and wind; picket or spaced-board fences mark boundaries while keeping views open; split-rail suits rural lots where the goal is a boundary, not screening. Taller is not always better — a 6-foot privacy fence catches a lot of wind, and wind is what eventually leans a poorly set post.

Typical residential heights: 3–4 ft for front yards and pickets, 6 ft for backyard privacy. Anything taller usually triggers a permit and sometimes an engineered design. Check your local height limits during the rules check above.

3. Lay out the line and set post spacing

Run a string line between your end points — corners, gates, and property corners — and keep every post on that string. A fence that wanders off the line looks bad forever, and no amount of good workmanship later fixes a crooked layout.

Post spacing: 8 feet on center is the typical spacing for residential wood and vinyl fences. Mark your post positions along the string, but plan around gates and corners first — gates get posts wherever the gate opening lands, and you never want a gate hinge post to be a compromise position. If a run does not divide evenly into 8-foot sections, shorten the last panel rather than stretching every spacing; an evenly spaced fence looks intentional, and rails that span too far will sag.

Walk the line and mark every obstacle: trees, slopes, drainage swales, and utility flags from your 811 locate. Slopes need a decision up front — stepped fencing (each panel level, dropping in steps) is simpler and typical for privacy fences, while racked fencing (panels following the slope) works better for pickets and keeps small animals from slipping under.

4. Setting the posts: depth and footing

Posts fail at the ground line, so the footing is the whole project. A widely used rule of thumb: bury at least one-third of the post's total length, with about 2 feet as a practical minimum for short fences. That means a 6-foot fence typically needs 8-foot posts set 2 feet deep or deeper. In frost-prone areas, the bottom of the post should sit below the local frost line — frost heave will push shallow posts up over winter. This is general guidance, not an engineering specification; gate posts and corners deserve more depth, and local codes may specify exact minimums.

Dig holes roughly three times the post's width in diameter — for a 4×4 post, that is about a 10–12 inch hole — with straight sides and a flat or slightly belled bottom. Set the post plumb in two directions with a level before you backfill; a post that is out of plumb on day one never gets straighter.

Concrete vs. tamped gravel

Both are legitimate; pick based on the post's job:

• Concrete gives the most rigid set. It is the standard choice for gate posts, corner posts, and end posts — anywhere the fence takes pulling or twisting loads. Slope the top of the concrete away from the post so water sheds off instead of pooling against the wood.
• Compacted gravel drains better than concrete and makes a future post replacement a matter of digging rather than jackhammering. It is a solid choice for line posts on well-drained soil. Tamp in lifts — a few inches at a time — or it will settle and the post will loosen.

Keep wood out of standing water either way. In chronically wet ground, consider steel or composite posts, or set wood posts on concrete piers above grade.

5. Plan the gates

A gate is a fence section that moves, gets slammed, and carries its own weight on two hinges — plan it like a small project inside the project:

• Width: size for what has to pass through. A walk gate is usually 3–4 ft; a mower or trailer gate needs 5–6 ft or a double gate. Measure your widest equipment, not your guess.
• Posts: gate posts take the gate's weight and every slam. Set them deeper than line posts, in concrete, and consider a 6×6 instead of a 4×4 for wide or heavy gates.
• Hardware: use hinges and latches rated for the gate's weight, and prefer adjustable hinges so you can true the gate up as posts settle. Cheap hardware is the most common reason a good gate starts dragging.
• Swing direction and clearance: decide which way the gate swings and confirm nothing — grade, steps, the fence itself — blocks it.

6. Estimate materials before you shop

With your layout done, count posts, rails, pickets, and concrete. The number that surprises most DIYers is the concrete: an ordinary 12-inch-diameter, 36-inch-deep hole with a 4×4 post needs about 4 eighty-pound bags per hole once you subtract the post itself — multiply that by 20 holes and you are at 80 bags. Run your numbers with our fence calculator, which handles post spacing, post count, rail and picket estimates, and the concrete per hole with post displacement accounted for.

Buy a few extra pickets and at least one extra post. Boards vary in quality, and a cracked picket discovered mid-build is not a reason to drive back to the store.

Frequently asked questions