Stair Width for Safe Evacuation Under Israeli Rules

t389-32

Stair width for evacuation in Israel must be set by the applicable building code and fire safety requirements for the specific building, with the clear width measured between handrails or walls. The required width depends on occupancy load, the number of persons served and the number of exit routes, so the calculation should be confirmed with the project engineer and fire consultant before the steel staircase is designed.

Why stair width matters in an emergency

An escape stair has to carry people out of a building quickly and safely, often while they are stressed and moving in a crowd. The width of the stair controls how many people can pass through per minute, so it directly shapes evacuation time.

For architects, the key point is that width is not a decorative choice. It is a capacity decision that connects the stair to the floor plan, the occupancy of each level and the route to the public exit.

What Israeli rules generally cover

Israeli building and fire requirements set minimum clear widths, landing sizes and rules for how stairs connect to protected exit routes. These requirements apply to new construction and are often referenced when renovating or adding an escape stair.

Clear width between walls or handrails
Landing dimensions and turning space
Number of stairs serving the building
Protection of the stair enclosure

The exact values should be taken from the current regulations and checked with the engineer for each project.

How capacity is calculated

Capacity is usually estimated from the number of occupants on the floors served by the stair. Designers multiply occupant load by the factor set in the rules to determine the required width, then confirm that the chosen width is not less than the minimum.

Where several floors discharge through one stair, the load accumulates downward. The lowest section often governs, so it must be checked carefully rather than assumed from the upper floors.

Handrails, projections and clear width

Clear width is measured after subtracting anything that narrows the path, such as handrails, wall-mounted fittings, pipes or ornamental elements. A stair that looks wide on drawings can become narrow once these items are included.

Handrails should be placed according to the Israeli railing standard SI 1142 and the building requirements. Confirm the handrail projection and grip size with the engineer so the stated clear width is accurate on site.

Steel stair design considerations

Steel staircases offer strength and slim profiles, which suits tight evacuation routes. Stringers, treads and landings should be detailed so the walking surface remains even and the finished width matches the approved drawing.

Finishes such as hot-dip galvanizing or powder coating add thickness to some members. Include these tolerances in the drawing so the installed clear width still meets the requirement.

Verifying the design before construction

A simple verification process reduces risk. Gather the occupancy data, confirm the governing requirements, draw the stair with dimensioned clear widths, and have the fire consultant review the escape strategy.

Confirm occupant load per floor
Dimension clear width after handrails
Check landings and headroom
Review the drawing with the fire consultant

Frequently asked questions

Is stair width the same for every building in Israel?

No. The required width depends on the building type, occupancy load and the number of exits, so each project needs its own check against the applicable requirements.

Does the handrail count toward the stair width?

In most cases the clear width is measured after handrails and other projections are subtracted. Confirm the method with the engineer for your specific project.

Do I need a fire consultant for an escape stair?

For many buildings the fire strategy and escape routes are reviewed by a qualified consultant. Involving one early helps avoid redesign later in the approval process.

Can a steel staircase meet evacuation requirements?

Yes, steel stairs can meet evacuation requirements when designed with the correct clear width, landings and handrails. The detailed design should be verified against the applicable rules.

Common mistakes to avoid

A common mistake is measuring stair width to the wall or handrail face without subtracting projections, which overstates the clear width. Another is forgetting that lower floors may carry the combined load of all upper floors.

Our recommendation

Dimension the clear width on the drawing after all handrails and fittings, and confirm the occupancy calculation with the fire consultant before the steel stair is fabricated.

Summary

Stair width for evacuation in Israel must be verified against the governing rules using occupant load, clear width after projections and the building's exit strategy. Early coordination with the engineer and fire consultant keeps the design safe and compliant.

השאירו פרטים ונחזור אליכם