Because the main goal of making an interior model of a building in Google SketchUp is to end up with accurate interior spaces, you need to work from the inside out. If your tape measure is long enough, try to figure out a way to get the major dimensions first — this means the total interior width and length of the inside of your building. You may not be able to, but do your best. After that, just work your way around, using basic arithmetic and logic to figure out things.

Before you start drawing an interior outline in SketchUp make a paper drawing. The drawing helps you know what you need to draw so you can focus all your concentration for drafting on the computer.

From this paper drawing, here’s how you draw a basic interior outline of this house:

1. Switch to a 2D overhead view.

2. Using the Line tool, draw an edge 17 feet long, representing the eastern wall of the house.

To draw it, click once to start the edge, move the cursor up until you see the green linear inference (indicating that you’re drawing parallel to the green axis), and click again to end the line. To make the edge 17 feet long, type 17' and then press Enter — the line resizes itself automatically to be exactly 17 feet in length. If you wanted to, you could use the Tape Measure to double-check what you did.

3. Draw an edge 11 feet 10 inches long, starting at the end of the first edge, heading to the right in the red direction.

To do this, do exactly what you did to draw the first edge, except that you move parallel to the red axis this time, type 11'10 and then press Enter.

4. Keep going all the way around the house, until you get back to where you started.

If you make a mistake, either use the Eraser to get rid of edges you’re unhappy with or choose Edit, Undo to go back a step or two.

5. If all your measurements don’t add up, adjust things so that they do — a few extra inches here and there never killed anyone, after all.

After you complete the outline (forming a closed loop of edges that were all on the same plane), a face automatically appears. Now you have a total of 11 edges and 1 face.

When you draft in 2D, whatever you do, don’t use the Orbit tool. Because you work in 2D, you need only to use Zoom and Pan to navigate around your drawing.

If you get lost, and no amount of zooming and panning gets you back to a view of your floorplan, choose Camera, Zoom Extents — think of it as an emergency lever you can pull to fill your modeling window with your geometry.