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. (For the words that go with the drawings — jamb, mullion, riser, soffit — see the architect's glossary; for reading a whole listing plan as a buyer, start with how to read a floor plan.)
Three families are deep enough to have a page of their own, each variant drawn twice — the convention, and how a CAD editor actually renders it: door symbols, window symbols and staircase symbols.
The floor plan symbol legend
Nine families of symbol, the mark each one makes, and what it means. Every row jumps to that section.
| Symbol | Family | What it means |
|---|---|---|
| Walls | Two parallel lines the real thickness apart, often filled in — the part of the building the drawing cut through. | |
| Doors | A gap in the wall with a leaf and a quarter-circle arc; no arc means it does not swing. | |
| Windows | Thin parallel lines across the opening, inside the wall thickness — glass, not a gap. | |
| Stairs | A run of parallel treads with a walk line and an arrow, labelled UP from the floor you are on. | |
| Roof Lines | Dashed lines above the cut: the eaves outline, and the ridge, hips and valleys inside it. | |
| Bathroom Fixtures | Simplified top-down outlines at real size — there to prove the room fits them. | |
| Kitchen | A 600 mm-deep run of counter with the sink, hob and fridge marked inside it. | |
| Furniture | Plain outlines at true dimensions; optional on a technical drawing, essential on a layout. | |
| Dimensions & Annotations | Dimension chains, room names with their area, and the north arrow. |
What do wall symbols look like on a floor plan?
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.
What does a door symbol look like?
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.
Named variants: Hinged · Double · Double-acting · Sliding · Bypass pair · Pocket · Bifold · Cased opening · Garage — each one drawn out, beside how a CAD editor renders it, on Door symbols in full.
What does a window symbol look like?
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.
Named variants: Fixed, casement & sash · Sliding · Mullions & transoms · Coupled pairs · Bay & bow — each one drawn out, beside how a CAD editor renders it, on Window symbols in full.
What does a staircase symbol look like?
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.
Named variants: Straight flight · Break line · L-shaped · U-shaped · Winders · Spiral — each one drawn out, beside how a CAD editor renders it, on Staircase symbols in full.
What do roof lines mean on a floor plan?
The roof sits above the cut plane, so on a floor plan its lines are drawn dashed — they show something overhead, not something you could walk into. The outline is the eaves (the roof edge including its overhang), and the lines inside it name themselves by direction: a ridge is the horizontal top, hips slope down an outside corner, valleys sit in an inside corner where two roofs meet. A small arrow points down the slope.
Ridge & eaves
Dashed eaves outline past the walls; the ridge runs along the middle where the two slopes meet.
Hip roof
Hips run diagonally from each corner to the shortened ridge — slopes on all four sides.
Valley
Where two roofs cross, the internal crease is a valley — rainwater runs along it, which is why gutters care.
Slope arrow & skylight
The arrow points down the fall; a skylight is a rectangle with a diagonal cross set on the slope.
What are the bathroom fixture symbols?
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.
What are the kitchen symbols on a plan?
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".
How is furniture drawn on a floor plan?
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.
What do the dimensions and annotations mean?
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.