Creating Layers and Starting to Draw in AutoCAD: Offset and Trim

Ufuk ŞEN

November 3, 2026Updated: November 9, 20265 min read1

The AutoCAD Offset and Trim commands are the two tools you’ll use most when drawing a floor plan. In this lesson we first create wall, window and door layers on a blank sheet. Then we draw a small room and build the wall thickness, window opening and door swing step by step. It’s a hands-on lesson for anyone starting to draw in AutoCAD for the first time.

Creating Layers and Starting to Draw in AutoCAD: Offset and Trim

We recorded this lesson in 2013 with the classic AutoCAD interface. The icons have moved in newer versions. But the command names and how they work have stayed the same. (The video is in Turkish; this guide walks through the key steps in English.)

In this video

creating a new layer and giving it a color,
drawing a room to exact dimensions with the Line command,
setting wall thickness and the window gap with Offset,
extending lines with Extend and cutting off the excess with Trim,
fixing layers with Match Properties,
drawing a door swing arc with Circle and Trim.

Create the layers first

We open the Layer window from the Format menu. When you click the new layer icon at the top left, a row called Layer1 appears. We rename it to “duvar” (wall) and pick a color from the color box. We add the window and door layers the same way. In the video we gave the window color number 140 and the door red.

We recommend setting up layers before you draw. You can change layers after the drawing grows, but things get messy. These three layers are enough to start. You can add new ones later if needed.

Drawing the room with the Line command

First we make the wall layer active. In the Line command, a left click starts the line. A right click or Esc ends the command. Make this a habit. With Ortho on, we move the mouse in one direction, type 400 on the keyboard and press Enter. Then we draw the other sides the same way and close the room.

Wall thickness with AutoCAD Offset and Trim

Now we give the room a 20 cm wall thickness. When you choose the Offset command, the command line at the bottom asks for a distance. We type 20 and press Enter. Then we select the line and point the mouse inward. That creates a parallel line 20 cm inside. If you point the mouse outward, the offset works outward.

The midpoint for the window opening

We want to place the window exactly in the middle of the wall. Holding Shift and right-clicking brings up the object snap (osnap) menu. From there we choose Midpoint. Then we draw a reference line up from the middle of the wall. Next we copy this line 80 cm to the right and 80 cm to the left with Offset. The result is a window opening 160 cm wide.

Extend and Trim together

The new lines don’t reach the outer wall. So we open the Extend command and first select the outer line as the boundary. After right-clicking, we click the lines we want to extend one by one. Then we switch to the Trim command. We select the whole drawing from right to left and right-click. Then we click the pieces we want to remove one by one. We delete the remaining reference line with Delete.

Window detail with AutoCAD Offset and Trim

Now we switch to the window layer and draw the window lines with the Endpoint snap. We use Midpoint for the middle mullion. With Offset we use 1.5 cm for the mullion thickness and 5 cm for the frame. We clean up the extra ends with Trim again.

Along the way we notice that one line is the wrong color. That’s because we drew it while the wall layer was active. To fix it we use the Match Properties command. First we select the object on the correct layer, then the object we want to fix. That way the properties pass from one object to the other.

Opening a door with AutoCAD Offset and Trim

In the eleventh minute of the video we open a 90 cm wide door. First we draw a reference line from the corner. With Offset we set a 10 cm door return, then the 90 cm door width. We cut the wall piece in between with Trim. We move the remaining pieces to the wall layer with Match Properties.

Then we make the door layer active and draw the door leaf with Line. To show the swing direction, we draw a circle (Circle) with a radius of 90. When we trim off the extra part of the circle, the door’s swing arc remains. In short, we built the whole logic of a small room with these few commands.

You’ll find the previous lesson on layer logic and the whole series on our AutoCAD basics page. For an overview of the topic, read our AutoCAD tutorial article. If you later want to take this plan into 3D, our plan to 3D model article is the natural next step. For the current version, see the Autodesk AutoCAD page.

Summary

With the AutoCAD Offset and Trim commands, you draw walls, windows and doors in a few minutes. Set up the layers first, then select the active layer and draw. Make parallel lines with Offset, extend with Extend and cut with Trim. Fix a line on the wrong layer with Match Properties.