trapphus

Trapphus is the enclosed vertical space in a building that contains the stairs and connects all floors. In Swedish architectural terminology, a trapphus functions as the primary means of vertical circulation and, crucially, as a fire-escape route. It typically runs from the ground floor to the top floor, with doors on each level opening into corridors or housing units.

A typical trapphus includes a stair flight, landings on each floor, handrails on both sides, and fire doors separating it from other building spaces. The walls and floors are usually made of fire-resistant materials such as concrete or masonry, and the stairwell is often a dedicated fire compartment to limit smoke and heat spread. Lighting, signage, and sometimes natural light via windows are common components.

Regulatory and safety aspects: Building codes require trapphus to provide safe egress under emergency conditions. This includes fire-resistance ratings for walls and doors, minimum width requirements, emergency lighting, and clearly marked routes. In many jurisdictions, stairwells must be separated from elevator shafts and other spaces by fire doors and may be equipped with sprinklers or smoke control systems in larger buildings.

Accessibility and maintenance: As part of accessibility planning, trapphus should have handrails on both sides, high-contrast surfaces, and clear pathways. Regular maintenance ensures doors seal properly, lighting is functional, and corridors are free of obstructions. In historic buildings, original railings and finishes may be preserved while meeting safety standards.