Stair Railing Building Code Summarized

Interior Stair Railing

Janja Milosevic / EyeEm / Getty

When remodeling homes, do-it-yourselfers often keep a loose watch on building code but rarely thumb through the codebook at every available chance. Common home projects such as painting, floorcovering installation, and tiling rarely touch upon building code. So, following logic can go a long way with simple home improvement projects. But other projects, especially those that are related to safety, such as electrical and plumbing, are strictly by-the-book. ​Staircase railing heights and widths work the same way. Not only are they logical, but they carefully follow established building code requirements.

When you start looking at the stairway code regarding handrails, you begin to see the logic behind it. Code, despite the way it may seem at first, is not an arbitrary thing. For instance, the requirement that handrails be continuous all the way down is common sense. Switching from one rail to another may be just the thing that causes you to lose concentration and fall, mid-switch. Staircase code helps you avoid this.


Watch Now: Understanding Stair Railing Codes for Your Home

IRC Stair Railing Code

The International Residential Code for One-and Two-Family Dwellings (IRC) and the International Building Code (IBC) address staircase railings. These are two "model" codes and are offered as suggested guidelines for local code authorities to follow at their discretion. However, because communities often adopt and adapt the model code, it is necessary to check with your local building code authority (usually the city building department) for code that pertains to your community. Staircase railing and guard construction, for both new homes and remodeled homes, may also trigger permit requirements.

Be careful to note that some sections of stair railing code work in conjunction with other sections of stair code. For example, the minimum hand clearance between the railing and the wall that it is mounted on is 1 1/2 inches. Yet, if the railing is pushed out too far, there is the risk of violating another section of code that provides for 27 inches of walking width between the two railings of a double-railing staircase.

illustration of stair railing codes for homes
Illustration: © The Spruce, 2018

Stair Railing vs. Stair Guards

One word on terminology: Stair railing and stair guards, though they may sound like the same thing, are different. Stair railing runs on the stair incline, up and down. By contrast, stair guards run horizontally along a flat area, with a drop on the other side. Stair guards do not protect stairs but are often used in conjunction with stairs, as with stair landings or elevated walking areas leading to stairs.

Handrail Height: 34 to 38 Inches

Handrail height is the height of the handrail in relation to the stairs.

Handrail height on the stairs should be no less than 34 inches and no greater than 38 inches. The way this is measured is to begin at the leading edge of the stair nosing and run an imaginary vertical line upward until it reaches the top of the railing. The same measurement applies to all of the stair nosings, thus resulting in a railing that is parallel to the stairs.

Measuring at a different part of the stair tread than the nosing or at a different part of the handrail than the top will give you an inaccurate measurement and might result in a code violation.

There are some exceptions where handrails can be higher than 38 inches, such as continuous transitions between flights or transitions from a handrail to a guard.

Maximum Projection of Railing From Wall: 4 1/2 Inches

Projection from the wall describes how far the handrail is away from the wall that it is mounted on.

The edge of the handrail that is farthest away from the wall it is mounted on should not project more than 4 1/2 inches from the wall.

Railing that projects farther than this will crowd the walking path, especially when there is a railing at the other side of he stairs, limiting the walking space.

Minimum Hand Clearance From Wall: 1 1/2 Inches

Minimum hand clearance means the distance between the handrail and the wall. In other words, this is the area where your hand goes.

Provide at least 1 1/2 inches of clearance between the wall and the railing for easy grasping by the hand. This clearance is represented by a line that extends from the wall to the nearest part of the handrail.

Purchasing code-compliant handrail brackets will guarantee that you maintain the perfect distance from the wall. You need to provide the hand with a clear, continuous pathway for the entire length of the railing. Also, while not specified by code, make sure that the handrail brackets do not interfere with hand movement.

Minimum Distance Between Two Railings: 27 Inches

Minimum distance for two railings refers to the walking space between two handrails on the same staircase.

When you have two railings (one on each side of the stairwell) those railings must be at least 27 inches apart from each other, measuring between the inside (stair-side) surfaces of both handrails.

Note that this code requirement works in conjunction with the requirement about ​the maximum projection of railing from the wall. This code is important because it provides for enough room for a person to walk and carry items up or down the stairs.

Minimum Railing Distance, One Railing: 31 1/2 Inches

Minimum railing distance means the walking space between a handrail on one wall and an adjacent wall that has no handrail.

When you have just one railing on a staircase, the inside (stair-side) edge of the railing must be at least 31 1/2 inches away from the wall on the other side of the staircase. Measure this distance from the side of the handrail closest to the wall and extend the line to the wall.

When you have only one railing, you have more walking path width available than if you had two railings. The 31-1/2-inch minimum distance provides a full 4 1/2 inches more width than the double railing minimum.

Guard Railing Minimum Height: 36 Inches

Guards are the rails that protect users from falling off of high areas, such as landings. Landings can be intermediate horizontal sections within a staircase or terminal sections at the top or bottom of a staircase.

Horizontal walking surfaces with a drop-off more than 30 inches down must be protected by a guard. The minimum height for this guard is 36 inches.

As with exterior decking, no guards or rails are needed if the surface is close enough to the ground: 30 inches or less. The theory is that a person may become injured by falling off of an 18 inch-high deck, for example, but nowhere near as severely as if that person fell 8 feet down.

Even though building code does not require a guard for surfaces that are lower than 30 inches, it is always safest to include one in these situations.