If you’ve received a site plan from a drafter or need to review one before submitting to your building department, this guide helps you understand what you’re looking at.
I’m Engineer Wasim of Site Plans Online USA.
The Basic Orientation
A site plan is a top-down view of your property, like looking straight down from above. Everything is drawn to a consistent scale, meaning if 1 inch on the drawing equals 20 feet in the real world, that proportion holds everywhere on the plan.
Finding your bearings:
- Look for the north arrow — it tells you which direction is north, so you can identify the front of the property (facing the street) vs. the back
- Find the title block — usually in a corner, which lists the property address, owner name, and scale
- The property lines are the outer boundary of the lot, shown as a thick or bold border
What Each Line Type Usually Means
- Solid thick lines — property boundaries (lot lines)
- Solid medium lines — existing structures (your house, garage, etc.)
- Dashed lines — usually proposed new construction or easements
- Dotted lines — sometimes setback lines showing the buildable zone
- Thin dimension lines — measurements between elements
Reading the Scale
If the plan says “Scale: 1″=20′”, it means every 1 inch on the drawing represents 20 feet on the actual property. A graphic scale bar (a small ruler-like bar) should also appear so you can verify measurements visually.
Example: If your house footprint measures 2.5 inches on the plan, and the scale is 1″=20′, the actual house is 50 feet long.
If the plan doesn’t have a scale or says “not to scale,” it’s not a valid permit site plan and needs to be corrected.
Finding the Setbacks
Setbacks are the distances from the proposed structure to the property lines. On a permit site plan, they appear as dimension arrows from the edge of the proposed structure to the nearest property line, labeled in feet.
You should see setbacks from all four sides of the proposed structure: front (toward street), rear, left side, and right side.
If a setback dimension is missing — that’s a correction notice item. Every distance must be explicitly labeled.
How to Check If a Plan Is Complete
Use this quick check:
North arrow present?
Scale stated in text AND shown as graphic bar?
All lot lines shown with dimensions?
Every structure on the property shown?
Proposed project clearly labeled?
All four setbacks labeled in feet?
Impervious surface calculation shown?
Title block complete?
For a full checklist: Construction Site Plan Checklist To check your plan online: Site Plans Checker Tool
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