Reading a floor plan: walls, doors, windows, and scale
A quick primer on the symbols and conventions in a floor plan, and what each one means for designing or renovating your room.
Whether you drew it yourself or got it from a listing, a floor plan packs a lot of information into a few lines. Here's how to read the essentials, the same elements Kansumi extracts when you upload one.
Walls
Walls are the thick lines forming the room's outline. Thickness roughly indicates whether a wall is structural (thicker) or a partition (thinner). The inside faces of the walls define the usable room area. That's the polygon Kansumi fills and measures.
Doors
A door is usually drawn as a gap in the wall with a quarter-circle swing arc showing which way it opens. The arc matters for layout: it tells you the floor space the door needs and which side furniture should avoid.
Windows
Windows appear as a thinner double line spanning a gap in the wall. Their position and width shape natural light and where you'd place seating or a desk, and in a render, they're where daylight comes from.
Scale
Scale is what turns lines into real distances. It might be a labelled dimension ("4.2 m"), a ratio ("1:50"), or a scale bar. Without it, a plan is just a shape. This is why Kansumi asks you to confirm one real measurement. It anchors everything else to true size, so a "2.4 m sofa" is actually 2.4 m in the room.
Putting it together
Read in order (outline, openings, then scale) and a plan tells you the whole story of a space before a single piece of furniture goes in. Upload yours and Kansumi will read it the same way, then turn it into interior concepts.
A worked example
Take a typical listing plan for a one-bedroom flat and read it the way the extractor does.
The outer boundary is drawn with double lines. Those are your load-bearing perimeter walls, and the gap between the lines hints at their thickness. Inside, a single thinner double-line run separates the bedroom from the living space: an interior partition.
Now find the openings. Where the hallway meets the living room, the wall breaks and a quarter-circle arc sweeps into the room. That's a door, and the arc tells you which way it swings (into the living room, so don't plan a bookshelf behind it). Along the bottom edge, the wall line triples into a thin sandwich for a meter or so: a window. Count them: two doors, three windows. If Kansumi reports a different count after extraction, that's exactly the kind of thing to fix during validation. It takes one tap.
Next, the numbers. A label like "4 200" along the bedroom wall is a dimension in millimeters, 4.2 meters of real wall. Confirming that single measurement during validation calibrates every other wall, door, and window in the scene to true scale.
Finally, run the furniture sanity check: a standard double bed is about 1.4 × 2.0 m. Sketch it mentally against that 4.2 m wall. If the bed looks like it fills half the room, the scale is plausible; if it looks like a postage stamp, a dimension was misread: better to catch that on the plan than in a render.