Craft Quantities
Plan & Takeoffs

Design: Construction Canvas

Draw the walls, get every material

A to-scale plan editor that turns each wall you draw into a list of what to order: studs, plates, sheathing, wrap, insulation, cladding, the flashing and casing round every opening. Quantities, never prices, worked by the site’s own takeoffs.
  • To scaleTyped lengths, snapping
  • Mouse, touch, penOr the keyboard alone
  • SVG, DXF, PDFFrom the model

Prefer a form? Use the House Estimator: give a rectangular footprint, the storeys and the openings, and get the same list without drawing a line.

Plan of a one-storey house with its walls, windows and doors, the drawing the canvas opens on.39 ft11.89 m30 ft9.14 m
The house the canvas opens on: draw over it, or start a blank drawing.
Plan of a one-storey house with its walls, windows and doors, the drawing the canvas opens on.39.37 ft12 m29.53 ft9 m
The house the canvas opens on: draw over it, or start a blank drawing.

What happens when you draw a wall

Each wall is stored as two points on its centre line and a wall type, in whole millimetres. Its outside and inside faces are worked out from its neighbours, so a corner is bought once and a partition stops at the face of the wall it meets. Doors and windows live on their wall and come off every face they pass through, and once off the wall’s core.

Studs are counted wall by wall, because a stud count rounds up along one straight run. Sheathing, wrap, batts and cladding are counted once for all the walls of one type, height and storey, so the rounding happens once. Change a wall type from 2×4 to 2×6 and every wall built as it thickens on the plan and the rows change together.

Nothing is sent anywhere while you draw. The list is worked in your browser by the same takeoffs that run on the site’s job pages, and each row says which calculator worked it.

How to draw

  1. Open the canvas. Press Open the canvas. It starts on the house the estimator opens on, or on your project's own drawing if it has one; Start a blank drawing clears the paper.
  2. Draw the walls. Press W and click each corner, or type a length and press Enter after each one: 5200 is 5.2 m, 17'6 is seventeen and a half feet. An arrow key turns the next wall.
  3. Put in the doors and windows. Press O for a door, O again for a window, and click the wall it belongs in. Its size and its place along the wall are in Properties.
  4. Change what you drew. Select a wall and drag its end, or type a new length in Properties. M moves, C copies, R rotates and F mirrors the selection; Ctrl+Z steps back.
  5. Send the list. The list under the drawing follows every change. Add to My Project puts it on your project's lines, where your own rates go.

On a touch screen a point is placed when you lift your finger, two fingers pan and zoom, and a long press opens the menu; a right click does the same with a mouse. Snapping finds wall ends, middles, crossings, the square from where you started and alignments with other corners; S turns it off, Shift keeps a wall square.

The keys

V
Select and edit
W
Draw walls
O
Place a door, then a window (press again to switch)
H
Pan (or hold Space, or drag with the middle button)
N
Name a room: click inside a closed loop of walls
T
Draw a straight stair: its foot, then its head (it climbs to the next level up)
P
Draw a roof: click inside the outside walls, or click its corners and press Enter
J
Draw a floor: inside the walls, or its corners (its joists counted)
U
Draw a slab: inside the walls, or its corners
L
Place a column
B
Draw a beam: its two ends
I
Place a pad or a pier
Q
Place a service point: an outlet, a light, a fixture (choose it in Services)
Y
Draw a cable, pipe or duct route: its corners, then Enter
Z
Draw a driveway, patio, deck or bed (its corners), or a fence or retaining wall (its path; choose it in Services and site)
K
Calibrate the plan under the drawing: two ends of a known line, then its length
Enter
Place the point, draw the typed length, or finish the run
Esc
Cancel what is being drawn, then clear the selection
Delete or E
Erase the selection
Ctrl+Z
Undo
Ctrl+Shift+Z or Ctrl+Y
Redo
Ctrl+A
Select everything on the level
Ctrl+D
Duplicate the selection one grid step across
M
Move the selection: the base point, then where it goes (Enter takes the centre; type a length)
C
Copy the selection, as many times as you click, until Esc
R
Rotate the selection: the centre, then the angle (15° steps; type degrees)
F
Mirror the selection: two points of the mirror line (Enter twice flips it left to right)
+
Zoom in
-
Zoom out
0
Fit the drawing
G
Grid on or off
S
Snapping on or off
Tab
While drawing: the next snap candidate
?
This list

What it counts, and from which takeoffs

Openings, and what the house around them takes

Start from a worked house

Each example has an Open in the canvas button: it copies the house into a new project and opens it here, so your own drawing is never touched.

Files, limits and what comes next

  • SVG, DXF and PDF are written from the drawing’s own geometry: a DXF opens in millimetres on its CQ-* layers, a PDF states the scale it is printed at.
  • One storey is drawn at a time. Slabs, footings and roofs come from the house the drawing started from; drawn roofs, rooms and a traced photo or PDF underlay are later stages.
  • Before ordering, read how a whole house is taken off and how to choose a framed wall build-up.

Questions

What is the Construction Canvas?
A plan editor for the shell of a house: you draw exterior walls and partitions to scale, set doors and windows into them, and the page lists every material those walls take. The figures come from the same whole-job takeoffs the House Estimator runs, wall by wall, with each opening taken off the faces it passes through.
How is it different from the House Estimator?
The estimator builds a rectangular house from a few figures in a form. The canvas lets you draw any plan, an L, a T, a wing, an odd partition, and edit it wall by wall. Both keep one drawing per project, so a house started in the form can be finished on the canvas; once it has been drawn, the form leaves it alone.
Can I use it without a mouse?
Yes. Tab to the drawing, press W and Enter to start at the cursor, then an arrow and a length, Enter, for each wall. Every object is also in the Objects list, where the arrow keys move through them, and every drag has a box to type in under Properties. A short summary of each change is read out to a screen reader.
Does it work on a phone or a tablet?
It does: one finger draws, a point is placed when you lift it, two fingers pan and zoom, and a long press opens the menu. With a pen, touches from your palm are ignored while the pen is down. It is designed for a tablet or a desktop screen; on a phone it is best for checking and small changes.
What files can I take away?
The plan as SVG (opens to scale in a browser or Inkscape), as DXF for a CAD program (millimetres, layers named CQ-WALL, CQ-OPENING and so on) and as a one-page PDF at a stated scale. All three are drawn from the model, not copied from the screen.
Is anything uploaded?
No. The drawing is kept in this browser, in the same store as your projects, and goes elsewhere only if you back up, use Save with Google, or download a file. The page works offline once it has loaded.
Does it check the structure?
No. It counts materials for what you draw; it never sizes a stud, a lintel, a footing or a roof. Spans, loads and code checks belong to an engineer or your building official, and the site's own check calculators are linked from the rows they concern.