The pots on the roof that need watering twice a day

The plan

Demonstration, changes are not savedBack to the answer
Heights matter more than outlines here. A fence at the right height in roughly the right place gives a far better answer than a perfect outline at the wrong height. Drag things to move them, or select one and use the arrow keys; hold shift for larger steps.
AddGroundMark

The property line

A rectangle you set the size of, not a survey. It decides one thing: whether a position is yours. Anything standing outside it is a conversation with a neighbour rather than a trip to the timber yard, and the study says so.

Nudge it
Parapet3.6 ftStair housing8.5 ftIn a pot20° upN16 ft
BuildingNot yoursCanopyShadow nowCan see inProposed

Shadows drawn for

September · 18:00 · sun 20° up, W

Nothing selected

Click anything on the plan to set its height, how solid it is and what it is called. Drag it to move it.

Where this is

Chicago (demonstration) · 30.267, -97.743 · America/Chicago

This sets how much the reported ten-metre wind slows down at seat height.