Understanding Stairs in a Plane: Exploring Various Staircase Configurations

Stairs are difficult to interpret in a plan, especially when we have stacked stairs or multiple stairs on top of each other. Let's quickly review four stair drawings. In this example, we have a stacked staircase, and this staircase has a filling in the middle.

We also have three different levels of a spiral staircase, which we could also call a staircase tower. We have the upper floor, an intermediate floor, and the lower floor. Let's examine the first staircase.

Where you see text, either "up" or "down, " this indicates where you can imagine standing. If you follow the arrow, you are going up the stairs or standing here and going down the stairs. In this plan, we have an up and a down, and these two points are at the same level.

If I'm at the text above, I can go up the stairs here, and if I stay at the same level and go to the text below, I can go down the stairs here. When the stairs go up, they will end in a line of rupture (cut). This line of rupture represents the section cut in the floor plan.

In this case, we have a double rupture line. The first rupture line represents the section cut for these stairs that go up. The second dashed line indicates that these stairs go down and continue below the stairs above.

Let's examine this in 3D. Remember, these two individuals are standing at the same level. We can see the stairs going up from the left and down from the right.

So, now we can see where we put our rupture line. Replace this section cut shown here in our 3D view. We can see the stairs going up from the left and the stairs going down from the right and continue below.

So, in this case, we represent this condition with a double rupture line. Now let's examine the upper floor of a zigzag staircase. This would represent a tower of stairs.

Again, when I look down, I know I am standing at this level, and the stairs go down, turn into the fill, and go down again. Notice that there are no rupture lines because there are no stairs that are covered by other stairs and no stairs that are cut by our section cut of the floor plan. This person is standing where we saw the text below, so we can see that we go down the stairs to the fill, go down again, and enter the fill of the floor below.

We can see that the fill of the floor below is covered by the fill of the floor above. This becomes more difficult to interpret when we are on an intermediate floor.

Here, we see an arrow down as in our upper floor and an arrow up, indicating that we are standing at this level, with stairs going up and down from the same fill. In this case, the stairs above end in a rupture line, indicating that they are cut in section. And the stairs below end in the rupture line because they are covered by these stairs above.

Just like in our straight stairs, we have a double rupture line. We are only showing one person here, but this person could go up the stairs here or down the stairs here. You can see where it is cut.

This will be the rupture line for the upper floor. You can also see the steps going down and how they go under the stairs above. Again, we would have our rupture lines here because these stairs are going up, and here, the stairs go down around the fill and continue down.

In our plan view, the stairs run under the stairs that go up. At the bottom of our stair tower, we only have an upward arrow. However, we know that this staircase will turn on the platform and continue upward.

We know this by looking at other floor plans for the stair tower. So, how can we have storage space below it?

The key to understanding floor plans is that they do not always represent full-height spaces. In this case, the storage room is a partial-height space below the stairs.

Let's examine that in 3D to better understand how the storage space fits under the stairs. Here, we see our standing person on the lower floor where we had the arrow up. We can see the stairs going up to the fill and continuing up from there.

We will have our separation line here. You can also see the door behind this individual. That is the door to our storage space.

Here, you can see the storage room beneath the stairs. If we cut our stairs higher, say here, we would not be able to see any of the storage space. Now, you can see the lower part of the door and the break line for the stairs.

Storage rooms beneath stairs can be challenging to understand in floor plans. Just remember that they should not be full-height spaces, especially near the break line in the floor plan.

From the top-down view, we can see the location of the break line and the storage room.

When adjusted to the floor plan, it is challenging to understand from this single drawing whether it is a partial-height or full-height space. Be sure to consult other drawings in your set for the complete picture.