Stair Railing and Guard Building Code Guidelines

Interior Stair Railing

Janja Milosevic / EyeEm / Getty

At first glance, some building codes might seem capricious, even impenetrable and mysterious. Not so with staircase building code for hand railings and guards.

Staircase code is rooted in a set of solid ideas that all revolve around the notion that gravity isn't our best friend on staircases. So, the staircase code dictates that there must be handrails on the incline portion of stairs and guards on the horizontal parts. It also drills further down into the details and says just how high or low they should be and how far out they should project. In short, handrail and guard code is a type of building guide—a set of commonsense ideas that you can follow when building your stairs.

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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.

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

Terminology: Stair Railing and Stair Guards

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.

Stair Railing Building Code
Stair Section Requirement Notes
Handrail Height 34 to 38 inches The distance between the stair nosing and top of the railing.
Maximum Projection of Railing From Wall 4-1/2 inches This rule is designed to provide enough walking space up and down the staircase.
Minimum Hand Clearance From Wall 1-1/2 inches This rule is designed to provide clearance for the hand on the railing.
Minimum Distance Between Two Railings
 
27 inches This is the distance between two railings on two walls, opposite to each other.
Minimum Railing Distance, One Railing 31-1/2 inches This is the distance between a single railing and a wall on the other side.
Guard Railing Minimum Height 36 inches This is a minimum only. The railing can exceed 36 inches with no limit.

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

The 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 the 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

The 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 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.