Privacy Fence.
Block the line of sight.

Three tiers of solution to block sightlines from neighbours: 1) Solid privacy fence — 6 ft vinyl, wood board, or composite at $30-70 per linear foot supply; full screening, hard boundary, code-permitted in most residential zones up to 2.0 m without permit. 2) Lattice top with solid bottom — 4 ft solid + 2 ft lattice or trellis for vines, $25-50/ft; lets light through, reads less imposing than full solid. 3) Living screen — cedar hedge or columnar Serbian spruce planted 24 inches off the property line, full screen in 4-6 years, $200-400 per tree at install. Hybrid approach is common: solid fence on the close-pressure side (back neighbour), open picket or hedge on lower-pressure sides. Check zoning before going to 6 ft — most municipalities allow 1.8-2.0 m in side/rear yards without permit; height limits in front yards are usually 1.0-1.2 m.

True one-way visual fencing doesn't exist outdoors — physics doesn't let a passive material be transparent in one direction and opaque in the other. The closest practical solutions: 1) Angled louvre / shadow-box fence — overlapping vertical boards offset front and back, creates near-full screening from a perpendicular sightline but allows you to see through at acute angles (looking down the fence line). 2) Horizontal louvre with slight downward tilt — angles like venetian blinds, designed so a standing neighbour sees opaque while a seated person inside sees through. 3) Dense hedge with a clear line of inside footpath — the hedge depth creates an asymmetric view. 4) Solid fence with strategic gap or window opening at your seated eye level. For a real "see-out, not-in" effect inside your yard, position seating where the screening geometry favours you, or use a 6-ft solid fence and accept losing the long sightline outward.

Cheapest privacy fence options by ascending cost: 1) Privacy slats on existing chain-link — $4-10 per linear foot supply if chain-link is already up; converts an open fence to 75-90% screen in a weekend. 2) Privacy windscreen fabric — $2-5 per foot supply, zip-tied to existing chain-link or temporary frame, 85-95% screen, 5-7 year UV life. 3) Pressure-treated wood board fence at 6 ft — $25-40 per linear foot supply, install yourself in a long weekend for a 100-ft run, 12-20 year life with annual stain. 4) Cedar board fence — $30-50 per linear foot supply, ages to silver-grey naturally, longer maintenance interval than PT. 5) Vinyl tongue-and-groove privacy panel — $35-60 per linear foot supply, no painting, 25+ year life. For lowest absolute upfront, slats on existing chain-link wins; for lowest 25-year cost, vinyl wins.

If you already have a chain-link, picket, or rail fence, the cheapest way to add privacy without replacing it: 1) Privacy slats (chain-link only) — $4-10 per linear foot supply, drop-in vertical slats, 75-90% screen, lockable bottom strip. 2) Reed or bamboo roll — $3-8 per foot, zip-tied to any open fence, natural look, 3-5 year life. 3) Windscreen fabric — $2-5 per foot, vinyl-coated polyester, best on chain-link or wire panel. 4) Plywood or cedar boards on furring strips attached to picket fence — converts to solid wood at $8-15 per foot in materials. 5) Climbing plants on a wire trellis fastened to the existing fence — long lead time but free at year 3+. For an existing wood picket or board fence with gaps, scab-on cedar slats inserted between existing boards close the gaps for $8-12 per foot supply.

Cheapest new privacy fence from scratch: pressure-treated 1×6 board fence, 6 ft tall, on 4×4 PT posts set in concrete. Materials for 100 linear feet of perimeter (assume 6-ft post spacing, 17 posts, 600 board-feet of 1×6, 200 board-feet of 2×4 rails, 17 bags of fast-set concrete, screws): $1,800-3,000 supply depending on lumber market. Install in 2 weekends for two people with basic tools (post-hole digger or rented auger, drill, level, miter saw). DIY total ~$20-30 per linear foot. Going pro on the same fence runs $40-65 per linear foot turnkey. Where to save: buy lumber direct from a mill, not big-box; use brown PT for posts and cedar only for the visible boards; build it 5 ft instead of 6 ft if your zoning allows. Where not to save: post depth — set below frost or it leans inside 5 years.

Maximum height for a privacy wall on a residential patio in Canada is set by your municipal zoning bylaw — there's no single national or provincial number. Common patterns: detached residential side and rear yards typically allow 1.8 m to 2.0 m (6.0 to 6.5 ft) without permit; over that requires a fence or accessory-structure permit. Toronto allows 2.0 m in side/rear without permit; Vancouver allows 1.83 m; Montreal varies by borough but is commonly 2.0 m. Front yards are usually limited to 1.0-1.2 m. Attached to a deck or elevated patio: if the privacy wall is structurally part of the deck rail, height limits switch to building-code rail requirements (1.07 m / 42 in. for residential decks under 1.8 m above grade, 1.07 m for higher) and the privacy panel above the rail is treated as a screen accessory. Check your zoning bylaw specifically for "fence height" and "accessory structure height."