Staircases seem simple. You walk up them, you walk down them. In reality, staircases are one of the most code-regulated parts of any building, and they are also one of the most common sources of serious injury. When a staircase is built wrong, someone eventually falls, and that fall often leads to a lawsuit. In construction liability cases, building code violations involving stairs are a goldmine for plaintiffs and a nightmare for contractors. The rules exist for a reason, and ignoring them is not just sloppy—it is legally dangerous.

The vast majority of staircase-related code violations fall into three categories: rise and run dimensions, handrail and guardrail requirements, and tread surface conditions. Each one carries specific legal consequences.

First, the rise and run of a staircase must be consistent. A riser is the vertical part of the step. A tread is the horizontal part you step on. Most building codes require that the rise cannot exceed a certain height, usually around seven and three-quarter inches, and the tread depth must be at least ten inches. But the real legal trap is inconsistency. You can have a staircase with risers that are, say, seven and a half inches each, and that is legal. But if one riser is seven and a half and the next is seven and three-quarters, even that quarter-inch difference creates a trip hazard. The human brain learns the pattern of the stairs after the first few steps. When a step breaks that pattern, you stumble. In court, that quarter-inch difference is enough to establish negligence. The contractor who built the stairs knew, or should have known, that the code demands uniformity. Failing to check that every riser matches is a clear violation, and a jury will see it that way.

Second, handrails and guardrails are not optional decorations. A handrail must be installed on at least one side of a staircase, and in many commercial or multi-family residential buildings, both sides are required. The handrail must be graspable—not a piece of decorative wood that you cannot comfortably close your hand around. It must be continuous from the top of the stairs to the bottom. A gap in the handrail, or a handrail that ends before the last step, is a violation. Guardrails, the barriers on the open side of a staircase or landing, have their own height and spacing rules. The typical code requires a guardrail height of at least thirty-six inches in commercial buildings and thirty inches in residential. The balusters or infill must be spaced so that a four-inch sphere cannot pass through. Why four inches? Because that is the size of a small child’s head. If a child gets stuck, that is a code violation. If a child falls through, you are looking at catastrophic injuries and a massive liability case.

Third, the surface of the tread itself matters. Slippery stairs cause falls. The code often requires slip-resistant treads, especially on exterior stairs or in areas where water or mud is likely. Some contractors put down smooth wood or polished concrete, thinking it looks nice. It may look nice, but when a visitor slips on a rainy day, the contractor is on the hook. The standard is reasonable safety, and a slippery staircase that violates the adopted building code is unreasonable as a matter of law.

When a building code violation exists and someone gets hurt, the legal theory is usually negligence per se. That means the violation itself is enough to prove that the contractor was careless. You do not need to prove that a reasonable contractor would have done differently—the code already told you what to do, and you did not do it. The plaintiff only has to show that the violation caused the injury. For example, a guest at a vacation rental trips on a staircase where the risers are uneven. The guest breaks a hip. The contractor who built those stairs can point to his good intentions all day long, but the code says risers must be uniform. The violation is clear, and the contractor will almost certainly lose the case.

But the legal exposure does not stop with the contractor. In a construction liability case, the general contractor, the subcontractor who built the stairs, the architect who designed them, and even the property owner can all be named in a lawsuit. Every party in the chain has a duty to ensure the staircase meets code. The general contractor has a duty to supervise. The architect has a duty to design to code. The owner has a duty to maintain. If the staircase was built to code but later modified improperly, the owner might bear the risk. If the architect specified a staircase that does not meet code, the architect is liable. The courts do not let anyone pass the buck when a person is lying in a hospital bed with a broken spine.

The most common way these cases settle is by looking at the severity of the injury and the clarity of the code violation. A minor violation with a minor injury might be settled for medical bills and a few thousand dollars. A major violation—like a missing guardrail on a second-floor landing that leads to a child falling twelve feet—can result in a verdict in the millions. Insurance companies know this. They will often settle quickly when the code violation is undeniable. But a contractor who fights a clear stair code violation in court is almost always making a mistake. The jury sees the photos of the stairs, hears the code language read aloud, and then sees the plaintiff in a wheelchair or with a permanent limp. The verdict is rarely in favor of the builder.

The bottom line for anyone in construction: staircases are not an area to cut corners. Measure every riser. Test every handrail. Check every baluster. The extra fifteen minutes of work to verify compliance can save you years of litigation. In a construction liability case, a broken staircase code is a broken career.