How to read a floor plan
What every line and number on a floor plan means. The complete beginner's guide.
A floor plan is a top-down view of a building, drawn as if the building has been sliced horizontally about 4 feet above the floor. Once you know what the conventions mean, you can read any plan.
In this guide
- 1
Orientation
North arrow somewhere on the plan — usually top-right or bottom-right corner. North up is conventional but not required. Read this first so you know which walls face which direction (matters for daylight, view, climate).
- 2
Walls
Two parallel lines = a wall. The space between them = wall thickness. Thicker walls (often shaded or hatched) = exterior or load-bearing. Thinner walls = interior or non-load-bearing. Single line = sometimes a half-wall, railing, or partial wall.
- 3
Doors
Gap in the wall + quarter-circle arc = hinged door (the arc shows the swing). Gap in the wall + two short parallel lines = sliding door. Gap with the door drawn inside the wall = pocket door. Gap with no door shown = opening (no door).
- 4
Windows
Two parallel lines crossing the wall = window. Sometimes with an additional shorter line indicating sill or sash.
- 5
Dimensions
Lines with arrows at both ends and a number = a dimension. The number is the length of what the line spans. Typical dimensions shown: - Outer perimeter of each side - Interior room dimensions - Door and window positions on walls - Total dimensions of the building
- 6
Scale
Scale notation somewhere on the plan: '¼" = 1'-0"' (quarter inch = one foot) is the most common residential scale. '1/8" = 1'-0"' for larger buildings. Means every quarter inch on the paper = 12 inches in real life. To measure, hold a ruler to the line; divide by 4 (or the relevant ratio).
- 7
Symbols
Outlets, switches, lights, plumbing, HVAC — each has a standard symbol. See floor plan symbols for the full reference.
- 8
Furniture
Drawn from above, to scale. - Sofa: rectangle with curved back. - Bed: rectangle with rounded headboard. - Dining table: round or rectangular shape with chair indicators. - Toilet: oval + small rectangle. - Sink: rectangle or oval.
- 9
Room names and areas
Each room labelled with name (e.g. 'BEDROOM', 'KITCHEN', 'LIVING') and often area (e.g. '12-0 × 14-0' or '168 sq ft').
Frequently asked questions
What does a circle with a line mean on a floor plan?
A circle with a line is often a door swing arc — the quarter-circle showing how a hinged door swings. Other circles can be outlets (with two slots) or lights (with X).
How do I know which way a floor plan faces?
Look for the north arrow — usually in a corner of the plan. It points to true north (or sometimes magnetic north).
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