Thick walls, thin furniture, dashed hidden edges — the visual grammar of drawings.
Look at any professional floor plan and squint. Even from across the room, before you can read a single word, the drawing sorts itself: heavy dark outlines here, faint light lines there, dashes in a few places. That is not decoration — it is a language, and this lesson teaches you to write it.
The grammar in one table
Line
Means
Example
Thick
Something cut through — solid, structural
Walls in a floor plan
Thin
Something you see but did not cut
Furniture, fittings, tiles
Dashed
Something hidden, or above the cut
A high shelf, a hidden edge
Dash-dot
The centreline of something
Centre of a column or hole
Where do thick and thin come from? Convention: a floor plan is an imaginary horizontal slice through the building, about a metre above the floor. Whatever that knife cuts through (walls) draws thick. Whatever sits below the knife, merely seen from above (furniture, floors), draws thin. Whatever hangs above the knife or hides inside something draws dashed. Once you know the slice, the grammar stops being arbitrary.
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