How to Block a Second-Story Neighbor’s View

Why the fence at the boundary does not work

Take a typical case: the neighbor’s second-floor window puts eyes about 4.60 m (15 ft 1 in) above your ground. Your patio starts 9 m from their wall and ends at 13 m, and you want seated people (heads about 1.2 m) out of sight.

Where the barrier stands	Height needed (seated, no margin)
At the boundary, 4 m from the window	3.56 m (11 ft 8 in)
Halfway, 6.5 m	2.90 m (9 ft 7 in)
Beside the patio, 8.7 m	2.33 m (7 ft 8 in)

The sightline drops as it travels, so the further it has travelled when it meets the barrier, the lower it is. At the boundary it has barely started descending. Open this comparison in the planner to see it with your own numbers.

What you hide matters as much as where

With the screen beside the patio, the height needed depends heavily on what should be hidden:

• People reclining on loungers (0.9 m): 2.13 m (7 ft 0 in)
• People seated at a table (1.2 m): 2.33 m (7 ft 8 in)
• People standing (1.8 m): 2.73 m (9 ft 0 in)

Complete privacy for standing people from an upstairs window is rarely achievable with a vertical screen. Deciding what you actually need — a private dining spot, not an invisible lawn — is often what makes the project feasible.

Moving the seating can help more than a taller screen

If the screen stays just in front of the seating (0.3 m) and the 4 m deep seating area moves farther from the neighbor, the required height falls:

Seating starts at	Screen height needed
6.00 m (19 ft 8 in) from the window	2.67 m (8 ft 9 in)
9.00 m (29 ft 6 in) from the window	2.33 m (7 ft 8 in)
12.00 m (39 ft 4 in) from the window	2.12 m (7 ft 0 in)
15.00 m (49 ft 3 in) from the window	1.97 m (6 ft 6 in)
20.00 m (65 ft 7 in) from the window	1.81 m (6 ft 0 in)

This works because the screen then sits on a longer, already-descended stretch of the sightline.

Options that suit steep views

A screen close to the seating

The most direct fix. Expect it to be wider than a screen further away: near the seating, the sightlines to the left and right edges of the area are spread apart. The planner’s top view shows the width.

Overhead cover

A pergola with slats, an awning, a shade sail or a large tilting umbrella intercepts steep sightlines from above with relatively little material. It works best when the viewpoint is high and close; for a window across a wide yard the cover must extend a long way toward the neighbor. The geometry is explained in privacy from upstairs neighbors.

Trees and tall planting

A canopy positioned between the window and the seating sits where steep sightlines pass. Remember growth time, seasonal leaf loss and that canopies are rarely fully opaque.

Combining elements

A moderate screen plus an umbrella can cover what neither does alone. Model the screen in the planner, note which part of the area remains visible, then decide what covers that part.

Measuring a neighbor’s window without trespassing

• Count stories: residential floors are typically about 2.7–3.2 m apart. A second-floor sill often sits around 3.5–4 m above ground.
• Count courses: bricks, blocks or siding boards give a surprisingly accurate scale from your own yard.
• Use a known height: a photo that includes a door (about 2 m) or a fence of known height lets you scale.
• Check on site: hold a pole at the proposed screen position and look from your seating toward the window — if you can see the window over the pole, they can see you.

Screens and fences near boundaries are frequently subject to height limits and permits. The planner reports geometry only; check local rules before building.

Frequently asked questions

How tall does a fence need to be to block a second-floor window?

At the boundary it usually needs to be much taller than fences are allowed to be. In the example on this page — a viewpoint at 4.6 m, a patio 9–13 m away and a fence 4 m from the window — hiding seated people takes 3.56 m (11 ft 8 in). A screen placed beside the patio needs 2.33 m (7 ft 8 in) instead.

Do trees work against second-story views?

A tree with a canopy between the window and your seating can work well because the canopy sits exactly where steep sightlines pass. Use the planner with the canopy’s underside and top in mind: the canopy must reach above the sightline at its position. Deciduous trees lose that cover in winter, and young trees take years to reach the height you need.

Is it better to move my seating or build a taller screen?

Often moving the seating helps more than people expect. With a screen kept just in front of the seating, moving the seating farther from the neighbor lowers the height needed, as the table on this page shows. Check both in the planner by moving the private area.

What if the window is not directly opposite my patio?

Enter the window’s left/right offset in Advanced mode. The height calculation uses the real 3D distance along each sightline, and the top view shows how far the screen must extend to the side.