Floor plan and building layout

Draw walls with ▬ Wall (W): click (on a phone: touch, aim, lift) at each corner. Choose Exterior or Interior and the thickness. While drawing, type a length and press Enter — 12'6", 12' 6 1/2", 12ft 6in, 3.8m, 380cm, 3800mm, or a bare number in metres (metric) or feet (imperial); add @90 for an angle in degrees. Click the start point to close a loop; Enter, a double-click or ✓ Finish ends the wall. Esc cancels.

Snapping (the chips beside the length box): the grid, wall ends, midpoints, the perpendicular foot on a wall, any point on a wall, and 45° steps; hold Shift to lock to 0/45/90°. A green mark shows what the point snapped to. A wall that ends on another wall makes a T-junction (the other wall is split there), and walls that cross split each other, so the joins are drawn clean and rooms close.

Edit with ↖ Select (V): click to select, drag a wall to move it (the walls joined to it stretch), drag a wall’s end (select the wall first) onto another end or wall to join them, drag a door along its wall. The Selection panel edits thickness, length, kind and size; Split in the middle, Delete (or the Delete key). Undo / redo: ↶ ↷, Ctrl+Z, Ctrl+Shift+Z. Drag empty space to pan; scroll or pinch to zoom.

Doors and windows (D, N): click on a wall. Doors are hinged (with the swing arc), double, sliding, a plain opening or a garage door; the side of the wall you click is the side the door opens to, and H flips the hinge. Windows have a sill and head height (used in 3D).

Rooms are found automatically wherever walls enclose a space; each shows its floor area inside the walls. Double-click a room (or select it) to name it. ⬠ Room draws a room by hand where walls are not closed.

Stairs (S): click the foot, then the top. The number of risers follows from the floor height (risers ≤ 190 mm and the 2R + G ≈ 600–630 mm comfort rule — a rule of thumb; your building code decides). The floor above shows the flight as a dashed outline so you can line the stairwell up.

Dimensions (M) — two points and the offset; automatic dimensions (Show and snap) measure each exterior face. Labels (T). Furniture (U): beds, sofas, tables, kitchen units and appliances, bathroom fittings, a car and a workbench at typical sizes (change them in Selection); R rotates.

Floors: add a floor above (blank, with this floor’s outline, or a duplicate), rename, set the floor-to-floor height, reorder, delete. The floor below shows faintly while you draw.

Trace a plan image: under Plan image and tracing, import a PNG, JPG or a PDF (page 1, read by pdf.js) — or drop it on the drawing. Then 📏 Calibrate: click two points a known distance apart (a long wall) and type the distance. ⟂ Straighten rotates the image so a line you click becomes level; set the opacity, lock it, or nudge it into place. Trace over it with the wall tool, or press 🔍 Detect walls: a background worker finds dark wall strokes (horizontal and vertical runs, and diagonal ones by Sobel edges and a Hough transform paired with the parallel edge on the far side), merges pieces into long lines, joins them at corners and T-junctions and estimates each wall’s thickness. Suggestions show dashed orange: click one to accept or reject it, double-click to accept, or Accept all. Sensitivity trades missed walls for false ones (high sensitivity also takes thin lines).

3D: the Plan / 3D switch extrudes the walls with their door and window openings, glazing, floor slabs, stairs and furniture blocks, floors stacked; drag to orbit, scroll to zoom.

Areas: below the plan, every room’s floor area, each floor’s net and gross area (to the outside of the exterior walls), wall lengths, and the totals.

Export: SVG and PNG of the floor (SVG is scale-true, in millimetres), DXF of the whole building (AutoCAD R12, a layer set per floor — GROUND_FLOOR-WALLS, -OPENINGS, -STAIRS, -ROOMS, -FURNITURE, -DIMS, -TEXT — in millimetres, or inches for an imperial plan), and JSON to keep a copy or move a plan to another browser. Print to scale at 1:50, 1:100, 1/4" = 1'-0", 1/8" = 1'-0" … on A4–A2, Letter or Tabloid, with a scale bar; print at 100 % (actual size) so it measures true.

Projects… lists the plans saved in this browser (newest first), with new, duplicate and delete, and the examples. The units switch (m / ft-in) changes how the plan is shown and typed.

⛶ Full screen (or F) gives the drawing the whole screen; ◫ Panels hides the side panel; Escape leaves.