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How Wide Should a Staircase Be? (Read This First!)

Building a standard staircase in the right width, depth and riser height entails critical measurement and calculations. You will have to do a thorough research in order to build the right staircase for your home, workspace or other establishments.

We have designed this article to help you with just that. We will walk you through the factors of measurements that you will need to keep in mind.

We will discuss how wide different kinds of staircases should be. We will also provide you a thorough insight into how you can keep your stairs up to code. So without further ado, let’s read ahead to learn more about it.

How wide should a staircase be?

A staircase should be at least 3 feet. This is the minimum width requirement in any staircase. You can of course expand it as much as you’d like, depending on the particular needs of your establishment. Note that you need to reach a minimum of 36 inches width requirement for the entire staircase.

There are several factors involved in determining the width of a staircase. In the following section, let’s take a look at different kinds of staircase and their width requirement that you should follow:

Straight staircase:

A straight staircase should be at least 36 inches in width. This width requirement extends from above the handrail.

So you will need to build a handrail that falls within the width range of 34 to 38 inches above the stairs.

Quarter landing staircase:

Quarter landing staircase is also known as L-shaped staircase. These staircases have the same width requirement as a straight staircase.

That is to say, you will need to maintain a minimum of 3 feet width in this case. And above the handrail, you will need to keep a minimum of 36 inches width.

In addition, underneath the handrail, you will need to keep at least 27 to 31.5 inches of width. This will depend on whether you’re opting for a single or double handrail.

Half landing staircase:

The half-landing staircase also has the same width requirement as the straight staircase. You will need to keep at least 36 inches width above the handrail.

And under the handrail, you will need to keep a width between 27 to 31 inches, depending on the type of handrail you’re going for.

Bifurcated staircase:

The bifurcated staircase also has similar width requirements as mentioned above.

A minimum width of 36 inches above the handrail is required in this case. And you will need to keep the staircase about 3 feet wide.

Curved staircase:

the width requirement is a lot different in case of a curved staircase.

In case of a curved staircase, there is an International Building Code compliant that requires you to keep at least a diameter of at least 5 inches around the staircase.

Note that the standard diameter range in this case is up to 6 inches width. But you can of course make it wider depending on the purpose and capacity of the staircase that you’re opting for.

Spiral staircase:

Spiral staircases have a similar width requirement. You will need to maintain a width requirement of at least 5 inches diameter when you’re working on a spiral case.

This is a requirement set by the International Building Code. While the standard width in case of a spiral staircase is 6 inches diameter, you can make it wider as per your need.

Deck staircase:

The deck staircases should be at least 3 feet in width. But you can make it much wider depending on the traffic that you’re expecting.

Residential staircase:

Residential staircases should have a minimum width of 3 feet or more. You can make it wider if you’re expecting a large traffic.

Foyer staircase:

A foyer staircase should have a minimum width of 36 inches and more.

How wide should a staircase runner be? How wide should a stair tread be?

Maintaining an appropriate width for your staircase runner is important because it is where you walk on. You will need to feel secure in the staircase runner.

The staircase runner should be adequately wide so that you don’t feel it’s too small for you, nor do you want to feel that it’s too large for the staircase.

If the width of your staircase is 3 feet, then we will suggest that you build a staircase runner that has a width of 27 inches. And the stair tread should be 36 inches in width. This is an appropriate width for the staircase runner.

A staircase runner and tread of this width will offer you a feeling of security. You will not feel like you’re walking on a narrow strip. Neither will you feel that the runner and tread is overpowering the staircase. So it stands in fine line pretty nicely.

What is the minimum width of residential stairs?

Different kinds of establishments have different requirements for staircase width. But in general, a residential staircase should be at least 3 feet or more.

Also note that a standard building code requires you to build a staircase that has at least a width of 36 inches, that is measured from top of the handrail.

Also note that the minimum width of the staircase extends to a minimum of 6 to 8 inches on top of the line that is placed before the stair treads.

In addition, the staircase should have a width of 27 to 31.5 inches under the handrails. Here the upper limit is for when you will have a double handrail.

How wide should a stair landing be?

A stair landing should be about 36 inches or wider. This is the minimum requirement set by the International Building Code.

Since the minimum requirement for most staircases is 36 inches, the stair landing will have to be at least that wide. The stair landing will need to be wider than the staircase.

Often, the stair landing is made a couple of inches wider than the staircase in order to be more comfortable. You can make it even wider if you’re expecting a large traffic.

A wider staircase landing may also provide a good architectural interest. They enhance the aesthetic value of your building. This will make both the building and the staircase much more pleasing visually.

In addition, it will further add to the comfort of the traffic. So you might want to factor that in as well.

Does stair width include a handrail?

Yes, stair width includes a handrail. The International Building Code allows the handrails to project as much as 4 and a half inches into the required width of the staircase, including the aisles, ramps and stairways, on each side of the staircase.

Staircase will need a handrail on both sides. Every stairway will need to be more than 88 inches in width along with a handrail on each side.

Including the handrail, a staircase will need to have a width of at least 44 inches. If you’re expecting an occupant load of 50 people, then you will need to have a staircase of at least 36 inches, handrail excluded.

How to keep your stairs up to code?

It is quite challenging to keep your stairs up to code, as all homeowners and builders will agree. But you will need to maintain it anyway.

Aside from legal reasons, the staircase codes set by the International Building Code help you build a rather safe stairway for the occupants, whether it is a residential or commercial building.

In this section, we will discuss how you can keep your stairs up to code:

Maintain the staircase width:

The first step in maintaining the code is to follow the proper requirements in case of the staircase width. This width refers to the horizontal or side-to-side width of the staircase.

It should be at least 36 inches, given that you’re expecting a traffic of at least 50 people. If the expected traffic is higher, then you should build a wider staircase.

Staircase landing:

You need to have a staircase landing, both at the top and bottom of the staircase. Note that the width of the landing should be at least as wide as the staircase itself.

Staircase lighting:

This section is often overlooked, but you will need to pay attention to the lighting of the staircase if you’re trying to keep your staircase up to code.

Make sure that your staircase has a lighting of at least 11 lux for each landing. In addition, install a wall switch for every six risers.

Final Thoughts

The minimum width requirement varies depending on the type of staircase that you’re building. The International Building Code suggests that for a straight staircase, you will need to maintain a width of at least 36 inches above the handrail. In case of a spiral staircase, it is 6 inches in diameter.