We draw stairs on a floor plan in 4 steps:
- Specify the type of stairs on a floor plan
- Specify the floor plan we are drawing on.
- Draw the stairs on a floor plan based on the previous two steps.
- Annotate the stairs on a floor plan
By the end of this article, you’ll be able to draw all kinds of stairs on a floor plan. You will also be able to create any type of stairs based on accurate calculations that will make them safe and easy to use. Let’s get started.
01 Define the Type of Stairs on a Floor Plan
Before drawing the stairs on a floor plan, you must select the stair type.
Do you want to make a U-shaped staircase or an L-shaped one? Maybe it is a spiral staircase. Answering this question will make the next step a lot simpler. There are many different stair types.
In this section, I will explain different types of stairs in more depth, starting with the straight-run stair.
1️⃣ Straight-run stair
A straight-run stair is the simplest form of a stair. A straight-run staircase is a straight staircase that does not go left or right.
💡 Design Insight: Fire codes limit the height of a straight staircase to 12 feet (3658 millimeters) before a landing is needed. The landing depth should be equal to the stair width.
2️⃣ L-shaped stairs
An L-shaped staircase is a straight staircase that makes a left or right turn. There are three different types of L-shaped stairs:
- L-Shaped stair with landing
- L-Shaped stair with winders
- L-Shaped stair with offset winders
L-Shaped stair with landing
L-shaped stairs can have either long or short legs, and the landing can be in any direction.
L-Shaped stair with winders
We make an L-shaped stair with winders by putting treads at an angle where an L-shaped landing would be. Using winders makes the L-shaped staircase take up less space.
💡 Design insight: Winders may not comply with local codes.
L-Shaped stair with offset winders
Offset winder treads can follow the local codes because they have more generous proportions.
3️⃣ U-Shaped stair with landing
U-shaped stairs, which turn back as they go up, work best in small spaces or as part of a system for moving people between levels.
4️⃣ Spiral Stairs
Spiral stairs take up the least amount of floor space and are common in private residences. Codes do not allow spiral stairs. Therefore, spiral staircases can only be used as egress stairs in private homes with no more than five people.
💡 Design Insight: Egress Stairs is another name for the escape stairs.
5️⃣ Curved Stairs
Curved stairs are set up the same way as spiral stairs. However, if the open center diameter is large enough, the treads can be large enough to meet the legal code requirements for egress.
02 Define the floor plan
Depending on the floor plan, we draw the stairs in different ways. There are three possibilities:
- You are drawing on the floor where the stairs start.
- You are drawing on the floor where the stairs end
- You are drawing in between floors
1️⃣ The floor where the stairs start
In this case, the floor plan cut level (from 1 meter to 5 meters) passes by the stairs, and keep in mind that anything above the floor plan cut level will have dashed lines, and anything below it will have solid lines.
2️⃣ The floor where the stairs end
In this case, the floor plan cut level is above the stairs. The entire staircase will appear as solid lines.
3️⃣ In between floors
In this case, it will be a mixture of the other two options. The horizontal Plane passes , but the whole stair will look solid to indicate a cut in the floor where the stairs are on the lower level.
03 Draw the Stairs on a floor plan
Now we’ve defined our floor plan and stair type. Let’s start drawing the stairway itself. We begin by sketching the steps.
We represent each step with two parallel lines that are 5 cm apart.
- The first line is a solid line that shows the step from above.
- The second line is a dashed line that shows the stair nose. Since it is hidden, we draw it with dashed lines.
💡 Design insight: If the staircase is U-shaped, the stairs’ nose (the dashed line) must be in line at both turns.
04 Stairs annotations
Now it’s time to draw our stairway annotations. There are four types of symbols that our staircase needs.
1️⃣ Up Arrow
Draw an arrow to show which way is up.
2️⃣ Steps Numbering
Number each step, starting with one unless it’s a multi-floor staircase, in which case the numbering continues where it left off on the previous floor.
3️⃣ Stairs Dimensions
Don’t measure from the solid line. Instead, measure from one stair nose (dashed line) to the next.
4️⃣ Stairs Elevation Spot
Put an elevation spot target before and after each continuous set of steps.
Stair’s components and calculations
Before we move onto the staircase’s calculation, let’s first understand its components.
Stair Components
Before we move onto the staircase’s calculation, let’s first understand its components. Each step on a stair has a riser, a tread, and a noise.
The riser is the step’s vertical surface.
The thread is the step’s horizontal surface.
Nosing is the part of the tread that hangs off the front of the riser.
Now that we know what makes up a stair, we can move on to the calculations.
Stair Calculations
We need to do a few calculations to build the staircase right and ensure it is safe, easy to use, and has enough space.
General Rule of Thumb:
The general rule of thumb for calculating limits is as follows:
2 x Riser + 1 x Thread = (585 to 645)
If your calculations for the stairs fall within this range, you’re good to go.
Also, keep in mind the following:
- The maximum riser height is 190 mm
- The minimum thread depth is 250 mm
Tip: This is a general rule. You should always check your local codes.
Calculate the number of steps:
The floor height (from one-floor finish to the next floor finish divided by the riser’s height = the number of steps)
For example, if the floor height is 300 cm and the riser is 15 cm, the number of steps is 300/15 = 20 steps.
We learned how to draw stairs on a floor plan and the necessary calculations to make them safe. If you want to learn more about architectural floor plan symbols, check out this article.
