Guide · Fencing
Privacy fences planned around sightlines
Building to the maximum permitted height is the reflex. A better start is finding where you sit, what overlooks that spot, and what would block the view.
Start where you sit
A privacy fence only works if it interrupts a specific line of sight. That line runs from your seat to whoever can see you. Sit in the chair you actually use, not the middle of the lawn, and look around. That view is the one worth blocking.
Three outcomes come up repeatedly. The view may come from an upstairs window, where no permitted fence helps and a tree or pergola does. It may come from one narrow angle, where a raised panel over a few metres beats raising the whole perimeter. Or the fence is adequate and the seating simply faces the wrong way.
What height actually buys
Moving from a low boundary fence to full privacy height changes a yard completely. Adding a little more beyond that rarely does. It brings extra wind load, heavier posts, deeper footings and a yard that starts to feel enclosed.
The ceiling is also not yours to set. Each municipality writes its own fence by-law, with different limits for different parts of a lot and tighter rules for corner lots and pools. Confirm the applicable limit with your municipality before design.
Board styles
- Solid butt-jointed. Full screening and the highest wind load, with gaps appearing as boards shrink. Best on a sheltered line.
- Board-on-board. Overlapping boards on alternate faces, so drying never opens a see-through gap. Both sides look finished, which helps with neighbours. It uses more lumber.
- Shadowbox. Boards alternate faces with a set space between, letting air pass and easing wind load. Private straight on, less so at an angle, which suits most seating layouts.
- Horizontal. Clean and contemporary but less forgiving. Long horizontal boards sag, so posts sit closer or rails get heavier. Every post must be dead plumb, since horizontal lines expose any error.
Wind is a structural load
A solid privacy fence behaves like a sail. Wind on each unbroken panel passes into rails, posts and footings, which is why tall solid runs need heavier posts.
Exposure raises that load: an open view across a neighbouring yard, the crest of a grade change, a corner lot with nothing upwind. On those lines, board-on-board or shadowbox reduces the force. A lattice top relieves the upper boards, where tall solid fences tend to fail first.
Footings carry the extra load
Footing depth below frost applies to every style and is covered in the fencing hub. What a privacy fence adds is load, so post size and spacing deserve closer attention than on an open boundary run.
Gates
As the only moving part, a gate fails before the rest of the fence. Give it heavier posts than the run, diagonal bracing in the correct direction, hinges rated for its weight and enough bottom clearance to swing after frost heave. Make it wide enough for a wheelbarrow, or for a compact excavator if ground work may follow.
Talk to the neighbour first
Shared-boundary rules sit on the fencing hub. For a privacy fence, that conversation should also settle which side shows the rails and where height is genuinely needed. The sightline work above makes that discussion much shorter.
Replacing an existing fence rather than starting fresh? See the replacement guide.
Alternatives
Options that beat extra height
Raise one section
Lift only the stretch facing the problem and keep the rest at standard height. The yard stays open.
Plant above the fence
Trees are the only screen for an upstairs window. They take time, which is a reason to plant early.
Cover the seating
A pergola or large umbrella blocks the downward view a fence cannot reach.
Turn the furniture
Repositioning seating costs nothing and is rarely tried first.
Add a lattice top
Extra apparent height and screening with less wind load and a lighter look.
Screen the one gap
Most complaints trace to a single angle. Address that angle, not the whole perimeter.
Questions
Privacy fence questions
How tall can a privacy fence be?
Your municipality sets the limit, so check its fence by-law before design. The permitted height usually varies across a single lot, often higher at the rear than the side and lower along street frontage. Corner lots and pool enclosures follow stricter rules. Confirming early avoids building a fence an officer can order shortened.
Will a taller fence give me more privacy?
Only to a point, and less than most people expect. Privacy depends on sightlines, and no permitted fence height blocks a view from a second-storey window. When the overlooking comes from above, planting, a pergola or a well-placed umbrella does more than extra board height.
Board-on-board, shadowbox or solid?
Pick by exposure and how private the fence must stay as the wood dries. Solid butted boards screen fully at first but catch the most wind and open gaps as they shrink. Board-on-board overlaps alternate faces, so it stays private through shrinkage and looks finished from both sides. Shadowbox leaves a deliberate gap between faces, easing wind load, but it is fully private only when viewed square on.
Should I stain it?
Cedar does not need it; left alone it weathers to an even silver grey. Pressure-treated lumber does benefit from a finish, but only after it has dried, which usually means waiting a season. If you plan to finish either species, do it before the first winter.