Understanding Floor Plan Dimensions and Scale in Architectural Drawings

Let's start by looking at the plan of the first floor of the residence. Again, in the lower right corner of the sheet is the title block. You can see that we are on page A1-0.

The graphic area for the house is located here. You will also notice that there is a graphic scale down in that section. So let's get closer to that area.

You can see that it shows 0,1 foot, 2 feet, 3,4 to 8 feet, and there are smaller increments there as well. The drawing is scaled at 1/4 inch equals 1 foot.

If you were to print this drawing independently, you could always take the graphic scale and copy it. You could place it against something to confirm that it is approximately accurate. The general rule is that you never take the scale out of the plans.

If you have a question, you get in touch with the Architect or the Designer and say, “What is the dimension from here to here?” Do not measure it yourself. But the graphic scale tends to be a very good way to let people estimate information approximately. Now, as we begin to develop the building, you will notice many similarities with what we have covered before.

In the sense that you have the building, and you have dimensions that surround the building. Now let me tell you about some of the procedures for how dimensions normally work. You can see that in this section, we have three rows of dimensions.

The first row is typically a general dimension. This indicates that it is approximately 80 feet 7 inches. The dimension line extends to the inclined bar here.

So the initial dimension goes down to the outside face of the frame of the construction. Now notice that some of the walls are dark and some have fine linework in them. The dark walls represent the wood that forms the frame of the building.

The shaded areas on the outside represent the brick cladding. So again, we are showing that the dimension of 80 feet 7 inches goes from the outside frame on the left to the corresponding dimension line. I'm just following down here.

To the outside frame here. So the first row is typically general. The second row is typically for the major segments of the building.

What we are saying is that there are 7 feet from the outside of the frame in this corner to the outside of the frame in this corner. There are 48 feet 9 inches from the outside corner here to the outside corner of the porch to the right. There are also 4 feet 10 inches from the outside corner of the porch to the outside corner of the building.

The next row is used to indicate the measurements from face of wall to face of wall. You will see that it measures 5 feet 7 1/2 inches from the outside left face of the frame here to the right face of the frame here. Now, this next dimension line is not entirely solid.

It is what we would call a centerline. This shows that there are 5 feet 8 inches from this corner of the frame to the centerline of the window, and 5 feet 7 1/2 inches from the centerline of the window to this other corner of the frame.

You can see a note here—a number inside a hexagon—that is the symbol of the window number. So what is happening is that this window in this main room is window number 5. And when we reference the window schedule, you will learn more about this specific window, number 5. Here in the bathroom to the left, you can see that the symbol indicates number 4. If I pan, you can see that window 4 is 4 feet 3 inches—the center of the window is 4 feet 3 inches from the outside corner of the frame to the centerline of the window. Well, let's continue with this section.

We had 5 feet 7 1/2 inches from the outside corner to the edge of the wall, 5 feet 8 inches to the centerline of the window. I see the symbol of the window, and I also see a keynote.

Then, once again, I continue my dimensions to the corners of the frame. And again, you can notice here that it is 8 feet 1 inch from this corner to the centerline of the column here. Then 4 feet 5 inches from the centerline of the column to the centerline of the door, and so on and so forth.

So again, you are seeing consistency in the drawings. If I look here to the left, again I have my chain of general dimensions. I am showing a dimension for this exit—it is about 2 feet 6 inches from this corner to this corner down here.

Then again, you see larger gaps in the building, with 2 feet 6 inches, 29 feet 2 inches, 11 feet 5 inches, and so on. The third row includes interior walls and also shows dimensions to the centerlines of windows. All windows have window symbol numbers on them.

And again, it is consistent throughout the building.