Design a House

Look at the building you are in. Strip away the colour and the detail and what is left is a handful of boxes: a big one for the room, thin ones for the walls, a wedge on top for the roof, and a few box-shaped holes where the windows and the door are.

That is exactly how Tinkercad works. You drag in solid shapes, you drag in hole shapes, and you group them. A hole grouped with a solid cuts a window out of it. There is no separate "make a window" tool and there does not need to be.

The workplane is the ground

Everything sits on the workplane, the blue grid. A shape dropped on it stands at height zero. Lift a shape and it floats — which is right for a roof and wrong for a wall, and is the single commonest reason a first model will not print.

Measure in millimetres, and mean it

Tinkercad is in millimetres, and so is a 3D printer. If you decide your house is 80 mm wide then the walls, the door and the roof all have to agree with that number. Deciding it before you drag anything in is the difference between a model and a pile of boxes.

Scale: a real door is about 2 m tall. At 1:50, that is 40 mm. Pick a scale first and every other number follows from it.

By the end of this lesson you can:

• Decide a scale and write down the real measurements your model will use.
• Place, resize and position a shape on the workplane, and say what its height above the plane is.
• Use a hole and Group to cut a window or a door out of a wall.
• Line shapes up with Align instead of by eye, so the walls actually meet.
• Explain why a floating or overlapping part is a problem for a printer, and fix one.
• Export your model as an STL file ready to print.

Work at 1:50. One metre in real life is 20 mm on the workplane.

1 · Decide the numbers first

Write these down before you drag anything in.

Part	Real	At 1:50
House width	4 m	80 mm
House depth	3 m	60 mm
Wall height	2.5 m	50 mm
Wall thickness	0.2 m	4 mm
Door	0.9 × 2 m	18 × 40 mm
Window	1 × 1 m	20 × 20 mm

2 · The shell

1. Drag a Box onto the workplane.
2. Click it and type the size straight into the white boxes: 80 × 60 × 50.
3. Drag a second Box on top of the first. Make it 72 × 52 × 50 — that is 4 mm smaller on every side, which is your wall thickness.
4. Change the second box to a Hole (the striped one in the shape panel).
5. Select both — drag a rectangle around them — and press Align. Click the middle dot on each axis so the hole sits exactly in the centre.
6. Press Group. You now have four walls and a floor.

3 · The doorway

1. Drag another Box in and size it 18 × 10 × 40.
2. Make it a Hole.
3. Sit it on the workplane (height 0) and push it through the front wall.
4. Select everything, Group. The doorway is cut.

4 · A window

Same again at 20 × 10 × 20, but lift it 20 mm off the workplane so it is a window and not a second door. Group.

5 · The roof

1. Drag in a Roof shape (under Basic Shapes).
2. Size it 84 × 64 so it overhangs by 2 mm all round — real roofs do, and it hides a multitude of sins.
3. Set its height to 30, then raise it 50 mm so it sits on top of the walls, not through them.

Make it a bungalow with two rooms.

Add an interior wall 4 mm thick that splits the inside into two rooms, and put a doorway through it so you can walk from one to the other.

Keep the outside measurements exactly as they are. The only new numbers are the wall's position and the second doorway.

Hint: build the interior wall as a solid box the full inside height, then cut its doorway the same way you cut the front one.

Give it a chimney and a porch.

• A chimney: a 10 × 10 mm box standing 15 mm proud of the roof. It has to pass through the roof and stop at the ceiling, not float above it.
• A porch: a flat slab in front of the door, 30 × 20 × 4 mm, sitting on the workplane.

Both must be grouped into the house so the whole thing exports as one object. Check by clicking once — you should select all of it, not a piece.

Make the windows match.

Put a window in each of the four walls, all the same size, all at the same height above the workplane.

Doing this by dragging is slow and will not line up. Use copy (Ctrl+C, Ctrl+V), then rotate the copies 90° for the side walls, then Align to centre each one on its own wall.

Write down the height you used. Every window should report the same number in the size panel — if one differs, it will show on the print.

Design a house to a brief, not to a tutorial.

Somebody wants a model of a house with:

• a footprint no bigger than 100 × 80 mm
• at least two floors
• a staircase or a ladder connecting them, actually modelled
• a roof that overhangs on all sides
• everything printable — no floating parts, nothing thinner than 2 mm

Plan it on paper first, with the real measurements and the 1:50 versions beside them, then build it.

Think about it: a printer cannot print a part that touches nothing below it. Which of your pieces would fall? What could you change so they do not, without changing how the house looks?