A floor plan is a language: standardized symbols that pack walls, doors, windows, stairs and fixtures into a single scaled drawing. Once you can read them, any plan — an estate agent's brochure, a building permit drawing, a builder's sketch — becomes unambiguous. This reference covers the symbols you'll actually meet. Two things to know first: everything is drawn to scale as seen from above, with the building sliced horizontally about a metre above the floor — which is why windows appear inside walls and doors appear as gaps.
Walls
Walls are the skeleton of the plan, drawn as two parallel lines with the real wall thickness between them. Exterior walls are thicker (typically 250–400 mm); interior partitions thinner (about 100–150 mm). On printed plans the space between the lines is often filled or hatched — the fill is called poché.
Exterior wall
Thick double line, often filled. Carries the structure and insulation.
Interior partition
Thinner double line dividing rooms.
Doors
A door is a gap in the wall plus a quarter-circle: the straight line is the door leaf, the arc is the space it sweeps when opening. The arc matters — it shows which side the hinges are on, which way the door opens, and how much floor it needs to stay clear.
Single door
Leaf shown open at 90°, arc shows the swing. Hinge is where leaf meets wall.
Double door
Two leaves, two arcs meeting in the middle.
Sliding door
A panel drawn beside the opening with an arrow — no swing arc, because it needs no clear floor.
Windows
A window is drawn inside the wall as parallel thin lines across the opening — usually three: the two faces of the wall and the glazing line between them. Unlike doors, windows don't break the wall's outline; the thin lines tell you it's glass, not a gap.
Window
Thin triple line within the wall thickness.
Stairs
Stairs appear as a row of parallel lines — one per tread — with a walk line showing the direction of travel, usually marked "UP" from the level you're standing on. A diagonal break line means the stair continues beyond what this floor's plan shows.
Staircase (up)
Treads, walk line with arrow, "UP" label.
Bathroom Fixtures
Sanitary fixtures are drawn as simplified top-down outlines at their real size — that's the point of showing them: proving the room actually fits a toilet, a basin and a shower with usable space between them.
Toilet
Cistern against the wall, bowl in front.
Basin / sink
Oval or rectangle with a tap mark on the wall side.
Shower
Square tray with a diagonal cross.
Bathtub
Rounded rectangle with the inner rim drawn, drain at one end.
Kitchen
Kitchens are drawn as a run of 600 mm-deep counter rectangles along the wall, with the appliances marked inside the run. The symbols confirm the working sequence — storage, sink, prep, cooking — and that doors and drawers can open.
Counter run
Rectangles, 600 mm deep, backs to the wall.
Kitchen sink
One or two bowls inside the counter, tap on the wall side.
Stove / cooktop
Square with four burner circles.
Fridge
Deep rectangle, often marked with a diagonal or "REF".
Furniture
Furniture symbols are simple outlines at real dimensions. They're optional on technical drawings but essential on layout plans — a bedroom only "works" if a real 1600 × 2000 mm bed fits with walking space around it.
Bed
Rectangle with pillow and a folded-corner blanket line.
Sofa
Seat with back and armrests drawn as thin bands.
Dining table & chairs
Table outline with a square per chair.
Wardrobe
Rectangle with a centre line; a dashed line marks the hanging rod.
Dimensions & Annotations
The marks that make a plan usable on site: dimension chains along the walls, room names with floor areas, and a north arrow for orientation. If a plan has no dimensions, treat every measurement you take from it with a ruler as an estimate.
Dimension
Extension lines, a dimension line with tick marks, and the length in mm.
Room label & area
Room name with the net floor area in m², measured to the inner wall faces.
North arrow
Shows the plan's orientation — useful for judging daylight.
Reading the Line Weights
Professional plans also speak through line thickness: the heaviest lines are cut structure (walls), medium lines are fixed objects seen from above (fixtures, stairs, built-ins), and the lightest or dashed lines are overhead elements (upper cabinets, roof lines) or movable furniture. If a line looks faint, it usually means "this is above the cut plane or optional."
Drawing These Symbols Yourself
On paper, symbols take practice — door arcs want a compass, and window triple-lines want a steady hand. In Gridsnap they draw themselves: place a door and the swing arc appears with the correct hinge side; windows render as proper triple-lines inside the wall; stairs come with treads and walk line; every fixture and furniture symbol is a parametric object at real size. Reading plans is a skill — drawing one no longer needs to be. And if you have an existing drawing full of these symbols, you can trace it into an editable plan.