How to read a floor plan

A floor plan looks like a map of a home seen from above, as if the building had been cut horizontally about a metre above the floor. Once you know a handful of conventions, most plans are easy to read.

Walls

Walls are drawn as thick lines or filled bands. Thicker bands are usually external or load-bearing walls; thinner ones are partitions. Hatching (diagonal lines) inside a wall is a common way to show that it was cut.

Doors

A door is shown as a gap in the wall with a straight line for the door leaf and a quarter-circle arc for its swing. The arc tells you which way the door opens and how much floor it needs — important when you plan furniture.

Windows

Windows are shown as thin double or triple lines inside the wall band, often in a lighter colour. A plan alone does not show the sill height; that is usually in a schedule or a section drawing.

Dimensions

Dimension lines have small ticks or arrows at each end and a number in the middle. Check whether the plan measures:

• inside faces (the room's usable size), or
• centre lines of walls, or
• outside faces (the overall building).

Roomdraft shows inside lengths next to each room and outer lengths along the outside of the building.

Scale

A plan "at 1:50" means 1 cm on paper is 50 cm in reality; at 1:100, 1 cm is 1 m. A scale bar lets you measure from a printout even if it was resized. Never measure from a plan that has no scale or scale bar.

Floor area

Area is usually measured inside the walls, room by room, and listed in m² or square feet. Total areas in listings may follow other rules (for example including walls or excluding low ceilings), so compare like with like.

Symbols for furniture and fixtures

Furniture is drawn as simplified shapes seen from above: a bed with pillows, a sofa with seat cushions, a toilet as an oval with a tank. They are usually at true size, which is why plans are good for testing layouts.

Ready to draw your own? Start with how to draw a floor plan.